174 MR. H. CHARLTON BASTIAN'S MONOGRAPH 



" Some of these animals appeared among a number of the decaying corpuscula from 

 the Flustra carbasea, which they frequently penetrated as if in quest of food." — Dalyell. 



34. PONTONEMA, Leidy. 

 Proceed, of Acad, of Philad. vol. viii. (1856) p. 49. 

 Gen. Char. " Body capillary, narrowing towards the extremities. Head continuous with 

 the body, truncated or obtuse, and surmounted with angular papillse, cirrated. Eyes 

 none. Tail obtuse. Generative aperture ventral, near the middle of the body. 

 CEsophagus long, cylindro-clavate ; gizzard none, intestine straight, capacious ; anus 

 ventral and posterior." 



1. P. vacillatum, Leidy. 



Journ. Acad. Philad. 2nd ser. iii. 144, et in Proceed. Acad. Philad. viii. (1856) p. 49. 



" Body cylindroid anteriorly, with longitudinal rows of short cirri in addition to those 

 of the head ; posteriorly incurved ; tail short, thick, conical, obtuse. Length to 9 lines ; 

 breadth to \i\i of a line." 



" Rab. Pound on the sea-shore of Ehode Island, beneath stones, between tides." 



2. P. MARINUM, Leidy. 



Journ. Acad. Philad. 2nd ser. iii. 144, et in Proceed. Acad. Philad. viii. (1856) p. 49. 

 " Body cylindroid ; head convex ; mouth surrounded with angular papillae. Cirri 4, at 

 the side of the head. Tail long, narrow, conical, obtuse. Length to 3 lines." 

 " Hub. Pound at the bottom of a sound on the coast of New Jersey." 



3. P. MtJLLERi, Diesing. 



Vibrio Anguillula d. Anyuillula marina, Miiller, Anim. Infus. 66, Taf. ix. 9-11. 



Vibrio inarina, Bory, in Encycl. Meth. (1824) 778, tab. xxiv. 26.— De Blainville, in Diet. d. Sc. Nat. 



Ivii. 537, et Iviii. 71. 

 Anguillula marina, Oerst. De region, marin. 1844, 63 & 69. 

 Enchelidium marinum, Ehrenb.— Diesing, Syst. Helm. i. 127 (partim). 



" Corpus subtequale, retrorsum acutatum. Caput truncatum. Os cirrhis Longit. 



ad 1'"." 



" Mab. Inter mucosa palos marinos obvestientia, et in aqua marina servata frequentis- 



sime ( O. F. Miiller). In profunditate 0-8 orgyiarum, testate, in fretu Oeresund {Oersted):'' 



" Cum Vibrio marina, Miiller, oceUis omnino destituta sit, cum Enchelidio marino, 



Ehrenberg, identica esse non potest {Oersted, 1. c.)."— Sitzungsb. der Kais. Akad. 1861, 



(Bd. xlii.) S. 623. 



35. POTAMONEMA, Leidy. 

 Proceed, of Acad, of Philad. viii. (1856) 49. 

 Gen. Char. " Body filiform, narrowing towards the extremities. Head continuous with 

 the body, slightly dilated, obtuse. Mouth large, infundibuliform, unarmed. (Eso- 

 phagus narrow, ilexuous, membranous, gradually expanding into a capacious, straight, 



