388 A. E. Verrill — Marine JSTemerteans of Neio England^ etc. 



among a large number of genera by the earlier writers, especially 

 by those who did not observe the armature of the proboscis, or did 

 not consider it of importance. 



In general, it is impossible to distinguish the species of this genus 

 from other genera without an examination of the proboscis and its 

 armature. Hence, no doubt, there are many still unrecognized 

 species of the genus that were formerly described under other 

 genera, from various foreign countries, I believe, however, that all 

 the species hitherto described or mentioned as found on our coast 

 are included in the following list, together Avith several that appear 

 to be undescribed. 



CErsted adopted Polystemnia for this genus, and placed under it 

 two typical species; P. roseum and P..pnlchmun. At the same time 

 he restricted Amphiporus to the genus named Nemertes (new sense) 

 by Mcintosh, giving its essential character (a small proboscis) and 

 naming A. Neesii as the type. 



Subgenera of Amphiporus. 



The genus may be conveniently divided into several groups or 

 subgenera based primarily on the arrangement of the ocelli and 

 nerves, as follows : 



I. Ocelli form four or more distinct groups ; the two cerebral groups are 

 distinct from the anterior ones. — Omnia toplea, subgenus. 



lo. Anterior ocelli do not form curved rows parallel witli the lateral 

 margins of the head. 



Amphiporus angulahis (Fabr.). 

 A. multisorus V., sp. no v. 

 A. heterosorus V., sp. nov. 

 A. tetrasorus V., sp. nov. 



lb. Anterior groups of ocelli form curved rows parallel, at least in 

 part, with the sides of the head. — Polysieinma (Ers. ; Polina 

 Stimp. 



^4. roseus (Miiller). 



A. lactifloreus (Johnst.). 



A. ochraceus V. 



A. glutinosus V. 



A. griseus (Stimp.). 



would have justified him in not making the change before there was any proof of the 

 necessity for doing so. 



The cliange having been made in so important a woric, lias been generally adopted 

 by later European authors, and I have, therefore, followed their example in this 

 article, for uniformity of nomenclature in this group is at present of paramount 

 importance. 



