526 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
branches coming out alternately on opposite sides of the stem. Stem 
and branches bear narrow membranes. Branchlets short and blunt, 
often reduced to mere nodules. Smallest tentacles merely small 
simple papillae. In medium-sized specimens there are about six 
large, six second order, and a dozen third order tentacles in addition 
to the numerous small ones. 
Dorsal lamina broken up into a series of long narrow tapering 
languets. 
Dorsal tubercle C-shaped with irregularly incurved horns; open 
interval to the right. 
Branchial sac with six to eight folds on each side, two of which, 
the second and the last, are so rudimentary as scarcely to deserve 
the name, being represented chiefly by a few closely grouped internal 
longitudinal vessels. Transverse vessels few, of difPerent sizes, but 
not regularly arranged. In the anterior and middle parts of the sac 
they are usually separated by about 12 to 24 of the transversely placed 
stigmata. Small transverse vessels developed only on the folds and 
disappearing in the interspaces are often present about midway 
between the larger ones. 
Stigmata placed (except as noted below) with their long diameter 
transverse to the body axis, forming regular longitudinal rows sepa- 
rated by longitudinal vessels not to be confounded with the internal 
longitudinal vessels w^hich are also present. On the interspaces the 
stigmata are moderately long and narrow, they become shorter and 
the longitudinal rows of them closer together as the summit of a fold 
is approached. On most of the interspaces one of the longitudinal 
vessels separating the rows is broader than the others and is pierced 
by a few longitudinally placed stigmata. 
Internal longitudinal vessels generally corresponding in number to 
the longitudinal rows of stigmata; one vessel crossing all the stigmata 
of a given row. At the summit of the folds, however, the vessels 
become more numerous than the rows of stigmata. Their distribu- 
tion in several moderately large specimens was about as follows: 
mdv. 1 (18) 2 (5) 4 (14) 5 (16) 5 (16) 5 (10) 2 (3) 3 en. 
Digestive tract forming a rather long widely open loop. Stomach 
elongated, thin-walled, but having on the side toward the branchial 
sac a large irregular glandular mass composed of many small short 
blunt-ended caeca. Margin of anus lobed. 
