184 A. E. Verrill — Comparisons o/ Coral Eaunce. 



This is not surprising, for various West Indian mollusks and 

 echinoderms, and some gorgonians, etc., are known to occur on the 

 E. African coasts. 



With the Mediterranean fauna there is little resemblance, but the 

 genus Cladocora is found in both faunae. 



The AVest Indian coral-fauna is characterized by a few genera that 

 are not known to occur in the Indo-Pacific fauna, and by others that 

 are comparatively rare in that fauna. But there is no family of 

 corals restricted to the W^est Indies. 



Among the genera peculiar to the West Indies are ColpophyUiu, 

 Dendrogyra, Meandrlna, rest. {^=zPectinia auth.), Eusmillia, iStep/ha- 

 nocoenia, and perhaps the subgenus Isophyllia. 



Among the common genera that are comparatively rare in the 

 Indo-Pacific, the following may be mentioned : Agaricia, Sideras- 

 trcea, Cladocora, Madracis, Ocidina (rest.), Dichocoenia, Orbicella. 



But the West Indian reef-fauna is also characterized by the con- 

 spicuous absence of a large number of genera and even of some large 

 families of corals that are abundant in the Indo-Pacific. 



Among the families that are lacking are the Turbinar Idas, Eupsam- 

 midce, Fungidoi^ (with numerous genera), Pocilloporidm. 



Of the important Indo-Pacific genera that are lacking, the follow- 

 ing are notable : Turblnaria, Astrmopora, Montipora, Alveo2)ora,\ 

 Synarwa, Psammocora, Pavonia, Pachyseris,Eingia, BerpetoUtha, 

 Cryptobacia, Halomitra, Podobacia, Merulina, Hydnophora, Trida- 

 cophylUa,Echinopora,Mycedium (restr.), UlophylUa, Trachyphyll'ia, 

 Galaxea, Euphyllia, Plerogyra, Eavifes = Prionastrcea, Acanthas- 

 trcea, PoeilloporOy. Slylophora (true), Seriatopora, and many others. 



The total absence of the slender-branched, corymbose and caespi- 

 tose species oi Acropora [Madreporo auth.) is one of the most con- 

 spicuous differences between the West Indian and the Indo-Pacific 

 reefs. Such species are exceedingly abundant and varied on the lat- 

 ter, and give to them some of their most striking characteristics. The 

 absence of Pocillopora, which abounds on all the Indo-Pacific reefs, 

 and even in the Panama fauna, is also a striking featui'e of the West 

 Indian reefs. There are, however, a number of genera that are well 

 developed and abundant in both of these great faunal areas. Among 

 these are Porites, Mcpxmdra, Favia, Solenastrma , Mussa, Millipora, 

 and the stout-branched species of Acropora. 



* A few small, simple representatives of this family, from deep water, have 

 been described by Pourtales. 



f Species of Ahieopora have been described as fossils in the later tertiary 

 deposits of some of the islands, biit none are known living in the West Indies. 



