334 REPORT OF COMMISSIONER OF FISIL AND FISHERIES. [623] 
Carolina (Girard). Newport, Rhode Island, to Beverly, Massachusetts 
(A. Agassiz). In sand between tides. 
A reexamination of living specimens of the southern form will be 
necessary before their identity with the northern one can be positively 
established. Iam unable to separate them with preserved specimens. 
See page 351; also American Journal of Science, ser. 3, vol. v, p. 235.) 
NEMERTES SOCIALIS Leidy. (p. 324.) 
Marine Invert. Fauna of Rhode Island and New Jersey, p. 11 (143), 1855, 
Great Egg Harbor to New Haven and Vineyard Sound. Very com- 
mon under stones, between tides. 
NEMERTES VIRIDIS Diesing. ; 
Sitzungsberichte der kais. Akad. der Wissenschaften, vol. xlv, p. 305, 1862. Pla- 
narid viridis Miiller, Zo61. Dan. Prodromus, 2534, 1776 (t. Fab.) ; Fabricius, Fauna 
Grenlandica, p. 324, 1780. Notospermus viridis Diesing, Syst. Helminth, vol. i, 
p. 260, 1850, Nemertes olivacea Johnston, Mag. of Zoology and Botany, vol. i, 
p. 536, Pl. 13, fig. 1. Borlasia olivacea Johnston, Catalogne British Non-para- 
sitical Worms, p. 21, Pl. 25, fig. 1,1865. Nemertes obscura Desor, Boston Journal 
of Natural History, vol. vi, pp. 1 to 12, Plates 1 and 2, 1843. Polia obscura 
Girard in Stimpson’s Marine Invertebrata of Grand Manan, p. 28, 1853. 
Body very changeable in form; in full extension long and slender, 
sub-terete, tapering toward both ends, the length being sometimes 150™™ 
to 200, while the diameter is 2™™ to 8™™; in contraction the body 
becomes much shorter and stouter, more or less flattened, and obtuse at 
the ends, large specimens often being only 30™ or 40"™ long aud 4™™ to 
5™2 broad. The head is flattened, more or less bluntly rounded, and is 
furnished with a row of small dark ocelli on each side, which vary in 
number and size according to the age, the large specimens often having 
six or eight on each side, while the small ones have but three or four, and 
the very young ones have only a single pair. The lateral fosse of the 
head are long and deep, in the form of slits, and extend well forward to 
near the terminal pore. The latter in some states of contraction appears 
like a slight vertical slit or notch, but at other times appears circular; the 
proboscis is long, slender toward the base, clavate toward the end, the 
terminal portion transversely wrinkled. The ventral opening or mouth 
is gituated opposite to or a little behind the posterior ends of the lateral 
fosse ; it is ordinarily small and elliptical, with a distinct lighter colored 
border, but is capable of great dilation when the creature is engaged in 
swallowing some annelid nearly as large as itself. 
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-trunecate, with a 
small terminal pore and two lateral fosse, which are short and extend 
forward very near to the terminal pore; ventral openin g or mouth 
small and round, situated slightly behind the posterior ends of the lat- 
eral fosse ; ocelli not apparent. The color, when living, is very variable, 
