INVERTEBRATE ANIMALS OF VINEYARD SOUND, ETC. 607 



iridescent beneath ; sides often with dark brown specks ; anterior 

 branchial cirri usually bright orange, with a red central line; lateral ones 

 darker yellow or orange, generally with a central line of bright red, due 

 to the blood-vessels showing through. 



Length up to 150 mm ; diameter, 5 mm to 7 mm ; length of branchial cirri, 

 G0 mm to 100 mm . 



New Haven to Yineyard Sound; low- water to 6 fathoms, in sand and 

 gravel; common. 



CiRRATULUS tenuis Yerrill, sp. nov. (p. 416.) 



Body slender, elongated, strongly annulated. Head conical, de- 

 pressed, acute. The first four rings behind the mouth are longer than 

 the rest, and destitute of appendages. The branchiae and setae com- 

 mence at the fifth segment ; the branchiae form a cluster on each side, 

 and are long and filiform ; farther back And on the middle region there 

 is usually a pair of branchial cirri on each segment, but posteriorly they 

 become distant and irregular. Setae long and slender in each ramus, the 

 upper ones exceeding in length the diameter of the body on the anterior 

 and middle regions, but becoming much shorter posteriorly. In alcohol 

 the integument is iridescent. No eyes were detected. 



Length, 40 mm ; diameter, i.25 mm . 



Vineyard Sound, 6 to 12 fathoms, among compound ascidians ; 23 

 fathoms off Martha's Yineyard. 



Cirrhinereis fragilis Quatrefages. (p. 397.) 



Histoire naturelle des Armeies, vol. i, p. 464. Oirrhatulus fragilis Leidy, op. cit., 

 p. 147 (15), Plate 11, figs. 39-43, 1855. 



Point Judith, Ehode Island, under stones at low water (Leidy). 

 Specimens, apparently of this species, were dredged in Yineyard Sound. 



Naraganseta cor alii Leidy. (p. 494.) 



Marine Invertebrate Fauna of Rhode Island and New Jersey, p. 12 (144), PI. 

 11, figs. 46-48, 1855 ; Quatrefages, op. cit., vol. i, p. 468. 



New Haven ; Watch Hill ; Point Judith ; in Astrangia Dance. 



Our largest specimen had ten pairs of cirri ; the first three pairs orig- 

 inate from one segment, the lowest being stouter and lighter colored 

 than the rest. 



Dodecacerea, species undetermined, (p. 422.) 



A species, belonging apparently to this genus, was dredged off New 

 Haven Harbor, in shallow water, but the specimens are too young for 

 accurate determination. 



Olymenella Yerrill, gen. nov. 



Body elongated, composed of about twenty-two segments exclusive of 

 the cephalic and anal segments. All the segments, except the buccal 

 and three anteanal, setigerous ; they bear fascicles of slender setae above 



