544 BULLETIN 188, UNITED STATES NATIONAL MUSEUM 



it may be noted that Herre (1933) stated that "authors have con- 

 fused Ctenogobms and RMnogohius^ although an examination of the 

 type species will show good generic differences," although Herre (1927, 

 p. 177) had suggested that Rhinogohius was probably a synonym of 

 Cterwgobius. 



In the present treatment it is intended to use the generic name 

 Ctenogohius, with the following specifications: Body covered wdth 

 ctenoid scales of moderate size, becoming cycloid anteriorly ; opercles, 

 preopercles, and cheeks naked; predorsal scales variable but not ex- 

 tending to or between eyes ; teeth pluriserial, outer enlarged, outer row 

 in lower jaw extending only half length of jaw and possibly termi- 

 nating in a curved canine ; tongue rounded, truncate or very slightly 

 emarginate (exceptionally mucronate) ; dorsal rays VI-I, 8 to 13, 

 anal rays I, 7 to 10; ventrals united into a circular disk, with the 

 f renum bilobed, crenate, or nearly entire ; caudal fin rounded, obtusely 

 pointed, or nearly truncate. 



The members of this genus in Thailand are found in salt, brackish, 

 and fresh w^ater. To render complete the account of the known local 

 representation of the genus, it is thought desirable to include several 

 species that are not of a strictly fresh-water habitat. Some of the 

 local species may prove to be improperly included in this genus, but 

 the information now available regarding them does not indicate the 

 propriety of other allocation. 



The following species are recognized from Thailand : 



la. Scales in longitudinal series 43 to 45, in transverse series between origin of 

 second dorsal and anal fins 15 to 17, in predorsal region 18 to 22 ; a black 

 wliite-edged ocellus at upper base of pectoral fin ; a large black spot at upper 



base of caudal rays ocellatus 



1&. Scales in longitudinal series 35 or less, in transverse series 12 or less, in pre- 

 dorsal region none to 10. 

 2a. Scales in longitudinal series 30 to 35, in transverse series 9 to 12. 



3a. Predorsal scales none ; anal rays I, 9 ; second and third dorsal spines 

 elongated in male ; sides of head with no sharply defined round dark 



spots criniger 



3&. Predorsal scales 6 or 7 ; anal rays I, 7 ; dorsal spines not elongated ; sides 



of bead thickly covered with round dark brown spots cephalopardus 



26. Scales in longitudinal series 25 to 28, in transverse series 6 to 11. 



4a. Predorsal scales none to 4; second and third dorsal spines not 

 elongated. 

 5a. Scales in transverse series 6 ; tongue mucronate ; body with 7 to 11 



yellow cross bands cylindriceps 



5&. Scales in transverse series 8 or 9; tongue rounded. 



6o. Body translucent, with 4 or 5 broad black crosis bands ; head with 

 2 broad black cross bands, top of head wholly black or suffused 



with black alcockii 



6&. Body pale brownish, with 5 large ill-defined dark blotches along 

 side ; spinous dorsal with a round black spot nearly as large as 

 eye on basal part of first 2 membranes chiengmaiensis 



