406 A. E. Yerrill — Marine Nemerteans of Neio England, etc. 



figures. The form and direction of the two pairs of rather indis- 

 tinct, transverse cephalic fossae also varied greatly with the changes 

 in the shape of the head. The two lateral stylet-sacs of the pro- 

 boscis contained three stylets each. 



Color of body, above, pale yellowish green, or pale brown; head 

 with an opaque, flake-white spot in front of the eyes; along the 

 margins of the body the internal organs produce series of brownish, 

 irregular, transverse spots or blotches, varying in depth of color; 

 alternating with these spots, and so interrupting the marginal dark 

 bands, there are small, rounded whitish spots, probably due to the 

 ovaries. 



Tetrastemma elegans Vemii. 



Tetrastemma elegans Verrill, Amer. .Journ. Sci., vol. x, p. 40, 1875. 



? Hedate elegans Girard, Proc. Boston Soc. Nat. Hist., vol, iv, p. 186, 1852. 



Plate x.xxiv, figure 10. 



Body, in extension, longer and more slender than most species of 



the genus, depressed, broadest in the middle, tapering both ways. 



Head ovate, broader than the neck, obtuse or emarginate in front; 



lateral fossa? not very distinct. Ocelli conspicuous, nearly in a 



Fig. 5. Tetrastemma ekyans. Dorsal view. 



square, the front pair rather nearer together than the others. Color 

 above, striped with two broad brown lateral, and a wide median, 

 yellow stripe; the median stripe is clearly defined, clear light yellow 

 and occupies about a fourth of the breadth of the back; it extends 

 to the front of the head, becoming narrow on the neck and then 

 expanding on the middle of the head; a narrow ring of light yellow 

 surrounds the neck, just behind the head; the two stripes of dark 

 brown are well defined, but have irregular margins and are varied 

 in color by paler specks ; lower surface and margins of body and 

 head pale yellow. 



Length 20™™; breadth 1 to l-5'""\ Described from life. 



Noank, Conn., among eel-grass ; Fisher's Island Sound, 2 to S 

 fathoms; Wood's Holl, Mass., on piles of wharf. 



A paler vai'iety occurs in which the lateral bands are lighter 

 brown, interrupted by yellowish spots, and the dorsal stripe is less 

 clearly defined." 



