352 PROCEEDINGS : BOSTON SOCIETY NATURAL HISTORY. 
phrascm, and the basal chamber is a mere tube formed by the thick- 
ened chitin and is distinctly a part of the calycle. 
Dimensions. Height of hydrocaulus, 6-10 mm.; length of 
stems, 6-10 mm.; length of hydrotheca, .45 mm.; width at top of 
hydrotheca, .80 mm. ; width of bottom of liydrotheca, .25 mm.; 
length of gonotheca, 2 mm.; greatest width, 1 mm. ; thickness of 
gonotheca, .5 mm. ; number of tentacles, about 26. 
This is one of the most characteristic hydroids of the entire col- 
lection ; the hydra nth, with its thickened, drooping bell, cannot be 
mistaken. There is considerable variation in the thickness of the 
chitin at the base, in some cases the bell being short and almost 
cubical with an immensely thickened diaphragm, while in others it 
is more drawn out and the diaphragm less thick; in short, I have 
found the same variations noted by Hincks, Levinsen, and others. 
I do not agree with Levinsen and Marktanner-Turneretscher in 
regarding C. caliculata , C. Integra , and C. gracilis as inert ly 
modifications of one species. In addition to the difference in the 
form of the bell and in annulations below the hydranth, there is 
a very characteristic difference in the gonophores and in the 
diaphragm. The latter in C. caliculata has no shelf of chitin 
projecting inwards from the thickened hydrotheca, whereas ('. 
Integra (?) has such a shelf well developed. The gonophores are 
much more reduced in C. Integra than in C. caliculata and the 
gonothecae are of very different size and shape. Campanularia 
compressa Clarke is very closely allied to the present species, if not 
the same, the difference in hydrothecae being no greater than the 
variations on the same specimens; while in C. caliculata I note the 
same compression of the gonotheca and the same form. 
Habitat. On red algae off Ft. Wilson, Port Townsend, and at 
Bremerton. Common. Previously noted from England (Hincks, 
Allman, etc.); Bergen (Sars); Labrador (Hincks); Messina (Sars); 
Massachusetts (Agassiz); Rovigno (Schneider); Alaska (?) (Clarke). 
12. Campanularia integra MacGillivray. PL 2, figs. 12, 
12a, 12b, 12c, 12d. PI. 6, fig. 12 r. 
Trophosome. Stems longer than in C. caliculata , simple, un- 
branclied, with at least one, sometimes two or three, deeply cut 
rings below the hydrotheca. In some cases the stem is waved 
throughout the entire length, and at times, but not always, it 
is slightly twisted at the base. The hydrothecae are slightly thick¬ 
ened at the base and on the walls. The thickening at the base 
