336 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 



Genus STYLOPOMA Levinsen, 1909 



Levinsen separated this group from Schizoporella and figured but 

 did not describe the genus (1909, Plate 18, fig. 4). Canu and Bassler 

 (1920:359) have established it with Cellepora informata Lonsdale as 

 the genotype. 



The most striking character of the genus is the enormous ovicell 

 which completely covers the zooecial aperture ; the frontal is a tremocyst 

 with small pores and the aperture is semicircular with a narrow, v-shaped 

 sinus. 



Stylopoma informata (Lonsdale), 1845 

 Plate 38, figs, 11-12 



Cellepora informata Lonsdale, 1845 :505. 

 Schizoporella spongites, Osburn, 1914:207. 

 Stylopoma spongites, Canu and Bassler, 1928:91. 

 Stylopoma spongites, Hastings, 1930:721. 

 Stylopoma informata, Osburn, 1940 :424. 



The species has usually been known as spongites but the consensus 

 of opinion now is that the Eschara spongites Pallas, 1766:45, is some- 

 thing else, probably a Schizoporella. 



The zoarium is encrusting, multilaminar and often rises into low 

 irregular frills. The zooecia are of moderate size, about 0.50 mm long 

 by 0.35 mm wide, usually rather regularly quadrangular; frontal a 

 tremocyst with numerous small pores, little convex, smooth (roughened 

 in older stages) ; a low umbonate process proximal to the aperture. The 

 aperture is semicircular, straight on the proximal border, with a narrow 

 v-shaped or sometimes slit-like sinus; the peristome low. 



Avicularia vary in size and form; small triangular ones are often 

 present at one or both sides of the aperture and this form is sometimes 

 found in abundance on the front and even on the surface of the ovicell; 

 larger avicularia, straight or falciform, pointed or spatulate are more 

 rarely found on the front. 



The ovicell is huge, about 0.55 mm wide and long, often as broad 

 as two zooecia, globular, very salient, and encloses both the aperture 

 and the oral avicularia. 



This species is very abundant in the West Indian region, Bermuda 

 Islands to Santos Bay, Brazil. It is apparently rather rare on the Pacific 

 coast of the Americas, where it has been recorded only by Hastings from 

 the Galapagos Islands. 



