I06 CALIFORNIA ACADEMY OF SCIENCES. [Proc. 3D Ser. 



British Marine Polyzoa, it will only be necessary to expand 

 it and to insert the phrase, "or zoarium, in whole or in part, 

 elevated upon a stalk, or a short peduncle," thus: — 



Family ALCYONIDIID^. 



Zooecia more or less closely united, immersed in an expanded and adher- 

 ent gelatinous crust, or forming an erect cylindrical or compressed zoarium; 

 or zoarium, in whole or in part, elevated upon a stalk or short peduncle; 

 orifice closed by the mere invagination of the tentacular sheath; not pro- 

 tected by external labia. 



Genus Alcyonidium Lmnouroux. 



Zoarium immersed or subimmersed; the orifices simple, papillseform. Zoa- 

 rium gelatinous or argillaceous, either crustaceous, erect, or pedunculated. 



Alcyonidium pedunculatum, sp. nov. 



Zoarium composed of a more or less compressed, bag-like portion forming 

 the head, or capitulum, and a short stalk, or peduncle. Capitulum single- 

 layered for the most part, surface smooth, interior filled with a web-like 

 tissue. Peduncle consisting of a solid mass of zocecia more or less radially 

 arranged, and growing from a small disk, by which it is attached to the sub- 

 stratum. 



Genus Ascorhiza Fewkes. 

 Ascorhiza occidentalis Fewkes. 



Zoarium consisting of an oval, single-layered capitulum, borne on the sum- 

 mit of a segmented muscular stalk arising from an incrusting base. Capitulum 

 consisting for the most part of actively functioning zooecia, the lower portion, 

 however, constituting the budding region for the structures which form the 

 stalk. Surface smooth, zooecia packed close together. Stalk composed of 

 muscular plates or myoecia, homologous with zocecia, entirely immersed in a 

 gelatinous matrix. Myoecia radially arranged in irregular rings, or segments, 

 around a central cavity continuous with that in the head, each containing a 

 number of muscle fibres extending longitudinally from one side of the myce- 

 cium to the other. Surface of stalk marked by constrictions corresponding 

 somewhat imperfectly to the myoecial segmentation. Stalk directiy continu- 

 ous with the base, which consists of a single layer of zooecia forming the 

 means of attachment to the substratum. 



University of California, 



Berkeley, California, 



October 19, 1901. 



