FAMILIES AND GEIiTERA 0"P THE MADREPOEARIA. 107 



Gl-enus Solenaste-SIA, Milne-Edwards Sf Jules Saime, Sist. Nat. 

 des Gorall. vol. ii. p. 495 (1857), altered. 



Colony massive but light, convex above, incrusting or tall, often 

 gibbous, rarely plane. Corallites long or short, united by a well- 

 developed exotbeea, whicb extends beyond the small costse. 

 Calices with free margins, which are usually circular, but some- 

 times unsymmetrical in outline. Columella spongy or feebly 

 developed. Septa thin or stout, imperforate, dentate. Endotheca 

 fairly developed. Gremmation extracalicinal. 



Distribution. — Fossil. Eocene : Europe, Borneo. Oligocene : 

 England. Miocene : Europe and West Indies. Crag : Eng- 

 land (?). — Subfossil. Eed Sea. — Secenf. Eed Sea, Indian Ocean, 

 Singapore, Caribbean Sea. 



Subgenus CrPHASTEiEA, (genus) Milne-Edwards Sf Jules Saime, 

 Hist. Nat. des Gorall. vol. ii. p. 484 (1857). 



The generic characters are as in Solenastrcea, but the septa are 

 cribriform. 



All so-called Solenastrseans with cribriform septa must enter 

 this subgenus, and all the recorded species of the genus, according 

 to Milne-Edwards and Jules Haime. 



Distribution. — Fossil. Miocene: West Indies. — Becent. Eed 

 Sea, Caribbean Sea, Pacific, Australian seas. 



Grenus Plesiaste^a, Milne-Fdwards Sf Jules Saime, Sist. Nat. 

 des Gorall. vol. ii. p. 489, pi. D 7. fig. 5 (1857). 



Colony variable in shape, massive, convex or subplane above, 

 with a naked and costulate common wall. The corallites may 

 have thick or thin walls, be close or distant, and in the first 

 instance may fuse inferiorly, and in the last may have a feeble 

 exotheca between them. Calices shallow, circular and free. Colu- 

 mella spongy. Septa well developed, exsert, denticulate near the 

 calicular edge. Pali well developed and in contract with all the 

 septa which precede those of the last cycle. Endotheca very 

 feebly developed. Costse and exotheca usually well developed. 

 Epitheca absent. Gremmation occurs in the intercalicinal areas. 



Distribution. — Fossil. Eocene : India (Sind). Miocene : 

 Europe, Sind, Asia. — Hecent. Pacific, North-Australian seas, 

 Indian Ocean, Caribbean Sea. 



In the Tertiary deposits of San Domingo are several species of 

 Flesiastrcea-looking corals (Duncan, "West-Indian Corals," Proc. 

 Geol. Soc, Nov. 1863, p. 37 et seq. and pis. h. &v,). There are 



