No. 413.] MORTH-AMERICAN INVERTEBRATES. 393 
each joint. Hydrothece tubular, closely appressed, arranged in rows along 
the pinne, and with plain oblique aperture. 
Gonosome: Gonangia ovate, tapering toward the base, and with a 
tubular orifice. 
Habitat : Shells, stones, etc., generally distributed 
from Grand Manan, Massachusetts Bay, and south- 
ward. 
PLUMULARIDA. 
Synopsis of genera. Modified and 
condensed from Nutting’s Mono- 
graph of the Plumularide. 
ANTENNULARIA. Colony more or 
less arbuscular, stem simple or branch- 
ing, jointed, attached by massive 
hydrorhiza. Branching somewhat 
Fic. 29. — Hydrallmania falcata Linn. verticillate or scattered . hydrothec 
a, hydrothece ; 4, gonangium. 
cup-shaped ; nematophores_ trumpet- 
shaped. Gonangia borne in axils of branches, unilateral. 
MonastT&CHAS. Colony dichotomously branched, stem not fascicled, 
hydrocladia arising from upper sides of branches, otherwise resembling 
Plumularia, from which it differs in the entire absence of cauline hydrothece. 
Gonangia oval in shape and with terminal aperture. 
SCHIZOTRICHA. Colony branching, branches pinnately arranged, hydro- 
cladia often forked. Gonangia borne on stem or hydrocladia. 
CLADOCARPUS. Stem simple or fascicled. Nematophores not trumpet- 
shaped, definitely fixed to hydrothece or branches. Gonangia borne on 
stem or hydrocladia. 
Antennularia Linn. 
1, Antennularia antennina Linn. (FIG. 30). 
Trophosome : Colony growing in dense clusters of upright stems, often 
eight to ten inches high, 
stems simple or sparingly 
branched, obscurely jointed, 
each internode bearing a 
cluster of hydrocladia. Hy- 
drothecz small, cup-shaped, 
and with slightly everted 
margins. 
Gonosome: Gonangia 
ovate, borne singly in axils 
of hydrocladia. Aperture Fic. 30.— Axtennularia antennina Linn. Portion of 
subterminal. stem and hydrocladia (enlarged). (After Nutting.) 
