Description of a New Ser hilar iadce. 147 
ing isolated descriptions of five new Sertulariadaefrom the coast 
of California. 
With one exception, they are all most nearly allied to species 
found on the British coasts, viz. to Sertularia operculata, 
S. filicula, Plumularia falcata and Plumularia cristata ; 
and I may notice that along with them I received the stems 
of a Eudendrium which I cannot distinguish from E. ramo- 
sum of our own coast, although, from the want of the vesicles 
it is impossible to decide whether it is a distinct species or 
not. 
-To secure absolute accuracy in the figures, they have been 
drawn by the aid of the camera lucida. 
1. Sertularia tricusjpidata^ Murr. PL YI. fig. 1. 
Cells inversely pear-shaped and nearly opposite, a single 
one in the axilla of each pinna ; mouth at end of cell, aperture 
obliquely truncate, tricuspid at the outer edge ; middle cusp 
longest. Vesicles unknown. 
The habit of this species is perfectly that of operculata. 
Its cells, however, are broader, shorter, stouter, and less acutely 
conical ; they are not perfectly opposite ; they do not meet 
each other at the base, and are more everted ; they are tri- 
cuspid on the outer lip, the middle cusp being longest, and the 
lateral cusps are nearer it and more reflexed than is the case 
in >S^. operculata, when it has two lateral teeth. 
It grows in tufts from 2 to 3 inches high, flexuose and ser- 
rulated, with polype-cells which are fully as much everted as is 
usually the case in this family, instead of being less so, as is 
the habit of ^S^. operculata. 
There were no vesicles in ray specimens* 
Bay of San Francisco. 
2. Sertularia labrata, Murr. PI. VI. fig. 2. 
Cells nearly opposite, a single one in the axilla of each 
pinna ; mouth at end of cell ; lip distinct, not toothed ; aper- 
ture obliquely truncate. Vesicles not known. 
Like S. filicula in habit. The cells, however, are differently 
shaped, more like those of the last species, but not toothed. 
The lip is distinct. 
