450 CALIFORNIA ACADEMY OF SCIENCES. 



ANALYSIS OF THE GENERA OF CALLICHTHYID^. 



a. Body with two series of lateral lamiiiEe which overlap along the median 

 line forming a band-like depression; adipose fin spinous; ventral fins 

 inserted below or anterior to the dorsal fin; gill-membranes contlnenl 

 with the skin of the isthmns; teeth, if present, villiform. 

 b. Two iJairs of nuchal plates between occiput and dorsal plate; suture 

 between humeral and coracoid processes extending almost horizontally 

 to the posterior margin of the pectoral armature; a large opening be- 

 tween coracoid and clavicle below and in front of the pectoral spine, 

 c. Coracoid covered with skin. 



d. Sides of the head with bristles. Scleromystax xcv. 



dd. Sides of the head without bristles; no mental barbels; lower 



jaw with small bands of teeth on the sides; a naked area along 



dorsal and ventral surfaces; suborbital bones concealed; dorsal 



spine rudimentary; caudal rounded. Callichthys xcvi. 



<:c. Coracoid ex^^osed below; coracoid bone joined to the clavicle its 



whole length. 



('. Two barbels at each rictus, none at the symphysis. 

 f. Lower lip without barbels; a naked area along ventral surface; 

 caudal rounded or emargiuate; dorsal spine low and flat; pec- 

 toral spine serrate on inner margin in the young; outer margin 

 and siTrfaces covered with bristles. Hoplosternum xcvii. 



Jf. Lower lip with 4-6 barbels; ventral surface entirely covered; 

 caudal emarginate; dorsal spine high and pointed, subterete; 

 jjectoral spine serrate on inner margin, finer teeth on outer 

 margin. Decapogon xcviii. 



ee. One barbel at each rictus; a pair of long barbels at the symphy. 

 sis; coracoid processes entirelj' covering breast and belly. 



DiANEMA XCIX. 



hh. Occipital with a narrow process extending to dorsal i^late. 



(J. D.I, 10-11; coracoid pi'ocess exiDosed below. Brochis c. 



gg. D. I, 6-8; coracoid process exposed; suture between coracoid and 

 humeral processes extending from the large pectoral pore obliquely 

 downward and backward to the ventral margin of the pectoral 

 armature; dorsal and pectoral s^iines long, pungent, their outer sur- 

 faces smooth. Corydoras ci. 



XCV. Scleromystax. 



Scleromystax Giinther, Cat. Fish. Brit. Miis. v, 225, 

 1864 (barbatus). 



Sides covered with two series of plates meeting along 

 the middle of the sides. Two series of plates between 

 the occipital and the base of the dorsal spine. Head 



