619] INVERTEBRATE ANIMALS OF VINEYARD SOUND, ETC. 325 



anteriorly, narrowing to the end. Collar broad, with a nearly even 

 margin, often somewhat sinuous at the sides, divided above and below, 

 the lobes rounded at the angles. The collar is a little broader below 

 than above. Branchiae long, slender, recurved in expansion, connected 

 by a broad and very thin membrane, continued as thin borders of the 

 branchiae to their tips, which are destitute of pinnae for some distance. 

 Body pale flesh-color, with a darker median line, reddish anteriorly, 

 darker greenish or brownish, posteriorly; branchiae pale yellowish or 

 greenish, each with a flake-white spot near the base outside. Other 

 specimens were greenish gray, with green branchiae. Some were flesh, 

 color, with a bright-red dorsal vessel ; the branchiae flesh-color, without 

 the white spots at the base. 



Length, in extension, about 20 mm ; diameter of body, 1.5 mm . 



Deep water off the mouth of Vineyard Sound ; off Martha's Vineyard, 

 in 21 and 23 fathoms ; off Block Island, in 29 fathoms, sandy mud, 

 abundant. Cosco Bay, 7 to 20 fathoms. 



This species makes slender tubes, covered with fine sand. 



FABRICIA LEIDYI Verrill, sp. nov; (p. 323.) 



Body very small and slender, tapering a little to both ends, in exten- 

 sion considerably exsert from the slender tube ; eleven segments bear 

 fascicles of setae; the segments are about as long as broad, slightly con- 

 stricted at the articulations, with the anterior margin a little promi- 

 nent; anal segment small, tapered to a blunt point, bearing two small, 

 dark ocelli. Branchiae six, subequal, forming three symmetrical pairs, each 

 one with five to seven slender pinnae on each side ; the basal pinnae are 

 about, as long as the main stem, the others successively shorter, so that 

 all reach to about the same level. Tentacles short, thick, bluntly rounded 

 at the end, strongly ciliated. At the base of the branchiae, on each side, 

 is a red, pulsating vesicle, the pulsations alternating in the two; just 

 back of these, on the first segment, are two brown ocelli; a little farther 

 back, and near together, on the dorsal side, are two auditory vesicles, 

 ^ach with a round central corpuscle. The fourth and eleven succeeding 

 segments bear small fascicles of acute, bent setae, about as long as half 

 the diameter of the body ; on the middle segment there are about four 

 or five setae in a fascicle ; on the ninth, three ; on the tenth, two ; on the 

 eleventh, one or two, in the specimens examined. Intestine rather 

 wide, but narrowed at the eighth setigerous segment, and after that 

 slender, bordered by a red blood-vessel on each side. In the fourth 

 setigerous segment there are three globular granulated organs, color, 

 yellowish white, tinged with red by the circulating fluid. 



Length about 3 mm ; diameter about 0.25 mm ; expanse of b ranch ia?, 

 0.8 mm . The specimens measured may be immature. 



New Haven to Vineyard Sound, common at and below low- water 

 mark ; Cisco Bay. 



