The Spine-finned Teleostei 391 



as does the extremely rich and varied evolution of genera 

 and species, effected when the algoid, coralloid, and moUus- 

 can banks of the E. Indies were reached. 



It seems premature as yet to attempt any minute mor- 

 phological comparison of the western and eastern species 

 of the family, as local specific or generic modifications seem 

 often to develop, that have only a local signficance. The 

 varied and often brilliant coloration also, that has largely 

 been used in distinguishing the species is of rather variable 

 and uncertain application. 



The Scaridae are alone explicable morphologically in 

 terms of the more ancestral Labridae, as the latter are of 

 the Pomacentridae. The family is made up of 7 or 8 

 genera, and close on 100 species, all of marine habitat. 

 They represent the end members also of a structural series 

 that has undergone extreme specialization In mouth struc- 

 ture and fin-development, to a degree that becomes a pre- 

 carious heritage. The three genera that are most abundant 

 in species, and most suggestive in distribution, are Scarus, 

 Calliodon,, and Pseudoscarus. Scarus consists of about a 

 dozen species. Three of these surround Cuba, Jamaica, 

 Trinidad and other W. Indian Isles, 2 occur in the Carib- 

 bean sea, 3 are more or less continuous from Jamaica to 

 Bahia, one extends across the Atlantic to the Mediterran- 

 ean, while one is met with in the Madeira and Canary Isles, 

 but also extends to the Mediterranean. The species of 

 CalVwdon may be said to live as the poles apart. For 

 while 2 extend from San Domingo to Trinidad and Bahia, 

 6 inhabit the eastern Archipelago, and i of these passes 

 up to southern Japanese seas. But the presence of one in 

 the Red Sea is proof that many connecting species have 

 been swept out of existence since the time of the Miocene. 



The largest genus Pseudoscarus is made up of 6^^ species, 

 4 of which occur round Cuba and Jamaica, 4 are Caribbean, 

 I is from the Sandwich Islands, i Is N. E. Brazilian, 2 ex- 

 tend from Mozambique to Mauritius, one Is peculiar to 

 Mauritius, 4 to the Red Sea, 2 extend from the Red Sea and 

 Mauritius to Java and Celebes, 8 are peculiar to the coasts 

 of Java, 10 are distributed more or less amongst the E. 



