MOLLUSCA. 211 
among the Zoophytes. They are compound animals, many 
individuals united by a compound integument, and arranged 
according to a uniform plan. 
In some cases, there is only one system of individuals in 
the mass, in other cases, there are many similarly arranged 
and contiguous. The tentacular filaments of the branchiz 
appear to be distinct. They are destitute of the intestinal 
rib which occurs in some of the preceding genera. 
1. Branchial Orifice Radiated. 
a. Branchial and anal orifices, with six rays. 
(A.) Body sessile. The angles of the branchial meshes 
furnished with papilla. The thorax, or cavity containing 
the branchiz, cylindrical. The abdomen is inferior, with a 
stalk. Ovarium sessile, and single. 
Genus Drazona.—Body orbicular, with a single system 
of animals disposed in concentric cirles. 
The substance is gelatinous. The ovarium enclosed in 
fold of the intestine. D. violacea of Sav. tab. ii. f. 3. 
Genus Potyzona.—Body polymorphous, with many sys- 
tems disposed subcircularly. 
The body is subcartilaginous. The individuals are dis- 
posed irregularly around the common centre. Savigny 
inadvertently termed this genus Distoma, a name long 
pre-occupied amongst the intestinal worms. The Aleyonium 
rubrum of Plancus, and the Distomus variolosus of Gaert- 
ner, belong to this genus. ‘The last is a native species. 
(B.) Body pedunculated. 
Genus Srem1ma.—Body a solid cone, consisting of a 
single system of many individuals, irregularly disposed, one 
above the other. 
The thorax is short, and hemispherical. The angles of 
the branchial meshes destitute of papilla. The abdomen 
