266 ■ NATURAL HISTOET OP 



17. S. HYALiNA, Linnceus. Plate XXI. fig. 2. 

 Cellepora hyalina [Linn., Fahr., Bosc), C. nitida 



(Fahr.), C. personata (D. Chiaje), Escharina personata 

 (M. Edw.), Berenicea hyalina {Hassall, Flem., Be Bl., 

 G. J.), Lepralia hyalina {W. Thompson, G. J., B. B., 

 Bush, McA), Celleporella hyalina {Gray), Mollia hyalina 

 {8mitt). 



Hab. : Common. 



The colonies formed by this species are of a whitish 

 colour, varying in shade from silvery-white to dull 

 grey. The cells are long and narrow, of an oval shape, 

 with the orifice at the top of each cell. This orifice is 

 rounded, with a sinus in front. The cells are often 

 separated by " punctured spaces.^' There are several 

 variations in the ornamentation of the zooecia. In some 

 forms there are one or more processes on each side of 

 the mouth. In others there is a prominent boss below 

 the orifice. The cells are often marked with minute 

 granulations and indistinct transverse bars. The ooecia 

 are large, globular, with distinct perforations, and are 

 borne on aborted zocecia. There are no spines or 

 avicularia. Though common this is a pretty species, 

 and occurs in roundish patches on algge, &c. 



18. S. VENUSTA, Norman. 



Lepralia venusta [A. M. N.), Gemellipora glabra 

 [Smitt). 



Hab. : Guernsey {A. M. N.). 



This species forms pretty colonies when young, but 

 as the zooecia get old they become dull and coarse. 

 The cells are lozenge-shaped, with rounded punctures. 

 The orifices are circular with a sinus in the lower cir- 

 cumference of each, and below each orifice is a more 

 or less elongated umbo or boss. This species is armed 



