150 CAI.IFORNIA ACADEMY OF SCIENCES. 



Description — The total length is 14^ inches. The 

 body is compressed throughout, but the shoulder girdles 

 are prominent, so that the width of the body at the base 

 of the pectorals is a little more than the greatest height, 

 and 5 in body length. Immediately behind the pecto- 

 rals the width is a little less than the greatest height; 

 between dorsals and on peduncle it is nearly two, and 

 under second dorsal a little more than two in the height 

 at the same points. Abdomen moderately swollen in front 

 of vent. The back rises at an angle of 45° behind the 

 occiput, slopes downw^ard under first dorsal, leaving a 

 hump under its front end, rises in front of second dorsal 

 and slopes downward again under it. Ventral outline 

 nearly straight. 



The breast and the area between ventrals and vent are 

 almost completely occupied by nearly flat, radially striated 

 plates with slightly raised centers and of variable size, with 

 innumerable excessively minute plates scattered among 

 them. Vent surrounded by prickles. The plates of the 

 ventro-lateral series are small, beginning as distinct rows 

 of spinous plates about opposite vent, with an imperfect 

 row of smaller spinous plates between them and the vent 

 on each side, and converging toward the anal. They 

 pass along sides of anal, remain distinct to about the 

 eighth pair of plates behind the anal and unite in a single 

 median plate with a double spine ; from this plate to the 

 cavidal the rows are again distinct, the plates alternating 

 instead of standing opposite each other. The inferior 

 and superior lateral series begin as distinct row's of spin- 

 ous plates about opposite the middle of the spinous dor- 

 sal, diverge to about the front of the second dorsal and 

 converge toward the base of the caudal; the plates are 

 elongated vertically, their spines, rising abruptly from their 

 centers, are strong, thick, blunt, curved. There are about 



