XXII. — The Marine Nemerteans of New England and Adja- 

 cent Waters. By A. E. Verrill. 



The following article is intended as a descriptive catalogue of all 

 the Nemerteans of the North-eastern Coast of North America that 

 have been observed with enough care to permit me to give a 

 description presumably sufficient to enable ordinary observers to 

 identify the species Avhen seen living. Therefore all my own 

 descriptions, herein given, have been made from living specimens, 

 except in a few special instances, which are, in each case, particu- 

 larly stated. 



As a rule, undetermined alcoholic specimens of Nemerteans, un- 

 accompanied by notes on their forms and color's while living, cannot 

 be identified with certainty unless they belong to genera containing 

 very few and widely differing species. To distinguish the numer- 

 ous species of Atnphijyorus, Tetrastemma, Lmeus, etc., with alco- 

 holic specimens alone, would be a hopeless task, at least in the 

 present state of our knowledge of these groups. Possibly, when 

 all the known species shall have been studied thoroughl}- by means 

 of microscopic sections, it may be possible to distinguish many of 

 the species by means of such sections of preserved specimens, but 

 that will be a condition possible only in the distant future, and in 

 any case would require much time and labor. 



Exceptional cases are, however, not uncommon in which some 

 prominent feature may be preserved in the alcoholic specimens suf- 

 ficiently well to enable the species to be recognized with certainty. 

 Thus, among the Enopla^ the stylets of the proboscis are frequently 

 characteristic in form or number. The ocelli, often visible in 

 alcoholic specimens, may also be characteristic. In a few cases, 

 even the characteristic colors may be preserved many years in 

 alcohol, and still better in glycerine. I have specimens of Aviphi- 

 porus angxilatns [Stimpsotd), preserved in alcohol twenty years ago, 

 in which the dark purple color of the bod}^ and the characteristic 

 white patches on the sides of the head are still very distinct. These 

 specimens have, however, been kept in dark drawers; those that 

 were exposed to light faded many years ago. 



In consequence of the difficulty or impossibility of identifying 

 alcoholic specimens, T have, in this article, made very little use of a 



