486 CALIFORNIA ACADEMY OF SCIENCES. II4 



and five bronze bands more oblique than those on dorsal 

 and hence not continuous the whole length of fin; caudal 

 peduncle black, a whitish yellow cross-band behind spine, 

 faint in adult, the anterior margin vertical, the posterior 

 concave; rest of caudal black. Pectoral yellowish; ven- 

 trals dusky, the spine black. 



Adult with the pectoral quite yellow : pale band at base 

 of caudal growing faint with age ; a blue streak along 

 base of dorsal. 



Numerous specimens, the largest about six inches in 

 length, numbered 2899, in the L. S. Jr. Univ. Mus. 



187. Xesurus punctatus (Gill). Cochinito. Plate 

 xlvi. 



Young specimens very abundant in rock pools about 

 Mazatlan, hitherto known only from Cape San Lucas. 

 It was not found by Dr. Gilbert at Mazatlan. Most of 

 our specimens were secured by the use of the fish poison 

 called gervo. By pouring this liquid into the rock pools 

 at low tide this and several other species were obtained 

 in numbers. This gervo or gerbo is the milk}- juice of a 

 tree called hava, abundant in the forests about Mazatlan, 

 and apparently allied to the Strychnos iiitx-zoniica. In 

 rock pools no specimens exceeding two inches in length 

 were found. Several very large specimens were obtained 

 with dynamite about the islands of Creston and Isla Blanca, 

 where the species reaches a length of 16% inches. 



Description of adult: 



Head 4; depth 2; dorsal VII, 26: anal II, 23; snout 

 1^3 in head; eye 5^ : pectoral long as head; ventral 

 \ 2 /l ; caudal 1% ; second dorsal spine 2. 



Body deep, compressed, covered with fine velvet. Cau- 

 dal with three stout compressed blunt spines, with broad 

 bases, the tips turned upward. Some specimens with no 

 other spines; others with many spines, similar in form 



