222 CALIFORNIA ACADEMY OF SCIENCES. 



one below each eye. Dorsal divided by a deep notch r 

 the anterior part with nine, the posterior with two spines; 

 anal with three. Anterior spines of dorsal each with a 

 pair of antero-lateral grooves. 



The new genus Emmydrichthys is closely related to 

 Synanceia Bloch, differing in having the dorsal divided 

 and with a smaller number of spines, and in the presence 

 of a deep pit or groove below eyes. 



Head 2^ in length, depth 2^. D. IX-II, 7; A. Ill, 

 6; P. 18. Gill opening extending forward almost to be- 

 low mouth, almost as long as depth of body. Head with 

 many pits and irregular protuberances. Eyes situated on 

 the outer sides of a pair of protuberances, the interorbital 

 space very deep and nearly smooth, a large cavity behind 

 each eye and a smaller one below. A small papilla on 

 upper side of eyeball. Jaws equal, fringed with cirri. 

 Anterior nostril tubular. Dorsal fins connected at base. 

 Fin membranes all thick and heavily papillose, greatly 

 thickened around anterior dorsal spines. Eyes midway 

 between snout and origin of dorsal. Middle dorsal spines 

 slightly longest, about equal to distance of first spine from 

 pupil; longest pectoral rays, third and fourth from top, 

 equal to distance of dorsal from tip of lower jaw; anal not 

 so high as soft dorsal; caudal small, rounded, shorter 

 than ventrals; ventrals with two-thirds of inner side grown 

 to body. Color, in alcohol, nearly entirely jet black, the 

 tips of the warty processes on head washed with white, 

 and some minute whitish streaks on under edge of eye. 



This specimen, in color and appearance, bears an as- 

 tonishing resemblance to a lump of black lava.* This 

 is undoubtedly a matter of mimicry, and its native haunt 

 must be among volcanic rocks. 



The type specimen, 9% inches long, was sent to the 



* Hence the name from [iud£o$, a lump of lava. 



