[631] INVERTEBRATE ANIMALS OF VINEYARD SOUND, ETC. 337 
body, obtuse; a slight groove, usually appearing as a whitish line on 
each side, runs obliquely across the ventral and lateral surface of the 
head, diverging from the mouth and curving somewhat forward at the 
sides ; terminal pore small and inconspicuous; mouth, or ventral pore, 
small. Ocelli numerous, arranged as in the figure, but varying some- 
what in number. (See p. 325.) Color dull yellowish, or yellowish white, 
often tinged with deeper yellow or orange anteriorly, with the median 
line lighter ; a reddish internal organ shows through as an elongated 
red spot between the posterior ocelli. 
Length, 50™™ to 70™™ ; breadth, 2.5™™ to 3™™, 
New Haven to Vineyard Sound ; under stones, between tides. 
POLINA GLUTINOSA Verrill, sp. nov. Plate XIX, fig. 97. (p. 324.) 
Body rather slender and elongated in extension, usually broadest in 
the middle and tapering to both ends, but quite versatile in form ; head 
not distinct, usually obtuse ; posterior end narrower, usually obtuse or 
slightly emarginate ; integument soft, secreting a large quantity of mu- 
cus; the lateral organs extend to the head. Ocelli numerous, variable 
in number, usually eight or ten on each side, arranged in three pairs of 
short, oblique, divergent rows, two to four in each; terminal pore of the 
head moderately large ; no lateral fosse could be detected. There ap- 
pears to be a terminal opening at the posterior end. Color dull yellow 
or pale orange yellow, sometimes brighter orange, especially anteriorly ; 
posteriorly usnally lighter, with a faintly marked dusky or greenish 
median line. 
Length, 25™™ to 30™™ in extension ; breadth, 1.3™ to 2™™, 
Great Egg Harbor to New Haven and Vineyard Sound; low-water 
mark to 6 fathoms. 
MONOCELIS AGILIS Leidy. (p. 325.) 
Marine Invert. Fauna of Rhode Island and New Jersey, p. 11 (143), 1855. 
Monops (2) agilis Diesing, Sitzungsberichte der kais, Akad. der Wissenschaf- 
ten, vol. xlv, p. 252, 1862 (non Monops agilis Schultze, sp.) 
New Haven; Point Judith, Rhode Island, at low-water, creeping on 
Mytilus edulis (Leidy). 
ACELIS CRENULATA Diesing. 
Op. cit. p. 206. Acmostomum crenulatum Schmarda, Neue wirbell. Th., vol. i, 
p. 1, 3, Pl. 1, fig. 2 (t. Diesine). 
Hoboken, New Jersey, in brackish water (Schmarda). 
GENUS UNDETERMINED. 
Body very long and slender, almost filiform, slightly flattened, with 
rounded sides; the flat sides are longitudinally striated, the narrower 
rounded sides are marked with numerous short, distinct, separate, trans- 
verse lines or depressions, corresponding to opaque internal organs. In 
one of the smaller specimens one end is acute conical, terminated by a 
