FAMILIES AND GENEEA OF THE MADREPOBAEIA. 



77 



Genus Pleurophyllia, E. de From. 

 Genus Dendrocora, Duncan. 

 Genus Dactylosmilia, d'Orb. 

 Genus Hymenophyllia, Ed. & H. 

 Genus Rhabdophyllia, Ed. & H. 

 Genera absorbed : — 



Aplophyllia, d'Orb. 5 Caulastr^a becomes a sub- 

 genus. 



Tribe I. 



Genus ErsMiLiA, Milne-Edwards ^ Jules Haime, Hist. Nat. 

 des Corall. vol. ii. p. 186 (1857 ; founded 1848) ; amended. 



The colony is csespitose in shape, and the branches are dichoto- 

 mous or trichotomous. The base increases but slightly with age, 

 and the subcylindrical corallites increase in height, multiply fis- 

 siparously, and speedily become separate. The calices are large, 

 somewhat irregular in outline owing to fission, but are generally 

 elliptical. The columella is composed of a lax, broad tissue, and 

 is at the bottom of a deep fossa. The septa are entire at their 

 upper edge, are well developed, thin, narrow, and slightly gra- 

 nular. The costse are subcrestiform near the calices, and may 

 become more or less indistinct towards the base. The endo- 

 theca is moderately developed, and there is a pellicular epitheca, 

 which does not pass far up the colony. 



Distrihution. — Fossil. Antillian Pliocene. — Becent. Caribbean 

 Sea. 



Eusmilia alticostata, Ed. & Hi, has the costse distinct at the base. 



Subgenus Caijlaste^a, Dana, Zoophytes, Wilkes's Explor. Exited. 

 p. 196 (1846). 



Colony csespitose, with the stems straight or twisted, sub- 

 cylindrical. Calices subcircular, deep. Septa unequal, exsert, 

 subentire, rather numerous. The outer surface of the stems 

 striated or denticulate. 



Distribution, — Becent. Pacific, West Indies ? 



The three species included in Caulastrcea, Dana, form a very 

 natural subgenus of Eusmilia. 



Genus Aplosmilia, d'Orhigny, Note sur les Polyp, foss. p. 6 

 (1849), and Milne- Edwards ^ Jules Saime, Hist. Nat. des 

 Corall. vol. ii. p. 189; amended. 

 The colony is csespitose, and the branches are dichotomous or 



