174 University of California Publications. [Zoology 



and a point behind the spiracles, a distance equal to one diameter 

 of the eye. In a specimen 6% inches wide the line crosses at a 

 point midway between the edge of the ventrals and a point be- 

 hind the spiracles, a distance equal to three times the diameter of 

 the eye. 



Known from Santa Barbara (Jordan and Gilbert, 1880, p. 

 457) to San Bartolome Bay, Lower California. 



Measukemekts. 



Along median dorsal line: mm. 



From tip of snout to between front of eyes 113 



To between posterior of eyes 20 



To between posterior part of spiracles 32 



To inner angle of pectorals 475 



To tip of ventrals 90 



To tip of spine 25 



To tip of tail 55 



Total length 810 



Along median dorsal line: ^ mm. 



From tip of snout to mouth 120 



To vent 500 



To tip of ventrals 110 



To tip of tail 80 



Interorbital width 120 



Interspii'acle width 110 



Entire width 1400 



Family AeTOBATID.E. 

 23. Aetobatus calif ornicus Gill. 



BAT-FISn. 



(Myliobatus calif ornicus Jordan and Evermann, 1896, I, p. 89.) 

 Yevy abundant on the shallow mnd-fiats. On two occasions in 

 the early summer adult females gave birth to young during their 

 struggles after they had been caught and thrown on the beach. 

 Five were born to one, and six to the other. They resembled the 

 adults in nearly all proportions, except that the tail was longer. 

 They were each about 9 inches in width, and the umbilical cord 

 was wholly absorbed. This ray is found northward to San Fran- 

 cisco (Jordan and Gilbert, 1880, p. 457). 



