524 A. E. Ve7Till — Marine Nemerteans 



MARINE NEMERTEANS. 



Dr. Girard makes no use of the structure of the proboscis and 

 body-walls in his system, and therefore some of his genera contain 

 species belonging to distinct orders : Enopla and Anopla, for exam- 

 ple. On the other hand many of his genera are based entirely on 

 trivial external characters, such as the form of the body, constriction 

 of the neck, arrangement of the eyes, etc., which are frequently not 

 even of sj)ecific value. Therefore his generic groups are too numerous 

 and often too indefinite and uncertain. 



The following genera adopted by Dr. Girard seem to have no real 

 standing, being either artificial groups or synonymous with others 

 adopted by him : 



Hecate, Poseido7%, PoUna, Borlasia, Nemertes, N'eesia, Macrone- 

 mertes, Asteontna, Hallezia, JRenieria, Leodes, MeckeliaJ ,' 



The following may be regarded as sections, or in some cases as 

 subgenera of AmpMporus : Cosmocephala, N~areda, Ophionemertes, 

 Hallezia^ Polina, 



The following may be considered as synonymous with Cerehrat- 

 ulus : Penieria, Leodes, MecJcelia. 



Several land and fresh-water Nemerteans are catalogued, which I 

 shall not here discuss. For the sake of brevity, I have omitted 

 references to the plates of my paper in vol. viii, where most of the 

 species are figured. 



In the following list the species are given in the sequence used by 

 Dr. Girard. 



Carinina grata Hubr. ; Gr'd, p. 245 =Do. Verrill, these Trans., vol. viii, p. 443. 

 Drepanophorus Lankasteri Hubr, ; Gr'd, p. 246 =Do. Verrill, these Trans., 



vol. viii, p. 415. 

 Cephalothrix linearis (Erst. ; Gr'd, p. 247 =Do. Verrill, these Trans., vol. viii, p. 



442. 

 Cosmocephala ochracea Ver. ; Gr'd, p. 249=Aniphiporus ochraceus Ver. 



vol. viii, p. 396. 

 Cosmocephala Stimpsoni Ver.; Gr'd, p. 250=r Amphiporus angulatus (Fabr.) 



Ver., vol. viii, p. 390. 



This species is again enumerated as Ophionemertes Stimpsoni, on 

 p. 277. 



Nareda superba Gr'd, p. 251=rAniphiporus (?) superbus Ver., vol. viii, p. 403. 

 Nareda pulchella Gr'd, p. 251= Poly gordius pulchellus. 



Under the genus Nareda, Dr. Girard refers to the observations 

 published in 1867, by Mr. A. Agassiz, on the embryology of a form 

 which he at that time doubtfully referred to Nareda superha. It has 



