90 University of California Publications. [ ZooLocy 
3 mm.; 2 mm. broad in broadest part. Endostyle forming 
considerably less than a right angle with the main axis of the 
‘body. A single short, blunt test process on the anterior half of 
the dorsal edge of the body. 
The above are the characters which seem to distinguish this 
from any hitherto described trophozooid. I am unable to find 
lobes about the branchial orifice, but, owing to the sheht develop- 
ment of these in other species, and to the fact that I have had 
only preserved specimens to examine, and but few of these, I 
assume that they are present but escape observation. 
Although no mantle muscles are present that are not found 
in some, at any rate, of the other described species, they all would 
appear to be particularly well developed here. This is espe- 
cially true of the anterior, a.m., and posterior, p.m. prebranchial 
bands. The sharply cut-off ending of these muscles is deserving 
of notice. The dorsal muscle, d.m., extends back to about the 
middle of the length of the body and terminates, not in a sharp 
cut-off, but in a point by a gradual running out. The stalk, or 
peduncle muscle, is also well developed. The ganglion, g., and 
hypophysis, ly., need no special comment for the present pur- 
pose. The peripharyngeal band, p.ph.b., is very close to the 
branchial orifice, and, from the great size of the orifice, is very 
long. At the great bend of the intestine there occurs a patch 
on the intestinal wall, made up of round bodies, probably large 
cells, gl.b. These are presumably glandular, though they may 
be excretory. Two other well defined patches, of different struc- 
ture, however, from the one just described, occur on the rectal 
portion of the intestine, p. and p’. The nature of these is un- 
known. Many points in the strueture, and particularly the 
physiology, of this generation of Doliolum are in urgent need of 
further study. 
The only specimens of fully grown trophozooids detached from 
their nurse thus far taken in our area were the ones here de- 
scribed. They were secured by Professor H. B. Torrey at San 
Clemente on June 9, 1896. A piece of dorsal process 8 or 10 em. 
long, bearing the trophozooids, was secured. The evidence, there- 
fore, that it belongs to D. tritonis is not direct. I infer that it 
does from the following considerations: It clearly does not belong 
