THE OSTEOLOGICAL CHAEAOTERS OF THE FISHES OF 

 THE SUBORDER PERCESOCES. 



By Edwin Ohapin Starks, 



Jssistant Professor in the Department of Biology and Curator of the Museum, University 

 of Washington, Seattle, Washington. 



A study of the skeletons of several representatives of the families 

 Atherinid?e, Mugilidaj, and Sphyrsenidiie, which are grouped together 

 under the suborder Percesoces, reveals the fact that they are not so 

 closely allied to each other as their external similarity would lead one 

 to suppose. 



The specimens from which my observations were made are adult 

 examples of Atherinopsis ealiformensis, Menidiafiotata, Mugil cephalus, 

 and Sphyrcena argentea. 



In examining the crania of these species attention is attracted at 

 once to the fact that in all of them the epiotics are developed into long, 

 thin processes which divide into more or less bristlelike filaments. 



There is little else in purely internal characters whereby to differen- 

 tiate these families as a group from other Acanthopteri. In order to 

 so differentiate them we must turn to the well known external charac- 

 ters — a spinous dorsal in conjunction with the abdominal ventral fins, 

 high pectoral fins, and unarmed opercles. 



If, however, we eliminate the Sphyrteuidiie (which, on account of its 

 fanglike teeth, set in deep sockets, its separate superior pharyngeals 

 of third and fourth branchial arches, its lack of parapophyses on ante- 

 rior vertebrfc, and other characters, we may well be justified in doing) 

 and place it in a separate superfamily coordinate with that in which 

 we place the Mugilidai and Atherinidse, we shall then have remaining 

 a more compact group, notwithstanding- the great difference in number 

 of vertebrpe in the two families of which it is composed. 



In it we find the parapophyses developed on all the abdominal ver- 

 tebrae, the anterior neural spines flattened, wide and thin, the supra- 

 clavicle very small, the superior pharyngeals of each side of the third 

 and fourth branchial arches anchylosed, and the teeth small, not fang- 

 like and set in sockets. 



Proceedings U. S. National Museum, Vol. XXII— No. 1 179. 

 Proc. N. M. vol. xxii 1 



