CHONOPHORUS 211 



elongated; the pectorals large, without silky rays above; the 

 ventrals are very well developed, long, broad, and pointed, and 

 form an exceedingly powerful adhesive organ ; the caudal broad, 

 truncate to pointed, and may be shorter or much longer than 

 head. Dorsal VI, 1-10 to 12 ; anal I, 10 or 11 ; branchiostegals 5. 

 A genus of medium-sized to large gobies, abundant in rocky, 

 gravelly, tropical rivers, of wide distribution in the Indo-Pacific 

 and tropical Atlantic regions. One of the species is a very im- 

 portant ipon goby in northern Luzon, and the adult is one of 

 the chief food fishes in the valley of Cagayan River. 

 Key to the Philippine species of Chonophorus. 



a 1 . Sides with eight to twelve dark brown or blackish crossbars; no lines 



from eye to margin of snout. 



6 1 . Ten or twelve narrow crossbars; a small, vertical, dark brown streak 

 on each scale on upper half of body; a broad dark bar from eye 



diagonally behind maxillary C. genivittatus. 



b". Eight or ten broad, crescentic crossbars; scales on upper half with 

 irregular dark spots; a large black spot beneath eye. 



C. lachrymosus. 



a*. Sides without eight to twelve crossbars; two lines from eye to margin 

 of snout. 



c 1 . First dorsal lightly barred; no ocellus C. melanocephalus. 



c 2 . First dorsal spotted with dark brown; a large, black, white-margined 

 ocellus on posterior half C. ocellaris. 



99. CHONOPHORUS GENIVITTATUS (Cuvier and Valenciennes) 



PLATE 16, FIG. 4 



Gobius genivittatus CUVIER and VALENCIENNES, Hist. Nat. Poiss. 12 



(1837) 48; GUNTHER, Cat. Fishes Brit. Mus. 3 (1861) 13; Fische 



der Siidsee 2 (1876) 170, pi. 110, fig. C. 

 Awaous genivittatus FOWLER, Proc. Acad. Nat. Sci. Phila. (1900) 517; 



JORDAN and EVERMANN, Bull. U. S. Fish Comm. 23 (1903) 492 



(fig. 218, after Gunther). 



Dorsal VI, 1-10 or 11; anal I, 10 or 11; there are 50 to 52 

 scales in a longitudinal series, 14 in a transverse series, and 

 16 to 18 before the first dorsal. 



The body elongate and laterally compressed, the large blunt 

 head much wider than trunk; the greatest depth varies from 

 3.5 to 4f times, the head 3.5 times in length; the snout wide, 

 blunt, and very convex in profile, its length 3 times in that of 

 head ; the rather small eyes high up, lateral, their length 4 times 

 in head and 0.75 that of snout; the distance from tip of snout 

 to rear margin of eye equals postorbital length of head ; the 

 interorbital space narrow, its breadth 0.5 to f that of eye; the 

 subterminal, thick-lipped oblique mouth rather small, with very 

 protractile upper lip ; the maxillary may not reach eye or may 



