384 THE AMERICAN NATURALIST. [Vor. XXXV. 
3, C. volubilis Linn. 
Trophosome: Stems usually simple, long and somewhat twisted. Hydro- 
thecz deep and sub-tubular, margins with shallow undulations. 
Gonosome: Gonangia flask-shaped, smooth, with an elongate neck 
borne on short pedicels. 
Habitat: Frequently found growing upon other hydroids, usually in 
deep water. Gulf of St. Lawrence, Massachusetts coast, etc. 
4, C. neglecta Alder. 
Trophosome : Stems regularly branched, delicate, filiform, branches pin- 
nate, both stem and branches more or less annulated.  Hydrotheca narrow, 
deep, borne on annulated pedicels and with marginal teeth bimucronate. 
Gonosome ; Gonangia axillary or on short pedicels which are annulated, 
pear-shaped. 
The colony is very minute and inconspicuous. 
5, C. verticillata Linn. 
Trophosome: Colony composed of erect, fascicled stems, irregularly 
branched. Hydrothecz bell-shaped, rather large, deep, with from ten to 
twelve teeth about the margins, 
\ LI 
WW borne on annulated pedicels. 
fg 
y A IPA ^ 
: YB pa Gonosome: Gonangia flask- 
if f shaped, smooth, borne on short 
"c. fg. F 2 è . 
f £2 pedicels and terminating in narrow 
Trophosome : Colony resembling 
in general aspects that of Obelia 
commisuralis, attaining in some 
cases a height of four to six inches. 
J ; orifice. 
N * 6, C. amphora Ag. (FIG. 19). 
A 
E ue M Hydrothece campanulate, with en- 
AN N Em : tire margins, borne on annulated 
Noll a pedicels. 
~ WA Gonosome : Female gonangia elon- — 
gate, somewhat obconical, borne 0? 
Y short annulated pedicels and opening 
by a terminal aperture. Male gonan- 
T E s ad ss gia elongate, oval or spindle-shaped- 
(After Agassin) . ^ pMedusoids more or less degenerate, 
never becoming free ; the male, ac- 
cording to Agassiz, attaining a higher stage of development than the female. 
The embryo escapes from the gonangium as a free-swimming planula. 
