218 



OPHELlACEiE. 



Anal extremity suddenly depressed and narrower ; the vent terminal, 

 encircled with a few short papillae, and overshadowed with the tufts 

 of bristles from each side. On the anterior portion there are six or 



No. XLI. — Ammotrypane limacina. 



1 



1. Worm entire. 



2. Proboscis exserted ? 



seven pairs of slightly developed feet, consisting of two minute lobules 

 in a transverse line, between the clefts of which the small bundle of 

 bristles is protruded. The other feet are alike, but are most developed 

 posteriorly. There are about twenty-eight pairs (exclusive of the 

 anterior), and each foot is furnished with two fan-shaped unequal 

 bundles of bristles protruded from clefts between small rounded 

 membranous lobules. The upper cleft has two lobules on each side, 

 the under cleft one only ; and above the upper cleft is the thick 

 cirriform branchia, shorter than the bristles in specimens preserved 

 in spirits. The superior fascicle of bristles is the longest and largest, 

 and the bristles are all smooth, weak and setaceous. 



Mr. Dyster thus describes it : — " Length 2^ inches ; breadth ^ths. 

 Anterior third cylindrical. Head conical ; the remaining two-thirds 

 somewhat compressed. Ventral surface divided deeply into two 

 semicircular ridges, from the outer edge of which project the feet, 

 carrying a bundle of longish setse below, and prolonged above into 

 filamentous branchiae. The anterior one-third has about eight pairs 

 of feet, resembling those of the RissuIacetE (I speak only of appear- 

 ance under a hand-glass ; is not dissected yet). The four (?) caudal 

 segments without appendages. Terminating in a circle (cluster ?) 

 of short stout conical papillae. Segments very imperfectly marked ; 

 anteriorly not at all, but body transversely ringed. Very sluggish : 

 gorgeously prismatic." 



