40 



PISCES 



CLASS I 



Fraas, occur in the Lithographic Stone of Bavaria and Wiirtemberg (Nus- 

 plingen) ; and the genus is also represented in the corresponding formation of 

 Cerin, Ain, France. A complete skeleton of S. baumbergensis, von der Marck, 

 is known from the Upper Cretaceous of the Baumberg, Westphalia ; and more 



B 



Fig. 80. 



A, Squatina aiifera, Mlinst. sp. 



Tooth, x 2. Upper Jurassic 

 (Lithographic Stone); Solenhofen. 

 ]>, Squatina fraasi, Probst. 

 Tooth, x 2. Miocene (Molasse); 

 Baltringen. 



Fig. 81. 



Longitudinal section of the tectospon- 

 dylic vertebral column of Squatina 

 angelus, Linn, cli, Notochord ; d, Cal- 

 cified double-cone (basis of centrum) ; 



ir, Intervertebral space; w, Vertebral 

 centra with concentric calcified rings 

 (after Hasse). 



fragmentary remains of S. cranei, Sm. Woodw., occur in the English Chalk. 

 Numerous teeth and vertebrae in the Tertiary. S. Occident alls, East., from the 

 Maryland Miocene. 



Famih 



; 5. 



Pristiophoridae. Giinther. 



Trunk fusiform. Snout much elongated and flattened, without lateral cartilages, 

 but fringed on each border with pointed dermal teeth. Branchial clefts lateral. The 

 two dorsal fins without spines. Upper Cretaceous to Recent. 



Pristiophorus, M. and H. Miocene to Recent. An undescribed form in the 

 Upper Cretaceous of Mount Lebanon (Smith Woodward). 



Family 6. Pristidae. Gunther. Saw-rishes. 



Trunk elongated, slightly depressed. Pectoral fins rather large, 'united with the 

 head, but not extended to the long, depressed, sword-like rostrum, strengthened with 

 lateral cartilages, and armed with a row of large, dermal teeth on each lateral border. 

 Branchial clefts on the ventral surface. Teeth of the mouth minute and obtuse. 

 Upper Cretaceous to Recent. 



Sclerorhynchus, Sm. Woodw. Teeth of rostrum comparatively small and 

 not fixed in sockets. Rostrum thus resembles that of Pristiophorus, but differs 

 from the latter and agrees with Pristis in the great development of a pair of 

 lateral cartilages. S. atavus, Sm. Woodw., known by nearly complete skeletons 

 from Upper Cretaceous, Mount Lebanon. 



Pristis, Latham. Teeth of rostrum peg-like, firmly implanted in sockets of 

 calcified cartilage. Middle Eocene (Bracklesham Beds) to Recent. 



Propristis, Dames. Rostral teeth as in Pristis, but not implanted in 

 cartilage. Upper Eocene ; Birket-el-Qurun, Egypt. 



Family 7. Rhinobatidae. Midler and Henle. 



Trunk depressed, but elongated. Pectoral fins large, connected with the head, but 

 the cartilaginous rays not reaching the end of the somewhat elongated snout. Branchial 

 clefts on the ventral side. Teeth small and obtuse. Tail robust, with two dorsals and 

 a large caudal fin. Upper Jurassic to Recent. 



