450 
THE VOYAGE OF H.M.S. CHALLEHGEE. 
The examples collected by the naturalists of the Challenger appear to be smaller than 
those found by Schmarda, who gives the length at 150 mm. It is probable, however, 
that this author refers to the condition in the living animal. 
The general aspect of the Annelid somewhat resembles the common Nicolea from 
the Channel Islands, the dorsum being minutely corrugated all over by longitudinal 
folds. The latter condition is most distinct anteriorly, but is also quite visible toward 
the anus. 
The somewhat slender cephalic tentacles are in immense profusion. No ocular specks 
are present, the species agreeing in this respect with its ally from the Channel Islands ; 
and the same may be said of the buccal region. The branchiae are stated by Schmarda 
to be three, but there is probably a mistake in regard to number, as the structure of the 
bristles and hooks would lead us to expect only two. The first arises on each side from 
the second segment as a dense bush supported on a stout though short pillar terminating 
in many branches. The ultimate divisions are short, and give a curled aspect to the 
surface of the bush. The second branchia is attached to the third segment, and is 
considerably smaller. This species has much shorter terminal divisions than that from 
the Channel Islands. It agrees with Nicolea in having two branchise, but differs in 
other respects. 
Instead of having fifteen pairs of bristle-bundles as in Nicolea, there are thirty-three, 
the first springing from the fourth segment ; while the shape of the process on which they 
are borne, and the structure of the bristles themselves, are quite different from those 
in the form alluded to. The bristles spring from elevated vertical ridges, those at the 
dorsal edge (PI. XXVII a. figs. 24, 25) consisting of elongated winged forms, somewhat 
after the usual type, but their slender tips are pectinated in every instance, though it is 
not always visible in the preparations. Schmarda, indeed, mentions that the dorsal 
forms are simply winged, but he has probably overlooked the delicate pectinations. The 
tips diminish in length as we proceed downward, and the wings become broader, the 
pectinated region at the tip being longer and more evident. All follow the same type, 
the intermediate bristles having narrower wings and very distinctly pectinated tips, the 
appearances shown by Schmarda being due to imperfect examination. The pectinations 
are quite visible in the interior of the setigerous lobe, before the extremities of the 
winged bristles have been extruded. 
The hooks (PL XXYIIa. fig. 26) are peculiar, presenting superiorly in profile three or 
four small teeth above the great fang, while the posterior margin forms an almost 
continuous and uniform curve with the ventral or basal margin, a small mucro only 
indicating the separation. The ventral border is evenly convex, from its commencement 
posteriorly forward to the anterior angle. Very little change occurs in the posterior hooks. 
These organs resemble the uncini of Terehella mechelii, Delle Chiaje,^ a form, however, 
^ Claparede, Anndl. Chetop., p. 391, pi. xxviii. fig. 3. 
