LEPIDOGANOIDEL 163 



notocliordal (fig. 72). The dorsal, d 9 is opposite the ventral, v. 

 One species of Caturus (C. Bucklandi) is from the lias ; but 

 the majority, like C. furcatus, are from the lithographic slates 

 of Solenhofen. The most recent known species (C. similis) is 

 from the chalk of Kent. 



PacJiycormus, Saurostomus, Sauropsis, Thrissonotus, and 



v- 



Fig. 72. 

 Caturus furcatus (Oolite, Solenhofen) . 



Eugnathus, are liassic genera of the present family. It is 

 deemed by some Palaeontologists to be represented at the 

 present day by the North American genus Lepidosteus ; but 

 in this fish the notochord is converted into bony vertebral 

 bodies, united by ball-and-socket joints, and the tail is hetero- 

 cercal. 



Family VIII. — Pycnodontes. 



The name of this group of ganoid fishes refers to the blunt 

 rounded form of the greater proportion of the teeth, espe- 

 cially those attached to the palate and hind alveolar part 

 of the lower jaw : the few anterior teeth are small and 

 sub-prehensile ; but the whole dentition bespeaks fishes 

 adapted to feed on small testaceous and crustaceous animals. 

 In the modern " Sea Breams" (Sparoids), with an analogous 

 dentition, the two premaxillaries oppose the two premandi- 

 bulars, but in the extinct Pycnodonts the vomer, as in 

 Anarhichas, opposes its pavement of teeth to that of the tw T o 



