64 



CALIFORNIA ACADEMY OF SCIENCES, 



coarsely granular in young, the granules becoming finer 

 and more regularly arranged in the adult; opercles 

 smooth; humeral process with radiating lines of granules. 

 Occipital process variable in shape, broader than long, 

 the posterior margin convex; dorsal plate variable 

 in outline, rounded anteriorly, saddle-shaped, either 

 broader than long, or longer than broad; middle of the 

 fontanel above the posterior margin of the eye; the 

 fontanel divided into three by two bony bridges, the 

 middle portion being more than half of its whole length. 

 Sides of head with reticulating mucous canals. No 

 skinny flap connecting the posterior nostrils. 



Eye 2-3 in snout, 6-9 in head, 3-41 in the interocular. 

 Maxillary barbels extending little beyond the base of 

 pectoral, or shorter; mental barbels short. 



Upper jaw little produced; 

 teeth in the jaws rather large, 

 conical; teeth of vomer and pal- 

 atines finely granular, the vo- 

 merine patches separated from 

 each other and from the palatine 

 patches in the young, united and 

 covering almost the entire roof 

 of the mouth in the adult; the 

 inner margins of the palatine 

 patches approximated, some- 

 times a small elliptical patch 

 of teeth between. 

 /^ Gill-membranes forming a 



broad marginal flap across the isthmus. Gill-rakers 

 3-4+7-9. 



Axillary pore minute or wanting; vertical series of 

 pores present. 



Distance of dorsal from tip of snout 2h in the length; 

 the spine lj-l| in the head, granular in front, scarcely 



