376 



BULLETIN OF THE BUREAU OF FISHERIES. 



of hydrothecae, five to seven being common; hydrothecse slightly flask-shaped but slightly outcun^ed, 

 distal portion free; margin with two blunt teeth; operculum with a large adcauline flap and a smaller 

 abcauline flap. 



Gonosome. — Gonangia borne on the upper sides of branches and branchlets, often forming a row; 

 oblong-obovate in shape, with a tapering collar and circular opening; two small spines may be present 

 on the shoulder. 



Distribution. — Found in the Fish Hawk material, some specimens attached to a crab and some grow- 

 ing on Aglaophcnia rigida. 



J' 



/ ' ^ c 



-Ml ^ 



Fig. 41. — Thujaria/abricii (Levinsen). A and B, portions of colony; C, gonosome. 



There was no gonosome present in the material obtained. The drawing and description were made 

 from a specimen of Prof. Nutting's, obtained at Orca, Alaska, during the Harriman Alaska expedition. 



Family PLUMUURID.E. 



Trophosome. — Hydrothecae sessile, usually adnate by one side, arranged on the upper side of the 

 hydrocladia; nematophores always present. 



Gonosome.— Oonophores producing sporosacs, which are often protected by corbulae. 



Key to the Genera of Plumlxarid.e Found in the Beaufort Region. 



A. Statoplean forms, i. e., those with fixed nematophores which are usuall)' monothalamic. 



a. Gonosome protected by corbulcC, each of which is a modified hydrocladium .... Aglaophenia. 



b. Gonosome provided with protective branchlets, each of which is a modified hydrocladium 



I.ylocarpiis. 



B. Eleutheroplean forms, i. e., those with moveable nematophores which are usually bithalamic. 



a. Gonangia not especially protected. 



I. Hydrocladia pinnately arranged. 



1. Each hydrocladium bears. more than one hydrotheca Plumiilaria. 



2. Each hydrocladium bears a single hydrotheca Monoiheca, 



II. Hydrocladia all springing from upper side of branches Monostmchas. 



b. Gonangia protected by a forking of the hydrocladia Schizotrkha. 



