FISHES OF THE ROCKY MOUNTAIN REGION 161 
the high mountains, show closely allied species on the Atlantic and 
Pacific slopes of the Rocky Mountains. 
In the tables and descriptions, D=dorsal fin, A=anal fin; the 
numbers following these indicate the numbers of rays in the fins, thus 
D8 means eight rays in the dorsal fin. A roman numeral, as I, II, etc., 
refers to spines. 
The fin-formulae are written as for instance 5-64—7, which ‘‘means 
that there are five rows of scales between the base of the dorsal fin and 
the lateral line (the scale in the lateral line excluded), 64 oblique trans- 
verse series crossing the lateral line, and 7 horizontal scales between 
the lateral line and the base of the anal or the vent”? (Jordan and Ever- 
mann). 
The teeth-formulae in the Cyprinidae refer to the teeth on the pharyn- 
geal bones. ‘In most cases a principal row of 4 or 5 larger teeth will 
be found, in front of which is a set of one or two smaller ones. The 
two sides are usually, but not always, symmetrical. Thus, ‘teeth 2, 4-5, 
1’ iadicates two rows of teeth on each side, on the one side 4 in the 
principal row and 2 in the lesser; on the other side 5 in the main row 
I in the other” (Jordan and Evermann). 
The Orders are given as in Jordan and Evermann; but they seem 
nearly to correspond with superfamilies in Insecta. 
Crass PISCES (The Fishes) 
Supctass SELACHII (The Sharks and Rays) 
OrDER PLEURACANTHIDES 
The Cladodontide are represented by Cladodus girtyi Hay, in the Coal Measures of 
Colorado. 
OrpER ASTEROSPONDYLI (The Typical Sharks) 
Famity Cochliodontide 
Orthopleurodus novomexicanus St. John & Worth., and Poecilodus springeri St. John & 
Worth., were described in 1883 from the Subcarboniferous of New Mexico. 
Deltodus mercurit Newb., is from the Coal Measures of New Mexico. 
FamILy Heterodontide (The Bullhead Sharks) 
Hybodus polyprion Agassiz, is reported from the Jurassic of Wyoming; it is found also 
in England. 
FAMILy Galeide 
Galeocerdo hartwelli Cope, is from the Niobrara Cretaceous of Colorado. 
