FISHES OF WEST COAST OF PERU. 17 



Genus MYLIOBATIS Dumeril. 



16. MYLIOBATIS CALIFORNICUS Gill. 

 RAYO. 



Rhinoptera vespertiUo Gieabd, Proc. Acad. Nat. Sci. Phila., 1856, p. 137; 



Tomales Bay; not Myliohatis vespertiUo Bleeker, also a Myliobatis. 

 Holorhinus vespertiUo Gill, Proc. Acad. Nat. Sci. Phila., 1862, p. 331. 

 MyUobatis caUfornicus Gill, Ann. Lye. Nat. Hist.. New York, 1865, p. 137, 



(after Girard). — Jordan and Evebmann, Fishes North and Mid. Amer., 



vol. 1, 1896, p. 89. — Abbott, Marine Fishes of Peru, Proc. Acad. Nat. Sci. 



Phila., 1899, p.. 331. 



One specimen, field No. 09120, 58 cm. in length from Callao, and 

 one, field No. 09540, 71.5 cm. in length from Paita, bought from 

 fishermen. 



Dimensions of the Paita specimen : 



tnm. 



Length of disk to front of anus 215 



Length of disk to posterior edge of pectorals 250 



Width of disk 445 



Length of tail 465 



Snout 46 



Diameter of eye 13 



Interorbital (bone) 41 



Tip of snout to middle of nasal flap 41 



Tip of snout to anterior gill openings 83 



Distance between anterior gill openings 75 



Distance between posterior gill openings 45 



Length of spiracle 26 



Breadth of distal border of ventrals 55 



Length of fontanel 57 



Greatest width (at anterior end) 25 



Disk not quite twice as broad as long, pectorals slightly convex 

 anteriorly and slightly concave posteriorly ; distal border of ventrals 

 broad and rounded, much broader than in M. asperrimus ; head 

 broad and depressed, snout rather short, shorter than in M. asperri- 

 mus; lateral teeth in 3 to 5 series, median teeth between 4 and 5 times 

 as broad as long; skin smooth. 



Color in alcohol : Dusky brown, a light line originating under mid- 

 dle of spiracle, extending backward along base of pectorals, from this 

 10 or more transverse lines extending across pectorals, these nar- 

 row of bands or lines have well-defined edges but differ so little in col- 

 oration from the ground color as to be easily overlooked; ventral 

 surface light. 



