PANTHALIS CERSTBDL 401 



1876. Panthalis (Erstedi, Mcintosh. Trans. Z. S., ix, 389, 404, 405. 



1879. „ „ Tanber. Ann. Danic,, 83. 



1883. „ i9 Levinsen. Xord. Annul.,, 197. 



1893. „ }} Marenzeller. Polychaet. des Grnndes, 5, Taf. 1, f. 2. 



1895. „ i} Arnold Watson. Trans. Liverpool Biol. Soc, ix, 1895, 169, pis. ix and x. 



), ,', Lacaziij Pruvot and Eacovitza. Arch. Zool. exper., 3rd serie, hi, 428, pi. xix, f. 



84—104. 



» „ Marenzellerij idem. Ibid., 442, pi. xix, f. 105 ; and pi. xx, f. 106 — 110. 



Habitat. — First dredged in Britain by Dr. Gwyn Jeffreys in 78 fathoms, 35 miles off 

 Skerries, Shetland, in 1868 ; 358 fathoms in the Atlantic (station 6) during the ' Por- 

 cupine ' Expedition of 1870 ; by the ' Triton ' at 516 fathoms ; and recently in the Irish 

 Sea by Prof. Herdman and Mr. Arnold Watson. It stretches to the Mediterranean, 

 medium-sized examples having been procured in 40 to 80 fathoms off Jigeli in Algiers, 

 in 40 to 80 fathoms during the 6 Porcupine ' Expedition of 1870 ; while Marenzeller 

 obtained it in the eastern part of that sea off Jaffa. It is also found off Norway and 

 Sweden. Its distribution is thus extensive. 



The head (Plate XXVIII, fig. 16) is somewhat urn-shaped in the preparations, with 

 the rounded bosses for the eyes in front laterally, and the median tentacle in the centre, 

 then dilating from the bases of the former, and again narrowing posteriorly where it 

 runs into the body, without a nuchal collar. The smoothly rounded tips of the ocular 

 peduncles retain no pigment in the preparations; but in life, besides the ocular pigment, 

 the peduncles are reddish. Pruvot and Eacovitza consider them the homologues of the 

 lateral peaks of the Polynoidse — a supposition to which little objection can be taken, 

 since they occupy the whole anterior region of the head. The median tentacle arises 

 rather behind the bases of the ocular peduncles, and thus is behind the middle of the 

 entire region (including the ocular peduncles). Its basal region is short, while the 

 tentacle itself is a somewhat small subulate organ with a tapered tip which extends 

 beyond the peduncles. The lateral tentacles arise close together beneath the ocular 

 peduncles ; and their tips reach a little further than that of the median. The palpi are 

 flesh-coloured, long, tapering, and with minute conical papillse which commence a little 

 above the base and extend almost to the extremity, only a very short portion of the 

 filamentous tip being bare. They are very minute inferiorly, but increase in size distally. 

 Moreover each papilla has a basal granular region, and a clear tip like a jewel in its 

 setting. The tentacular cirri are longer and stronger than the median tentacle, though 

 much shorter than the palpi. 



Body 3J inches and upwards in length, tapering a little in front and more distinctly 

 posteriorly. The dorsum is pearly white in front, flesh-coloured posteriorly, the red dorsal 

 blood-vessel enlivening the general hue of the finely and transversely striated integument. 

 Inferiorly is the deep median furrow and two lateral ridges, the former terminating in 

 front in a broad shield-shaped area. The ventral surface in life is opalescent, with a 

 golden shade towards the sides. Mr. Arnold Watson describes the posterior extremity as 

 being broadly forked from the backward direction of the last pair of feet. No complete 

 specimen, perhaps, has been seen. Anteriorly the segmental eminence is very slightly 

 indicated, but it forms a distinct elevation posteriorly. No papilla is visible. 



