Analytical /Synopsis of the Order of Squali. 407 



Nasal valves separated by an islliinus or . 

 wide septum. 



Head normally formed and oblong. 



Nasal valves simple, without ciirhi or 

 grooves. Halselurus. 



Nasal valves with cirrhi or grooves. Catnlus.* 



Head transversely oval and swollen be- 

 hind. Cephaloscyllium, 

 Spiracles chiefly beneath the eye. 



Anal fin in advance of second dorsal. Parascylliin^. 



Parascyllium. 

 Anal fin behind second dorsal and contiguous 



to the caudal. Hemiscylliin^. 



Hemiscyllium. 



Fourth and fifth branchial apertures close toge- 

 ther. Chiloscvlliin^. 

 Back not carinated. Chiloscyllium. 

 Back carinated. Synchismus. 

 Caudal fin very long. STEGOSTOMATiNiE. 



Stegostoma. 



Sub-family SCYLLIORHININ^ Gill. 

 Genus Pristiukus Bonaparte, 1838. 

 Galens Rajmesque^ 1810. 



Type Pristiurus melanostomus Bon. 



Genus ScYLLioRHiNUS Blainville, 1816. 

 Scyllinm Cuvier, 1817. 



Type Scylliorhinus canicnla JBlainv. 



Genus Hal.elurus Gill. 

 Type Halaelnrus burgeri Gill. 



Genus Catulus Smith. 

 Poroderma Smith (P. Africaniim Smith). 

 Type Catulus stellaris Smith. 



* The genus Catulus is not a homogenous one, but it is preferred provieionnlly 

 to retain it with the limits here assigned. 



