58 PROCEEDINGS OF THE ACADEMY OF [1885. 



Analysis of Species of Batrachus. 

 Common Characters. — Dorsal spines three ; opercle developed 

 as two strong, diverging, subequal spines ; subopercle rather well 

 developed ; branches of subopercular spine parallel, the lower 

 branch much the shorter. No scales on body. Yertebra 10 + 22 ; 

 frontal region not depressed, its median ridge prominent. Inter- 

 orbital long and narrow with a deep groove. Branchiostegals 6. 

 Teeth conical and blunt ; lateral teeth on jaws and palatines in 

 single rows. A large foramen in axil of pectoral fin (in North 

 American species). Head about 2f in length of body ; width of 

 head from 3 to 4 in length of body. D. 111-24 to 28; A. 

 19 to 22. 

 a. Two indistinct rows of pores on sides of body. 



b. A fleshy tentacle between nostrils ; color brownish or dusky 



greenish, mottled with darker and lighter, the dark on 



sides of body in large irregular blotches extending from 



base of dorsal to about § distance to base of anal, and 



more or less covered with small pale spots ; belly and 



chin plain white or yellowish. In specimens from shallow 



water or algae, the brown becomes nearly black and more 



extended, the belly and chin spotted with darker, and top 



of the head has no distinct markings ; in specimens from 



deeper water or from coral sand, the coloration is more 



brownish or 3^ellowish. Soft dorsal with six to nine 



oblique light bands ; anal with five to nine. Caudal and 



pectoral fins with five to seven light cross-bands, these 



formed chiefly from light spots ; ventrals with some dark 



markings. Tau. 9. 



bb. No fleshy tentacle between nostrils ; color whitish or gray, 



everywhere blotched or spotted with brownish yellow and 



black, the black spots on top of head smaller and more 



numerous than on rest of body ; a large black blotch at 



base of spinous dorsal, running up on fin ; three black 



blotches along base of soft dorsal, which do not extend 



half the distance to base of anal. Pectoral with black 



spots which do not form cross-bands. Ventrals with 



more dark markings than in tau. Dorsal, anal and caudal 



marked nearly as in tau. Tau pardus. 9 b. 



aa. Two very prominent rows of pores on sides of body ; teeth 



more numerous than in Batrachus tau. Cirri above eyes 



very large (Cuv. and Val.). Tau cryptocentrus. 9 c. 



