504 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
the large transverse vessels may be more numerous, through the 
development of others which do not originate from the median dorsal 
vessel. Midway between these large vessels there are vessels of a 
third order, but these are delicate except on the folds and near the 
endostyle where they become stouter. 
Between each two large vessels (first or second order) there is a 
single large infundibulum on each fold. It divides more or less com- 
pletely into anterior and posterior cones separated by a vessel of the 
third order. Stigmata between and on the basal portion of the 
infundibula long and often exceeding in width the vessels separating 
them; this makes the sac very delicate, a condition which is to some 
extent compensated for by slender vessels radially arranged on the 
walls of the infundibula, crossing without interrupting the stigmata. 
There are but few straight stigmata; most of them are arranged in a 
concentric manner extending half or quarter way around the infundi- 
bula. On the upper portion of the latter the stigmata become narrow 
and are irregularly arranged in curves and small spirals in marked 
contrast to their regular arrangement on the basal portions. Dorsal 
to the first fold, and ventral to the last fold, the stigmata are also 
irregularly arranged and curved. 
Stomach wall with a few shallow widely separated folds in addition 
to numerous small convoluted glandular folds which completely 
occupy most of the surface of its cardiac portion and form a fairly 
extensive secreting organ of a green color. The intestine forms a 
loop whose branches are rather widely separated for some distance 
from the reflected end, which owing to the bending of the whole loop 
is turned upward (dorsally). The margin of the anus is apparently 
plain or nearly so. 
Kidney large, somewhat narrowed toward the ends, and very slightly 
curved with the concavity dorsal. It lies against the body wall in 
the right ventral region and generally contains one very large concre- 
tion. 
Gonads in the usual position in the concavity dorsal to the intestinal 
loop and dorsal to the kidney. They each consist of an elongated 
tubular ovary (constricted at the end which is directed toward the 
atrial siphon, but not produced sufficiently to make it proper to speak 
of an oviduct) bordered nearly all around by the small pyriform, or 
two- or three-lobed testes. The left ovary has a nearly dorso-ventral 
direction and is often somewhat bent posteriorly at the ventral end; 
