278 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.38. 



KEY TO THE SPECIES OK I'l.K URONICHTH YS. 



a 1 . Origin oi dorsal well below level of snout; at least 9 rays on blind Hide of 



body decurrens. 



a 2 . Origin of dorsal at level of snout, or above; 5 or 6 rays on blind side of body. 



b l . Body ami 6ns uniformly covered with brown spots nearly as large as the pupil; 



no teeth on eyed side of jaws; scales 95 to L08 (Asiatic species) .. . .cornutus. 



//-'. Body and fins not uniformly covered with brown spots (American species). 



c 1 . Lnterorbital ridge high and knife-like, ending behind in a sharp spine at leasl 



1 diameter of the pupil above the surrounding level <>t' the head; anterior 



bony tubercle overhanging mouth; no teeth on eyed side of jaws. .verticalis. 



<•'-'. lnterorbital ridge not so high or sharp as described above; anterior I y 



tubercle not anterior to mouth; minute teeth on eyed side of mandible. 



d l . Scales less 1 hail 75 in a series below lateral line; color very dark; broad 



irregular (dutches of dark color with sharp, darker, edges over body and 



fins; caudal peduncle shorl and deep with the tips <>f dorsal and anal rays 



almost, or quite, reaching liases of caudal rays; posterior lnterorbital 



spine very little, or not at all developed nepfa lus. 



(1-. Scales more than 75; color lighter; caudal peduncle longer; posterior inter 

 orbital spine developed. 

 t '. No bony tubercle developed on anterior end of lnterorbital ridge.. co nosus. 

 <*-'. Two bony tubercles developed on anterior end of interorbital ridge. 

 /'. A spot at about middle of lateral line conspicuously ocellated with 

 milk white; scales from 84 to 91; gill rakers below angle of arch 



7 to !) on I In I us . 



/'-'. A spot on middle of lateral line often present, but not conspicuously 

 ocellated with white; scales from 7!) to SI; gill rakers '.) to I I .ritteri. 



PLEURONICHTHYS DECURRENS Jordan and Gilbert. 



This species may bo at once known by the very low origin of (lie 

 dorsal lit) on the blind side of the body, the insertion being below the 

 lower corner of the mouth, and at least nine rays are present on the 

 blind side. 



Head contained from 'A\ to 3§ in length of body without caudal; 

 depth of body I; to 2. Upper orbit, 2\ to 3 in length of head; max- 

 illary 1 to 11; length of caudal peduncle 4 to 5£; its depth 2\ to 3. 

 Number of dorsal rays 71 to 74; anal rays 4(5 to 49; scab's in scries 

 below lateral line «»0 to 95; gill rakers :> or 4 + 7 to 9. 



I lend considerably thicker than body; the snout projecting beyond 

 the dorsal contour, but less abruptly than in other species, leaving 

 a broad concave area above it extending behind the eyes. The 

 interorbital ridge bears a rather sharp spine at cither end; the poste- 

 rior one the larger; pointing backward and downward. In front of 

 the anterior one, before the lower eye, is a small blunt tubercle, and 

 behind the upper eve are two blunt but very prominent ones. The 

 eyes arc large and protruding, and the upper one i-> posterior to the 

 lower. The dentition is stronger than Jisual. There are three rows 

 of teeth ou the blind side of each jaw; one on the cyod side of the 



mandible; none on the eyed side of the premaxillary. 



