142 [Assembly 



eight hours, seemed to be in good condition; while specimens of 

 Nereis liinbata Ehlers treated in the same way stopped all move- 

 ments in thirty minutes, and in an hour the blood ceased to circu- 

 late; the latter were taken at a higher station than that in which 

 the former lived, and where they must often have been exposed to 

 the action of brackish water. 



The only place in which this species was found was a few rods 

 above the old wharf, in front of the hotel at Beesley's Point, in 

 coarse sand and gravel, at about half-tide. We looked for them care- 

 fully in many other places, where the conditions seemed to be the 

 same, but without success. 



Sexual Forms. 



Many males and females, apparently adults, were taken, in which 

 no structural changes had occurred except that the eyes had become 

 a little larger ; the anterior pair crescentic ; the posterior oval; the 

 body and feet being swollen by the contained sexual products. 



The color of the female was unchanged ; immature males were 

 bright green ; adult males greenish white. 



This species was first found by Mr. C. L. Culver, at Beaufort, 

 N. C, in the summer of 1877. Mr. Culver was at that time a stu- 

 dent in Union College, and attached to the usual summer zoological 

 expedition of the college. He brought in two specimens with a lot of 

 Nereis limbata Ehlers, taken at low water. The exact station was: 

 not known, and though we searched diligently and frequently for 

 additional specimens, none were found. 



iJ^EREIS TKIDENTATA Th. Sp. 

 PLATE (IV), VII, FIGS. 33-40. 



Head (fig, 33) deeply emarginate in front, and with a well de- 

 fined depression carried back to the middle line ; behind the middle 

 line the sides are convex ; in front of it, strongly concave ; poste- 

 rior margin slightly convex; anterior margin interrupted by the 

 emargination which divides theapes into two bluntly rounded lobes; 

 length to width as two to three. 



Autennte widely separated at origin, conical, length to length of 

 head as two to three. 



Palpi very stout, with long terminal articles. Eyes circular, lateral; 

 anterior pair quite large, situated just back of tlie middle line ; pos- 

 terior about one-half as large as the anterior, and a little within them, 

 very near the posterior margin. 



Buccal segment equal in length to the three following segments 

 taken together ; much wider than the head. 



Tentacular cirri short, tapering but little, arising from stout cylin- 

 drical basal articles ; upper posterior cirrus reaches to the middle 

 of the third segment, or to the front margin of the fourth ; the lower 

 posterior and upper anterior cirri equal, about two-thirds as long a& 



