424 A. E. VerriU — Marine N^emerteans of JVeir E))</Iatid^ etc. 



as I can see, witli tlie descriptions and figures given by Mclnto.sh 

 and others. 



The character upon which Mcintosh puts the most stress is the 

 greater narrowness of the head, said to be chiefly due to the nar- 

 rower lips of the cephalic slits in the present species, as compared 

 with L. viridis [Gef^serenais). But as the length and breadth of the 

 head and of the margins of the slits are constantly clianging during 

 the motions of the living worms, it is not easy to make sure of such 

 differences. The lighter and brighter red color of the body, and the 

 greater distinctness of tlie ocelli in L. sangiiineKs are also supposed 

 to be cliaracteristic. 



It is found chiefly under stones from half-tide to low-water mark, 

 and at moderate depths (1 to 25 fathoms) on stony and muddy bot- 

 toms. Many specimens are often found living gregariously, curled 

 up together, under one stone, 



LineUS SOCialis (Leidy) VeniU. 



Nemertes socialis Leid}\ Marine Invert. Fauna of Point Jiiditli, R. T., and New 

 Jersey, p. 11 [143J, 1855; Verrill, Invert., Vineyard Sd., etc., p. 334 [G28]. 



Lineus commums Van Beneden (?) ; Verrill, Notice of Recent Addit. to Mar. Invert- 

 Part T. in Proc. National Mns., ii, p. 185, 1870. 



PLATE XXXVII, FIGURES 8, 8(/ ; TLATE XXXVIII, FKiURES 7, 1". 



l>ody very long and slender, subterete, attenuated posteriorly, in 

 full extension abnost linear, up to 8 to 10 inches long, with the di- 

 ameter about ,04 inch. Head very long, flattened, obtuse ; lateral 

 cephalic slits very much elongated. Mouth placed far back from the 

 front of the head. Ocelli very small, often obscured by the dark 

 color of the head, in large specimens four to six or more in a row on 

 each side of the head, the front pair larger than the others and 

 usually separated by a slightly greater interval ; very young ones 

 have only a single pair. Color, above, usually dark olive-green, 

 greenish brown, greenish black, or smoky bi'own, and more rarely 

 reddish brown, the anterior parts often darkest ; indistinct, rather 

 distant, pale transverse lines are often pi-esent, and occasionally 

 there is a darker median dorsal stripe ; front margin of the head 

 paler and slightly translucent ; lower surface of the body usually 

 similar in color to the back but of a ]>aler shade, most frequently 

 dull green or greenish ash. 



Length of large specimens, in extension, 250""", diameter l"'"" to 



cmm 



This is a strictly littoral species. It is common from New Jersey 

 to the Bay of Fiindy. It occurs abundantly and usuallj' gregarious- 



