Vol. 3] Starks-Morris.— Marine Fishes. 173 



spines along the median dorsal line, bnt no humeral or other 

 spine. A specimen 37 inches in length had a single small spine 

 at the upper end of each humeral arch, and 8 similar spines in 

 front of them, occupying a space as long as spiracle. The width 

 of the disk was equal to its length from tip of snout to end of 

 ventral fins. It is recorded only from San Diego. 



22. Pteroplatea marmorata Cooper. 



THE CALIFORNIA BUTTERFLY RAY. 



(Jordan and Evennann, 1896, I, p. 87.) 



This .sting ray is very common on the warm, shallow tide flats. 

 The following description was drawn from a specimen 22 inches 

 in length. 



Width from vertebral ridge to outer angle of pectoral equal to 

 length of body from front of eyes to posterior edges of pectorals. 

 Distance along anterior margin of disk from tip of snout to outer 

 angle of pectoral equal to distance from tip of snout to posterior 

 end of ventrals. Interorbital space equal to length of snout ; 

 diameter of eye 3i/2 ii^ interorbital space. Width of mouth equal 

 to distance between outer angles of nostrils, and slightly greater 

 than interorbital space. From tip of snout to mouth 3l^ in dis- 

 tance from mouth to vent. Length of ventral from posterior 

 angle of pectoral equal to width of interorbital space. Length of 

 tail equal to length of snout and eye ; sting inserted opposite pos- 

 terior end of ventrals. 



Color in life : Dark brown everywhere, mottled with small 

 light drab spots and reticulated lines. Belly and front of under 

 parts white ; pectorals yellow^, covered with dark reticulations. 

 Under side of tail and claspers and posterior half of ventrals 

 clear warm yellow. 



The outer angle of pectorals moves farther forward with age. 

 In a specimen 4 feet wide, a line drawn between the outer angles 

 of pectorals crosses the median dorsal line at a point midway be- 

 tween the posterior edge of the ventrals and the front of the eyes. 

 In a specimen 22i/^ inches wide, this line falls midway between 

 the edge of the ventrals and the posterior edge of the spiracles. 

 In a specimen 12 inches wide it is midway between the ventrals 



