144- 



PAL.EOXTOLOGY 



scales ; it has a short dorsal fin opposite the anal, and has 

 two rows of fulcra to the anterior rays of all the fins. The 

 species range from the lias to the chalk ; one species, indeed 

 (Lepidotus Maximiliani), lingers, after the commencement of 

 the tertiary period, in the " calcaire grossier " of Paris. 



In Kothosomus and OpMopsis the fin-fulcra are in a single 

 row, and the dorsal fin is very long. Kotagogus and Propterus 

 have the dorsal fin almost cleft into two. 



Family XT. — Leptolepid^e. 



The Ganoids of this family are homocercal, and have 

 rounded scales. In the type-genus (Leptolcpis, fig. 56), the 



d 



Fig. 56. 

 Leptolepis sprattiformis (Oolite, Solenhofen). 



scales are extremely thin, yet a fine layer of ganoin may be 

 discovered on them. The teeth are minute and en brosse, with 

 two of larger size in front of the mouth. It has not been 

 determined whether the notochord is ossified ; but traces of 

 distinct vertebral bodies appear to the writer to be discernible 

 in some specimens. Species of Leptolepis range from the 

 lias to the calcareous slates of Eichstadt. They are very 

 common in the lithographic slates of Solenhofen and Fap- 

 penheim. 



Family XII.— Macropomidje. 



Genus MACROroMA. — Fine specimens of homocercal ganoid 

 fishes, with rounded scales, sculptured externally, as in fig. 57, 



