LEPID0GAN01DKI 1 43 



below. The oblique inner processes of the scales appear as 

 distinct dermal ossicles decussating the neural spines in the 

 space between the occiput and the dorsal fin (fig. 55). 



The species of Pycnodus abound in the oolitic formations 

 above the lias : the one figured (P. rhombus) is from a cal- 

 careous deposit, so charged with animal remains as to be 

 foetid, at Torre d'Oiiando, near Naples. Species of Pycnodus 

 (P. cretaceous, e. g.) occur in the chalk of Kent ; and one 

 species (P. toliapicus) has left its remains in the eocene clay 

 of Sheppy. Some teeth from German miocene have been 

 referred to this genus ; but at this period, if not at the earlier 

 tertiary one, Pycnodus became extinct. 



Family IX. — Dapedidje. 



Notochordal rhombo-ganoids, with front teeth conical or 

 bifurcate, back teeth obtuse, vertebral column and side 

 scales continued into the upper lobe of an almost sym- 

 metrical tail-fin. 



The type-genus, Dapcdius, is a compressed deep-bodied 

 fish, with a single dorsal, and a single series of fin-fulcra ; the 

 front teeth are commonly notched. All the species are from 

 liassic strata. Amblyurus, with a similar form, and also 

 liassic, has a very narrow anal, and a wide mouth with small 

 pointed teeth. Semionotus and Pholidophorus are long-bodied 

 fishes, the species of which range from the lias upwards to 

 the Purbecks {Pholidophorus ornatus), and to the chalk 

 (Semionotus Bergeri). 



Family X. — Lepidotid^:. 



Homocercal rhombo-ganoids, with obtuse teeth and well ossi- 

 fied vertebra?. 



The type-genus of this family, Lepidotus, is remarkable for 

 the density and polish of its full-sized imbricated rhomboid 



