550 BULLETIN 188, UNITED STATES NATIONAL MUSEUM 



type was abnormal, and that the correct number is 6. The genus Thai- 

 gohiella, based largely on this feature, seems therefore to be invalid 

 and becomes a synonym of Brachygobius. 



Numerous specimens, 1 to 2.8 cm. long, from Bangkok were in the 

 collections made by Mr. de Schauensee. Fowler (1937), describing 

 these specimens in detail, considered them identical with Brachygobius 

 xanthozona (Bleeker), made sua a synonym of that species, and noted 

 that "the genotype of Brachygobius was long made known (1849) as 

 Gobius xanthozona Bleeker, from Surabaija, east Java." It may be 

 pointed out, however, that Brachygobius dates from 1874 and that its 

 genotype is Gobius doriae Giinther (1868) from Borneo, as desig- 

 nated by Bleeker in his first description of the genus. Bleeker (1874) 

 made his Gobius xanthozona the type of the genus Hypogymnogobius^ 

 being perhaps influenced by Giinther's statement that Gobius doriae 

 had cycloid scales. As indicated by Koumans (1931), there is no dif- 

 ference between Brachygobius and Hypogymnogobius in this respect, 

 and the latter is a synonym. 



The number of dorsal spines, namely 5, which Fowler ascribes to 

 his Thailand specimens, is incompatible Avith Brachygobius. Fur- 

 thermore, Bleeker, Giinther, and Koumans have given 50 or about 50 

 scales in longitudinal series in xanthozona as against 26 in the type of 

 sua and as stated by Fowler for his specimens of ^'■xanthozona''' from 

 Bangkok. 



An obvious lapsus occurs in Fowler's very useful series of 15 figures 

 of color variation in '■'•xantliozona''' from Thailand in that the dorsal 

 spines are uniformly represented as 4. 



The species described and figured by Herre in Herre and Myers 

 (1937) from Singapore and Johore under the name Brachygobius 

 xanthomelas appears to be the fish now under consideration. This 

 conclusion is reached after an examination and comparison of the 

 paratypes of Brachygobius xanthomelas in the U. S. National 

 ]\Iuseum. 



The presence of scales on the opercles in Brachygobius seems vari- 

 able. In his description of Gobius doriae., Giinther (1868) mentioned 

 "a few scales on the hind part of the gill-cover," but Bleeker, in his 

 definition of Brachygobius., made no reference to the matter, and in 

 his definition of Hypogymnogobius specified no scales on the head. 

 In the noteworthy paper by Koumans (1931) , Brachygobius is defined 

 as having large ctenoid scales on the opercle. Herre (1937) de- 

 scribed and figured Brachygobius xanthomelas as having no scales on 

 the opercle; and finally it may be noted that while Brachygobius sua 

 was originally credited with a scaled opercle, no scales have been found 

 on the opercle in the specimens now in hand. 



