[. 373 1

XIII. 0 9 8 soi?ze New British Polyno’ina. BJI E. RAY LAKKESTER, Xgp. Conzmzcizicated by J. G. JEFFREYS, Esq., F.Z.8.

(Plate LI.)

Read January 18th, 1866,

1\HE species described in the following pages were collected by me while in Guernsey, last summer, with my friend Mr. Gwyn Jeffreys, dredging under the grant of the British Association. I have had very great difficulty in studying the Aiinelida obtained thence, as every systematic work on these animals with which I am acquainted, in either French or English, is most unsatisfactory and imperfect. Prof. Malmgren’s work on the North-Sea Annelida, now in course of publication, has given me much valuable as- sistance, as also Prof‘. Kinberg’s work in the ‘ Voyage of the Eugenie.’ Both of these are written in the Swedish language; but the descriptions and much valuable matter are given in Latin. I have endeavoured, as far as possible, to take Prof. Malmgren’s descriptions of species as my model, and have, I hope, succeeded in making my de- scriptions uniform with his. I have, however, introduced one or two alterations in the nomenclature, mainly as suggested by Prof. Huxley in his Lectures on General Xatural History. Thus all the somites in front of the mouth are called the “prostomium,” and the temtaculum is called theprostomial tentacle. l’he somite round the mouth is called the pe.i.istomiwn, and its appendages, usually known as temtacular cirri, are called peri- stomial cirri. Each foot is called a parapodizcm, and divided into a notopodium and a fzeuropodium, corresponding to the ‘‘ rame dorsale ” and “ rame ventrale ” of dudouiu and Milne-Edwards. All the somites provided with feet are called truizcal somites, and form the t192~171c (scg- menta pedibus instructa), while the prostoniium and peristoiniuiii €orm the “ head ” ( p ~ s cephalica). The number of somites constituting the prostomiurn is a subject still re- quiring investigation, but does not come within thc scope of the present paper. T h remarkable and very varying histiological characters of the ‘‘ elytra ” in the Polynoina are also exceedingly interesting, and might be made to furnish generic characters readily as the form of the set%. Nearly all the Annclida now to bc described wer(’ obtained under rocks and stones at low-water mark.

The segment beyond the anus is denoininatecl ccp~gidium.”

HARMOTROE (Kinberg).

Body oblong. Antenme attached under the base of the prostomial tentacle, which oe- cupies a frontal incision of the cephalic lobe. Palps broad, subulnte ; to the naked eye quite smooth, but found with the microscope to be densely covered with minute papilla Elytra fifteen or twenty pairs, usually covering the whole back, placed on 1, 3, 4, 6, 8

VOL. XXV. 3 G

374 MR. E. R. L A N K E S T E R O N N E W BRITISH POLYNOINA.

. . . . . . 22, 25, 28, 31, or 32, 35,38,41 truncal somites *. Set% of notopodium slightly attenuated towards the apex, with minute spicules disposed in dense transverse series. Set= of the neuropodium thinner and longer, and transversely spinate from the bidentate apex.

HAIWOTHO~ SARNIENSIS, n. sp. Corpus elongatum, postice attenuatuni ; somitibus truncalibus 47.

Two pygidial (anal) cirri beneath the anus.

Lobus cephalicus latior quam longior, margine antic0 late inciso, in prominentias duas angulares a latere product0 ; oculi 4, duo anteriores in lateribus prominentiarum, sub apice earum siti. Antennze longitudine lobi cephalici. Tentaculum antennis triplo longius, arti- culo basali conspicuo. Cirri peristomiales magnitudine et formil tentaculi ; omnes filiformes, oculo nudo glabro, apice magnitudine aucto. Elytra paria 20, non semper totum dorsum tegentia, primo pari suborbiculari excepto, ovali-reniformia vel oblique ovata, oculo nudo glabro, margine externo saepe, in junioribus sem- per, breviter et paullo ciliato. Cirrus notopodialis trunci latitudinem longitudine aequans, e&dem form& et colore ac cirri peristomiales. Cirrus neuropodialis bre- vior, subulatus. Papilla ventralis distincta, cylindrico-conica, insertionem cirri neuropodialis fere attingens. Cirri pygidiales duo sub ano, cirris notopodialibus simillimi sed longiores.

Color.-Elytrorum variat, in plerisque brunneus variegatus, sEpe griseus, et szepissime deest. Set= fulva. Truncus lineis fuscis inter somites notatus.

Longit. 4-5 centimetres. Latit. 8-0 millimetres (cum setis).

Hub. vulgatissime ad oras orientales insula: Sarnis (Guernsey), et ad oras occidentales insula: Hermi. Tab. LI. fig. 14. Hurmothoe Surniensis; fig. 10. Pars cephalica, aucta; figs. 15, 16. Elgtra; fig. 24. Valde

The species above described is very abundant under stones near the low-water mark at Guernsey and Herm. It is remarkably active, and has the habit, so common and fatal among this beautiful group of Annelids, of breaking up into bits when touched. I ts chief peculiarity is the presence of twenty pairs of scales-a larger number than has, 1 believe, been met with in any of the allied gibbous Polynolna. I n many respects it is closely related to the Lepidonotus cirratus of Johnston (Harmothoe imbricata, Malm- pen) , to which in colour it is very similar, whilst the head does not differ much in folyn, and the set= are identical. The presence of twenty pairs of scales, however, and the consequent presence of forty-seven truncal somites, seems to draw a very marked line between the two species ; whilst, moreover, in H. Sanziensis the scales frequently leave a portion of the body of the animal exposed between them in the middle line, and are very delicate and small. I n Guernsey and Herm not a single specimen referable to 1% iii~bricuta (Lepidonotus cil*ratus) occurred. I ts place seems t o be entirely supplied by this species. The special food of H. Surniemis is, I believe, small rnollusca and N emertian s.

aucta elytri pars.

* I n Prof. Malmgren’s and other works, the somites are spoken of as “ segments,” and are separated as ‘ 6 segments provided with feet ” and “segments destitute of feet.”

MR. E. R. LANKESTER ON NEW BRITISH POLYNOINA. 375

HARMOTHOE MALMGRENI, n. sp. Corpus oblongum, ovatum, postice attenuatum ; somitibus truncalibus 37. Lobus cepha-

licus latior quam longior, niargine antic0 rectc incise, nec lateraliter product0 ; OCU-

lis 4, duo anteriores laterales, duo posteriores in vertice. Antennz longitudine lobi cephalici, articulis basalibus. Tentaculurn antennis ter longius, articulo bas& elongato. Cirri peristomiales niagnitudine et form$ tentaculi, articulo basali valde elongato. Cirri buccales conspicui. Palpi permagni, crassi, apice attenuati. Elytra, primo pari suborbiculari excepto, ovali-reniformia, glabra, tenuissima, pellucida. Set= notopodiales setis E. iwzhricat~~ sirnillimE, Set= neuropodiales long=, tenues, spinulis longis usque ad apicern armatz.

Color.-Elytra sine colore. Set= fulvz. Longit. 50 millim. Latit. 10-11 millim.

Hab. in tubulis Chcptopteri insignis ad oras insulze Hermi.

Tab. LI. fig. 11. Pars cephalica, aucta; fig. 25. Elytron, auctum; fig. 28. Seta neuropodialis, aucta.

This species, which I have named after M. Malmgren, who has done so much good work among the Annelids, as well as in other branches of zoology, was found in the tube of a Ch~~iopierzcs, which is by no means rare at Herm. It appears t o be only met with in this habitat, and I would just draw attention to the fact that nearly all the Polynoina are thus parasitic *. Dr. Baird mentions a species of Lepidonotzis as occurring in the tubes of a Chetopterzcs from Anglesea (which he has called Ch. insignis), and I have seen. the specimens in the British Museum; it is, however, quite distinct from H. Nalmqrelzi, and much more closely allied to H. imbricata ( J . cirratzis). The horizontal direction of the anterior margins of the cephalic lobes, and the absence of anything like a prolongation of their frontal margins, together with the presence of a large basal pro- tuberance for the antennz, are the points chiefly noticeable in this species. The scales also are of very great tenuity. The colour and form also of the cirri and their homo- lopes are characteristic.

ANTINOE (Kinberg). Antenn2e arising from the base of the tentacle, which occupies a frontal incision of

the cephalic lobe. Palps subulate, densely covered with very minute papillae. Elytra fifteen pairs (in smaller forms only thirteen to fourteen), covering the whole back. Noto- podia1 set% divaricate, towards their extremity densely transversely spinulose, (excepting the innermost) a little curved, shorter and much broader than the set= of the neuro- podium; these are capillary, numerous, spinulous, much elongated, with a very fine apex. Two pygidial cirri beneath the anus.

ANTINOE NOBILIS, n. sp. Corpus oblongum, utrinque fere equaliter obtusum ; somitibus truncalibus 30-36. Lobus

cephalicus aeque longus ac latus, antice et postice valde incisus, antice in duas prominentias conicas productus ; oculi 4, duo postice in vertice, duo antice majores

* Prof. Huxley mentions a species in his lectures which he has called P. astericola, from its infesting Uraster. 3 G 2 *

376 MR. E. R. LANKESTER ON NEW BRITISH POLYKOINA.

laterales. Antennae minutae, deciduz, tamquam a prominentiis lobi cephalici orientes sit%. Tentaculum prostomiale inter prominentias frontales magno articulo liasali insertum, dense ciliatum, apice aucto, lob0 cephalic0 plus quam ter longius. Cirri peristomides form& et magnitudine tentaculi. Elytra dura, tuberculis nodu- lisque duris armsta, primo pari suborbiculari except0 reniformia, margine tuber- culis acutis valde deutato postice et externe parce ciliato. Cirrus notopodialis pyri- formis, sacculatus, ciliatus, brevis. Cirrus neuropodialis subulatus, breviter ciliatus. Papilla ventralis conspicua.

Color.-Elytra brunnea, pellucida, pulcherrime maculata. Truncus passim aurantiaco-

Longit. 3&4$ centimetres. Latit. 1-1.2 centimetres. Hub. haud vulgatissime ad oras occidentales insulze Hermi, fundo lapidoso.

ruber. Set.& fulva.

Tab. LI. fig. 1. Antinoe nobilis; fig. 2. Pars cephalica, aucta, dorsum; fig. 4. Pars cephalica, aucta, ventrum ; fig. 3. Parapodium; fig. 5 . Elytron, valde auctum; fig. 6. Pars elytri; fig. 7. Cirrus notopodialis; fig. 8. Seta notopodialis ; fig. 9. Seta neuropodialis.

This very handsome species I obtained only at Herm, and there by no means com- monly. It was invariably found close to and in the tubes of Terebellcc me6zdosa, on which -4nnelid it apparently feeds. The bright salmon-red colour of both is remarkable. Nearly every species of Polyno’ina appears to have its special victim ; and 2”. mebuloscc undoubtedly serves this form.

The remarkable form of the notopodial cirri in this species is well worthy of attention ; they are invariably as it were inflated, SO as to have aii almost globular appearance, instead of being filiform as is usual. The only other, similar instance I have noticed is in a species described by Schmarda as Cmtrolepidia clavigera.

The colour of the optic lobes is violet, whilst the palps, which are long and exces- sively sensitive, are deep madder-brown; the orange-red colour of the body, which is seen through the tough but translucent elytra, renders this a very fine-looking species. The peculiar dentation of the edges of the elytra and their other markings (see plate) are produced by the extraordinary development of the marginal cells, which are usually simply disposed in the tissue of the scale. The growth of these cells is such that they press one against another, and thus become hexagonal and elongated where the lateral pres- sure is greatest.

I have had some doubts as to whether this form rightly belongs to Kinberg’s genus Antinoe, but I am unwilling to multiply names at present by instituting a fresh genus for its reception.

I n the British Museum there is a large specimen of this species without its elytra or cirri, labelled Lepidonotzcs semisczc@tzcs, Leach. On turning to the catalogue lately published, I find the description of a very different worm and a reference to a drawing of tt Aepidotzotus with twenty pairs of scales, which is rather puzzling. Hence I conclude that this species is certainly not the L semisczdp f~~ of Leach, whose original type has been lost.

MR. E. R. LANKESTER ON NEW BRITISH POLYNOINA. :377

ANTINOE ZETLANDICA, n. sp. Corpus late pyriforme, antice latius, postice subito attenuatum. Lobus cephalkus

zeque longus ac latus, antice duas prominentias maximas przebens ; oculi 4, duo postici in vertice, duo antici laterales. AntennE filiformes, lob0 cephalico sesqui- longiores. Tentaculum inter prominentias frontales insert um, articulo basali magno. Palpi validi, percrassi. Elytra densa, dura, tuberculis marginalibus, p r i m pari suborbiculari except0 reniformia.

Cotor.-Elytra brunnea, interne margaritacea. Longit. 50 millim. (circiter). Latit. 35 millim. (circiter) cum setis.

Hub. ad oras Zetlandicas.

Set= fulvz.

Tab. LII . fig. 13. Pars cephalica, aucta; figs. 17,18. Elytra; fig. 22. Scta neuropodialis ; fig. 23. Sctano- t opodialis .

This species was dredged by Mr. Gwyn Jeffreys in Shetland, and deposited by him in It is chiefly remarkable for its great breadth and the large size of

The tentaculum is deficient in the specimen, and some of the British Museum. some of its elytra and set=. the elytra also.

HALOSYDNA, Kinberg. Cephalic lobe .anteriorly tripartite, for the purposc of forming the bases of the prosto-

mial tentacle and of the antennz. Elytra eighteen to twenty-one pairs, not always covering the back, extending to the end of the body, but not affixed to the few posterior somites.

Subgenus ALENTIA, Malmgren.

Body linear oblong. 6, 8 . . . . . 22, 25, 28, 31, 34, 37, 38. very obscurely serrulate. others, numerous, bidentate at the apex, with very few spinules.

Elytra eighteen pairs, on the following truncal somites : 1, 3, 4, Set8 of the notopodium hair-like, not numerous,

Set= of the neuropodium much longer and broader than the

HALOSYDNA (ALENTIA) JEFFREYSII, n. sp. Corpus lineare depressiusculum, utrinque aqualiter obtusum ; somitibus truncalibus 43.

Lobus cephalicus latus, lateribus rotundatis ; oculis 4, utrinque duo approximati. Tentaculum lobo cephalico quadruplo longius. AntennE eL cirri tentaculares formb, et longitudine tentaculi. Palpi vdidi, crassi, glabri, his longiores. Elytra tenuissima, mollia.

Color.-Truncus brunneo-violaceus, lobus cephalicus purpureus. Set= f d v z . Longit. 60-70 millim. Latit. 14-16 millim. (cum setis). Hab. ad oras insulze Hermi et Britannize australis.

Tab. LI. fig. 12. Pars cephalica, aucta; figg. 19, 20, 21. Somites truncales 1, 2, 3 ; figg. 26, 27. Set=.

This species, which I met with at Herm, is, I believe, the same as that narned Lepido-

378 MR. E . R. LANKESTER ON NEW BRITISH POLYNOINA.

fzotus imbricutus in the British Museum, and briefly noticed in the Catalogue. The Aphrodita imbricata of Linimus is considcred by Malmgren to be identical with L. cir- ratus of Johnston and Audouin and Milne-Edwards ; and hence the name imbricatus must be changed. I propose to give the specific title Jefreysii to this form, in honour of my friend Mr. Gwyn Jeffreys, F.R.S., throagh whose kindness I have been able to make these few remarks on the Aniielida of Guernsey. The Alentia gelatinosa of Sam, Kinberg, and Malingren appears to be very closely allied, and may perhaps turn out to be but a boreal forin of the same species. The description which I have given above is very similar to that given by Malmgren of A. gelatinosa.

,

DESCRIPTION OF THE PLATE.

PLATE LI. Fig. 1. Antinoe nobilis, n. sp., natural size. Fig. 2. Head of A. nobilis, viewed from above : a, prostomial tentacle; 6, base of the prostomial tentacle ;

Fig. 3. Parapodium and appendages of A. nobilis. Fig. 4. Head of A. nobilis, viewed from below : letters as before ; g, neuropodial cirrus of the first

Fig. 5. Elytron of A. nobilis, highly magnified, showing the peculiar arrangement of the endoplasts. Fig. 6. A portion of the margin of the same elytron, viewed from below. Fig. 7. Neuropodial cirrus of A. nobilis. Fig. 8. Notopodial seta of A . nobilis. Fig. 9. Neuropodial seta of A. nobilis. Fig. 10. Head of Harmothoe Sarniensis, viewed from above. . Letters as before. Fig. 11. Head of Harmothoe Malmgreni, viewed from above. Letters as before. Fig. 12. Head of Hulosydna Jefieysii, viewed from above. Fig. 13. Head of Antino2 Zetlandica, viewed from above.

the prostomial tentacle are wanting. Fig. 14. Harmothoe Sarniensis, natural size. Guernsey. Figs. 15,16. Elytra of H. Sarniensis. Figs. 17,18. Elytra of A. Zetlandica, twice natural size. Fig. 19. First truncal somite of H. Jefieysii. Fig. 20. Second ditto. Fig. 21. Third ditto. Fig. 22. Neuropodial seta of A. Zetlandica. Fig. 23. Notopodial seta of A. Zetlandica. Fig. 24. Portion of the elytron of H. Surniensis. Fig. 25. Elytron of H. Malmgreni. Fig. 26. Neuropodial seta of Hulosydnu Jefleysii. Fig. 27. Notopodial seta of ditto. Fig. 28. Neuropodial seta of H. Malmgreni.

Herm.

c, antennz; d, cephalic or optic lobes; e, palps; f, peristomial cirri.

truncal somite, or ‘(buccal cirrus.”

Letters as before. Letters as before. The peristomial cirri and