220 OPHELIACE.I:. 



1. T. Forbesii. Plate XIX. figs. 11-18. 



Travesia Forbesii, Johnston in Ann. Nat. Hist. iv.37S. pi. 11. f. 11-lS 



(1840). 

 Auimotrypane cestroides, H. Rathke in Nov. Act. Acad. Nat, Cur. xx. 



192 (184;^), tab. 10. f. 9-12. 

 Ophelia mamillata. Oersted, Annul. Dan. Consp. 45 (1843); Groenl. 



Annul. Dorsibr. 53. pi. 8, f. 103, 112, 114, 119, 120. 

 Travesia c»stroides, Grube, Fam. Annel. 71. 



Hab. The coralline region. 



Besc. In figure this Annelide is something between that of the 

 earth-worm and the leech : it is elliptical antei'iorly, narrower and 

 subcylindrical in the posterior half, of a uniform dull olive-green 

 colour, smooth to the naked eye, distinctly annular. Both sides are 

 so alike, that it is not easy to say at first which is the dorsal and 

 which the ventral ; but the anterior segments are so far unlike the 

 posterior ones, that, to render the description more distinct, it may 

 be advisable to consider it as divided into an anterior and "a caudal 

 half. 



The anterior half consists of about fourteen segments, increasing 

 gradually in diameter till near the middle, when they begin again to 

 decrease a little. The first or cephalic segment is very small, pellu- 

 cid, triangular, sharp-pointed like a snout, and somewhat concave 

 underneath ; it is destitute of every kind of appendage. The second 

 segment is rather broad, and like the succeeding, excepting that it is 

 single and without any armature. The other segments consist each 

 of two, or sometimes three narrow rings ; and each of them is fur- 

 nished, on each side, with a dorsal brush of bristles, a long filament, 

 a circular pore, and a ventral brush of bristles, similar to the dorsal, 

 but smaller. On the secondary or intermediate rings there are no 

 bristles, but one, two, or even three pores. The mouth is perforated 

 between the third and fourth segments on the ventral surface ; it is 

 circular, with thickened puckered lips, edentulous, and without a 

 proboscis. 



The anterior segments pass by a sort of gradation into the caudal 

 ones, though it is not difiicult to mark the distinction. They are 

 less in diameter, but broader in the opposite direction, and thickened 

 on the sides, where there are two short obtuse fleshy papillse. From 

 the base, and below the dorsal papilla, the soft filament or cirrus 

 originates, which does not exceed half the length of the anterior 

 filaments. Close to the cirrus there is a brush of bristles, but I 

 could not discover a second brush. There are thirteen of these cau- 

 dal segments vnth a very narrow one between each : the last but one 

 is small and unarmed, and the anal one is terminated with six soft 

 obtuse papillae, forming a sort of cup-like circle round the vent. 



The skin of the worm, under a magnifier, appears to be granulated 

 on the dorsal, and punctured on the ventral surface. The bristles 

 are slender, unequal, slightly curved, acicular, smooth, and unjointed ; 

 they vary in number in the segments, but scarcely exceed twenty in 

 any single fascicle, and arc never fewer than four or five. Those of 



