420 A. E. Verrlll — Marine Neruerteans of New England^ etc. 



when the creature is engaged in swallowing some annelid nearly or 

 quite as large as itself. 



The color, in life, is variable; the most common variety is dull 

 green, or olive green, varying to dark smoky green or greenish black, 

 dai'kest anteriorly, and with the under surface and caudal portion 

 somewhat paler ; region of the cephalic ganglions and lateral pits 

 usually reddish ; front and margins of head pale or whitish ; on 

 many specimens faint pale transverse lines or rings can be seen, if 

 carefully examined ; at times a row of small whitish spots, corres- 

 ponding to the genital pores, can be seen on each side. Other speci- 

 mens occur, often living with grewn ones, in which the general color 

 of the body is brown, greenish brown, re(hlisij brown, or chiar red 

 with the margins of the head and lower surfaces liesh-color or 

 reddish. 



Some of these forms differ so much in a[>pearance from the com- 

 mon dark green variety that it would be convenient to distinguish 

 them by variety names, using, in this sense, some of the numerous 

 names applied by the early writers when they were supposed to be 

 distinct species, viz : 



Var. oUvaceiis (Johnston). The typical green and olive-colored 

 variety. 



Var. fiiscns. The brown and reddish brown variety. 



Var. rufiis (Rathke). The distinctly red variety. 



Var. obseurus (Desor). The smoky green and blackish variety. 



Specimens intermediate in color l)etween all these are, however, 

 of frequent occurrence. 



The length, in extension, is sometimes 150'"'" to 200""" ; the di- 

 ameter 2""" to 4'"'" ; in contraction the body becomes much shorter 

 and stouter, large specimens often being only 30'"'" or 40'"'" long and 

 4'"™ to 6'"'" broad. 



In alcoholic specimens the body is usually thickened and rounded 

 anteriorly, more slender and somewhat flattened farther back, often 

 acute at the posterior end ; head obtusely rounded or sub-truncate, 

 with a small terminal proboscis-pore and two lateral slits, which are 

 short and extend forward very near to the proboscis-pore. Mouth 

 small and round, situated slightly behind the posterior ends of the 

 lateral slits ; ocelli not apparent. When placed in alcohol the body 

 usually contracts so violently that it breaks up into segments, es- 

 pecially posteriorly, and the proboscis is often completely ejected. 



The extruded proboscis is long, slender toward the base, clavate 

 toward the end, the terminal portion transversely wrinkled. 



