PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 185 



usually with more or less distiuct brownish. mottUngs along the sides, 

 due to internal organs. The two pairs of ocelli are rather distant, and 

 usually there is a dusky line extending between the two eyes of the 

 same side. On the head, in front of the eyes, there are often tlake- white 

 specks 5 and frequently others occur along the middle of the back. ISot 

 before recorded from the American coast. 



Tetrastemma vittata Vorrill. 



American Journal of Science, vol. vii, ]}. 45, j)!. 7, figs. 3, a, h, 1874 ; Proc. Amer. 



Assoc, for Adv. of Science for 1873, p. 389, pi. 2, figs. 7, 8, 1874. 

 Cosmocepliala (?) cordiceps (Sars, MSS. ), Jensen, Turbellaria ad Litora Norvegite, 



p. 82, tab. viii, figs. 13-16, 1879. 



The species described by Jensen from the coast of Norway agrees so 

 •well, in form and color, with our T. vittata, as to render its identity 

 highly probable. The eyes were not observed by Sars in the l^orwegian 

 specimens, but they are often so obscured by the very dark color of the 

 head, in our darkest examj^les, as to be almost invisible. 



This species was dredged in considerable numbers this season in Cape 

 Cod Bay, 16 to 22 fathoms, mud, by the U. S. Fish Commission. Some 

 of the specimens were 3 inches long. 



Liueus viridis Verrill (== Planaria viridis Fabr.). 



Liiicns Gesserensis M'Intosli. — Ncmcrtes viridis Verrill, Report on Invert, of 

 Vineyard Sd., etc., p. 334 [628]. 



This species is exceedingly abundant on our coast, from the Arctic 

 Ocean to Long Island Sound. It occurs gregariously under stones, be- 

 tween tides, and also at the depth of several fiithoms. The most abund- 

 ant variety is green, varying from dull olive-green to greenish black, 

 the anterior end usually darkest, and the ventral surface paler than the 

 back. The transverse Ught lines are usually indistinct. Length, often 

 150""" or more. 



Var. fusca (^ Planaria ftisca Fabr.). 



This variety occurs like the last, and is usually associated with it. The 

 color varies from pale reddish brown to dark brown and greenish brown. 



Lineus communis Van Beueden. 



This species, accurately described and figured by Van Beueden, is very 

 common, often occurring in large groups under stones and among 

 muscles, on muddy shores, between tides (Eastport, Me., to Long Island 

 Sound). It much resembles the preceding species in form and color, 

 but is more slender, with a more elongated head, the mouth being 

 farther back. The color is usually dark olive-green to greenish black, 

 but varies to brownish and dull reddish. Ocelli black, often rather in- 

 distinct in dark specimens, forming a single lateral row on each side of 

 the head. It is probable that L. socialis (Leidy sp.) is not distiuct from 

 this. 



