396 Analytical Synopsis of the Order of Squali. 



b. Caudal not bent. 



Mouth not terminal ; body subcylindrical. Scylliorhinoidse. 



Mouth terminal ; body depressed. Crossorhinoidae. 

 II. Pectoral fins expanded at base in front and 



separated by a fissure from the neck. Rhin^. 



Mouth terminal. Rhinoidae. 



SECOND SYNOPSIS. 



I. Pectoral fins moderately developed, not 

 notched in front at the base. 

 A. Anal fin present. 



B. Dorsal fins two ; the first in front of the ven- 

 tral s. 



C Branchial apertures entirely before pecto- 

 ral fins. 

 0. Caudal moderately bent, unequal ; tail 



not keeled. 

 h. Caudal nearly lunate, much bent upwards ; 

 tail keeled on each side. 

 GC. Branchial aperture behind above pectoral 

 fin. 



D, Tail keeled on each side ; caudal lunate. 

 DD. Tail not keeled. Caudal unequal, 

 notched near end. 

 E. Dorsal fins unarmed. 



Caudal extremely long; no nictitating 



membrane. 

 Caudal moderately elongated ; eyes 

 with nictitating membrane. 

 Head laterally produced. 

 Head normal. 

 EE. Dorsals each spinigerous in front. 

 BB. Dorsal fins two ; first above or behind ven- 

 trals. 



Squali. 



Odontaspidoidse. 

 Lamnoidae. 



Rhinodontoidse. 



Alopecoidse. 



Cestraciontoida3. 



Galeorhinoidas. 



Heterodontoidaj. 



