INVERTEBRATE ANIMALS OF VINEYARD SOUND, ETC. 631 



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 raouth and curving somewhat forward at the 

 sides ) terminal pore small and inconspicuous 5 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 mm to 70 mm ; breadth, 2.5 mm to 3 mm . 



Xew Haven to Vineyard Sound 3 under stones, between tides. 



Polina glutinosa Yerrill, 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 5 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 fossee 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 usually lighter, with a faintly marked dusky or greenish 

 median line. 



Length, 25 mm to 30 mm in extension ; breadth, 1.3 mm to 2 mm . 



Great Egg Harbor to Xew 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 (?) agilis Diesing, Sitzungsberickte der kais, Akad. der Wissenschaf- 

 ten, toI. xlv, p. 232, 1862 (non Monops agilis Sckultze, sp.) 



New Haven ; Point Judith, Rhode Island, at low- water, creeping on 

 2fytilus eclulis (Leidy). 



Acelis crenulata Diesing. 



Op. cit. p. 206. Acmostomum crenulatum Schmarda, Neue wirbell. Th., vol. i, 

 p. 1, 3, PI. 1, fig. 2 (t. Diesing). 



Hoboken, Xew 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 



