Description of a New Ser hilar ladce. 147 



ing isolated descriptions of five new Ser tulariadae from 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. Tamo- 

 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 tricuspidata, Murr. PL VI. 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 S. 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 my specimens. 



Bay of San Francisco. 



2. Sertularia labrata, Murr. PL 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. 



