196 A. E. Ver rill — Comparisons of Coral i> 'aunoe. 



The entire group is a difficult one, and needs more study, with larger 

 collections. 



Maria Farinha, Pernambuco, No. 4522, type ; and Abrolhos Reefs, 

 No. 4538, type, Yale Mus. (C. F. Hartt). No. 4538 includes three 

 young examples on Mitssa Harttii. 



Siderastreea stellata Ver. See p. 155, and these Trans., i, pp. 352, 353. 



Plate xxx, figures 4. 5. 



Abrolhos Reefs, type, (C. F. Hartt) ; Pernambuco, Mar Grande, 

 Bahia (R. Rathbun). Common everywhere north of Cape Frio, on 

 the reefs, in shallow water, and in tide-pools (C. F. Hartt). 



Var. conferta Ver. See p. 155. 



Plate xxx, figure 5. 

 Abrolhos Reefs, type, (C. F. Hartt) ; occurs with the last. 



Family Poritidae. See p. 158. 



Porites Verrillii Kehb. See p. 161. 



Plate xxxi, figure 5. 



Abrolhos Reefs, type, and Porto Seguro (C. F. Hartt); Pernam 

 buco? (Rathbun). 



Porites Branneri Rath. See p. 162. 



Plate xxxi, figures 6, 6a. 

 Parahyba do Norte and Pernambuco (R. Rathbun). 



Porites astreoides Les. See p. 160. 



Plate xxxi, figs. 4, 4a (typical form). 

 Var. Braziliensis Ver., nov. 



The specimens from Pernambuco are thick incrusting plates, 125 

 to 150 mm broad, with an uneven surface, much infested with bar- 

 nacles. The coral is very porous. The calicles are rather smaller 

 than in the West Indian astreoides, and more crowded than usual 

 in that form. They are mostly polygonal, separated by rather thin 

 and high porous division walls, with a sharp crest, roughly denticu- 

 lated by the tops of the septa, which are lacerately serrulate. Near 

 the margins they are often less crowded, somewhat rounded, and 

 separated by thicker division walls. A considerable number of 

 major calicles, with 24 septa, are scattered over the surface, and 

 some are undergoing fission. 



