322 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [616] 
much narrower and more prominent; anteriorly they are very broad. 
Ventral plates rather broad anteriorly, those posterior to the seventh 
or eighth suddenly narrowed. Branchie in three pairs, small, finely 
arborescently divided, the divisions numerous ; posterior pair consider- 
ably smaller than the others. Cephalic lobe with a somewhat prolonged 
frontal border, broadly rounded in front, with an entire margin. Color 
bright red ; tentacles flesh-color. 
Length, 50™™ or more; diameter, 2.5" to 3™™. 
Vineyard Sound; Wood’s Hole on piles of wharves just below low- 
water mark. 
POLYCIRRUS EXIMIUS Verrill. Plate XVI, fig. 85. (p. 320). 
Torquea eximia Leidy, op. cit, p. 14 (146), Plate 11, figs. 51, 52 (seta), 1855. 
In this species there are twenty-five setigerous segments, bearing 
small fascicles of long, slender sete; about seventy posterior segments. 
bear uncini only ; anteriorly the uncini commence on the eighth setig- 
erous segment. There are nine ventral shields, divided by a median 
ventral sulcus. ‘The frontal lobe of the head is large, elongated oval 
or elliptical. The posterior lobe of the mouth is large, rounded. Body 
and tentacles bright blood-red ; the body is often more or less yellowish 
posteriorly. 
Great Egg Harbor to New Haven and Vineyard Sound; low-water 
to 10 fathoms. 
A species of this genus was also dredged in 19 fathoms off Gay 
Head, but its identity with the above is uncertain. Another species, 
remarkable for its brilliant blue phosphorescence, is common in the- 
Bay of Fundy. The P. eximius does not appear to be phosphorescent. 
CHZTOBRANCHUS Verrill, genus nov. 
Allied to Polycirrus and, like the latter, destitute of blood-vessels.. 
Body much elongated, composed of very numerous segments, nearly 
all of which bear fascicles of seta. Segments of the middle region bear: 
simple, or more or less branched, branchial cirri, each of their divisions. 
tipped with slender sete; these cirri are wanting on the anterior and 
posterior segments, the first and last ones being smaller and more simple 
than the rest. The cephalic segment expands into a broad, tentacular 
or frontal lobe, which is rounded or emarginate anteriorly, and often 
more or less scolloped laterally. Tentacles crowded, very numerous, 
long and slender in extension, capable of being distended by the blood, 
as in Polycirrus, &e. 
CHZTOBRANCHUS SANGUINEUS Verrill, sp. nov. (p. 320.) 
Body greatly elongated, much attenuated posteriorly, more or less 
swollen anteriorly, but narrowed toward the head, the thickest portion 
being usually between the tenth and fifteenth segments, The branchial 
cirri commence at about the ninth segment, those of the first pair being” 
short, simple cirri; those on the next segment are once forked ; those on. 
