The Spine-finned Teleostei 383 



Serranidae show near affinity, they differ in several im- 

 portant minor yet constant features, such as the two 

 nostrils on each side, the toothed vomerine palate, the 

 distinct pharyngeal bones, and the pseudobranchiae. No 

 other marine family however approaches nearer than it. 

 So we would consider that ^oore's derivation of the 

 African Cichlidae as of other groups of Central African 

 fishes, from a marine ancestry is unwarranted in fact, while 

 the entire question thus raised is fully discussed in a sub- 

 sequent chapter (p. 463). 



Having dealt now with the acanthopterygian families 

 that are wholly freshwater, or whose freshwater anteced- 

 ants seem evident, we can now examine the families that 

 are very largely or wholly marine. These include numerous , 

 genera, and also the large majority of those groups that 

 have become highly modified as coral-strand or pelagic or 

 deep-sea fishes, and which often show brilliant coloration 

 as well as striking morphological modifications. 



One of the largest and apparently the oldest family is 

 the Berycidae, which seems to have arisen from common 

 ancestors with the Aphredoderidae, the Percidae, and the 

 Centrarchidae during early Cretaceous time. As in all of 

 these the head has large mucous cavities, and the pelvic 

 fins are nearly or exactly subpectoral. As in the Salmonidae 

 the anal fin is made up of more than ten — often many — soft 

 rays. But it is as yet impossible to trace the graded series 

 of connecting types that would link theBerycidae with more 

 primitive soft-rayed fishes, or fishes with only a few fin- 

 spines. But if we suppose a type to have existed in Mid- 

 Cretaceous or early upper Cretaceous time that still fre- 

 quented freshwater or had recently passed seaward, such 

 would satisfy required conditions, for the earliest Berycids 

 are in Upper Cretaceous rocks, and even then are evidently 

 marine. The fossil genera and species also so far as known 

 are N. American and Europeo-Mediterranean. 



But even in these the dorsal fin was fairly extended, and 

 showed — as in Acrogaster and Sphenocephalus — 3 to 5 

 dorsal spines in addition to 10- 14 soft rays. The anal fin 

 also possessed 3 spines and 9 - 14 soft rays, while the 

 pelvic fins had i spine and 6 - 8 soft rays, thus being inter- 



