566 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
Branchial sac with but one fold on each side. This apparently 
represents the first fold; on the left side it is quite close to the median 
dorsal vessel, on the right side it is a little farther removed, an unus- 
ually wide space (15 stigmata) intervening between the median dorsal 
vessel and the first internal longitudinal vessel. Except for this the 
sac is similar on the two sides of the body. This fold bears a total 
of 14 internal longitudinal vessels on the right side in the large spec- 
imen and a little larger number on the left side. In the smaller 
specimens the fold is even better developed and bears more (16 to 20) 
internal longitudinal vessels. Ventral to this fold the internal longi- 
tudinal vessels are for the most part fairly regularly disposed, being 
separated by from two to four stigmata. Traces of the third (perhaps 
also of the second) fold are probably indicated by a slightly closer 
placing of a varying number of vessels in the regions where these folds 
should be. Total number of vessels on one side of the sac varies from 
about 39 to 46 in the several specimens. Transverse vessels of two 
sizes arranged alternately in the dorsal region of the sac. In other 
parts additional vessels of a third order cross without interrupting 
the stigmata. 
The stomach is elongated, bent at an obtuse angle and has a 
comparatively small number (about 16 to IS) rather indistinct 
longitudinal folds. Intestinal loop rather large; margin of anus 
with indistinct lobes. 
Gonads flask-shaped, somewhat curved, with a central ovary and 
small testes of simple form arranged around its border. The sperm 
ducts unite and open on a papilla on the neck of the ovary as usual 
in this group. There are two gonads on the right side and one on 
the left side, all placed in an oblique position with the neck directed 
toward the atrial orifice. The gonad of the left side is situated 
above and anterior to, and close against the bend of the intestinal 
loop. When the ovaries are well developed the testes become 
crowded into the part of the gonad which lies against the mantle, 
their ducts embracing the ovary and uniting to form the common 
sperm duct on the side of the ovary next to the branchial sac. 
The above described specimen is from Station 184 (off Eastern Point 
Light, N. lat. 42° 30' 15", W. long. 70° 38' approximately, 45 fathoms, 
mud). The two smaller specimens are from Station 2506 (N. lat. 
44° 26', W. long. 62° 10', 127 fathoms, dark brown mud). Hartmeyer 
(1912a) describes this species from a specimen from the Skagerrak, 
