584 THE AMERICAN NATURALIST. [Vor. XXXV. 
canals, in some cases almost the entire length. Ocelli are present and like 
those in the preceding genus. In color the sensory bulbs are yellowish or 
orange, as are also the gonads. In size mature specimens vary from six 
to ten mm. Hydroid (?). 
Stylactis hooperii Sigerfoos. 
(American Naturalist, vol. xxxiii, p. 801.) 
Bell globular, slightly elongate, about one mm. in long diameter ; radial 
canals four; marginal tentacles eight, very rudimentary, symmetrically dis- 
tributed about the margin; ocelli absent; manubrium large, devoid of oral 
tentacles or lobes; velum narrow; gonads borne in a general mass about 
the manubrium; genital products discharged at once on liberation of the 
medusa, which is quite active for a brief time following its liberation, but 
dies soon after discharge of eggs or sperms. 
Habitat: Colony taken from shell of live snail, //yazassa obsoleta. 
Hydroid, — 72z4. 
Gemmaria cladophora A. Ag. 
Bell hemispherical or subconical, walls rather thick, but varying in dif- 
ferent regions, giving to the bell cavity a shape different from that of the 
external outline; radial canals four; marginal tentacles four, but two rudi- 
mentary, the larger abundantly provided with nematocysts, many of which 
are stalked; tentacular bulbs brownish, with orange pigment at bases; 
manubrium large, with basal conical portion separated by a sharp con- 
striction from the oral portion, which 
has a flaring, quadrangular opening. 
Hydroid (?). 
Corynitis agassizii McCr. 
(Fic. 48). 
(Gemmaria gemmosa McCr.) 
F Bell elongate-hemispherical or RU 
IG. 48. — Corynitis agassizii McCr. "p : * x 
(Adapted from McCrady.) nal tentacles two, 
to tip; radial canals four, with clusters of nematocysts at their marginal 
termini; velum well developed; manubrium of medium size, some at 
conicalin shape. Mature specimens from one to two mm. in diameter. 
Habitat: Taken from shells of Mytilis, etc. Hydroid, — 724. 
