14 PEOCEEDINGS or THE GEOLOGICAL SOCIETY. [DcC. 4, 



AsTR^A Pariana, spec, no v.* 



The corallum is massive and rather tall, and its upper surface is 

 flat. The corallites are slender, tall, crowded, and equal. The calices 

 are small, and the fossa is rather deep. The columella presents one 

 rounded process. The septa are in six systems, and there are three 

 cycles ; they are alternately large and small, and the smallest 

 usually unite to the large septa ; they are faintly dentate. The laminae 

 present on their sides sets of granules in horizontal but wavy lines. 

 The endotheca is rare. The diameter of the calices is -^ inch. 



Locality. St. Croix, Trinidad. 



IsASTR^A coNEirsA, spcc. uov. Plate II. fig. 6. 



The corallum is short, and covers much space. The corallites are 

 very irregular in size, and the calices also. The fossa is moderately 

 deep, and presents a false columella. The septa are thick, and 

 unite laterally in sets of three, four, or six. The free margin is 

 faintly dentate. The largest calices have four cycles of septa in six 

 systems ; but usually only three cycles are found in smaller calices. 

 The diameter of^the calices is from y^ ^^ "nr i^ch. 



Locality. St. Croix, Trinidad. 



Stylophora Mns'iJTA, spec, nov.* 



The corallum is encrusting and very small and thin. The calices 

 are circular in outline, and project like small cylinders above the 

 coenenchyma, which separates them. The costae are not in existence, 

 but the cylindrical wall is plain. The septa are six in number, and 

 are stout. The columella is large and styloid. The coenenchyma is 

 lax and plain. There are two calices and the intermediate coenen- 

 chyma in yL inch. 



Locality. St. Croix, Trinidad. 



This species is closely allied to S. raristella, Defrance, sp., of the 

 Faluns. 



5. RemarJcs on the Species. — An analysis of the eighteen species 

 found in the Trinitatian Miocene deposit at St. Croix, gives the 

 following results : — 



1. Species common to the West-Indian and European deposits ... 2 



2. Species common to the St. Croix deposit and other West-Indian 



Miocene deposits 10 



3. Recent species of the West-Indian Coral-fauna 61 ^, 



4. Recent species of the Pacific Coral-fauna 1 J 



5. Species peculiar to the Trinidad Miocene (> 



The genus Heliastroea is very large, and therefore its species are 

 by no means to be readily difierentiated. Nevertheless the five 

 species of the Trinitatian deposit are weU-marked forms, the only 

 close alhance being between H. cylinclrica and H. cave7mosa. H. 

 cylindrica is the oldest species, and may have become modified to 



* The specimens on which these species were founded decayed before they 

 could he drawn, on account of their fragile and chalky nature. 



