394 Analytical Synopsis of the Order of Squall. 



The living Heterodontoids are confined to the Pacific Ocean. 

 Four species are now known : the anciently known Port Jackson 

 shark {Heterodontus PJdlippi Blainville) of the Australian seas ; 

 the nearly allied Heterodontus zebra (Gray) of the seas of China 

 and Japan ; the H. franGisci (Gill), recently discovered in the 

 California waters ; and the //. pantherinus (Gray) of the Galla- 

 pagos Islands. 



The Pristiophoroids and Crossorhinoids are also represented 

 by single species, both found in the Chinese and Japanese seas, 

 and the Crossorhinus extends beyond into the Australian. 



The only certainly known representative of the family of 

 Alopecoidge is widely distributed, ranging along the Atlantic 

 and Mediterranean coasts of Europe, at the Cape of Good Hope, 

 and crossing the Atlantic Ocean extends at least along a portion 

 of the eastern coast of North America down to the Caribbean 

 Sea. 



§ ni. 



SYS-TEMATIC ARRANGEMENT. 



Two analytical tables or synopses of the families of the sub- 

 order of Squali are given. The first apparently represents the 

 more natural arrangement and the more probable affinities of 

 the families ; its primary groups are characterized by the posi- 

 tion of the anterior dorsal fin in the first place, and the 

 presence or absence of an anal in the next. In the second, the 

 families are first grouped with regard to the presence or absence 

 of the anal fin, and subdivided in order to show the relations of 

 the groups different from these of the previous synopsis. 



FIRST SYNOPSIS. 



I. Pectoral fins with the anterior margin rising 



directly from the base. Squali. 



