504 BULLETIN 188, UNITED STATES NATIONAL MUSEUM 



opposite the base of the pectoral fins, and the isthmus is correspond- 

 ingly broad. Posteriorly to the front of the dorsal fin the body is 

 covered with extremely minute cycloid scales, and the predorsal region 

 and head are naked; a row of large pores surrounds the eye. The 

 dorsal fins are contiguous, the first having 6 spines, the second 16 rays 

 in the type species. The caudal fin is rounded, and one or two of the 

 median rays in each lobe are produced into short filaments. The anal 

 fin is like the second dorsal and has 15 rays. The ventrals are rather 

 long and pointed and consist of a spine and 4 branched rays. The 

 pectorals are of moderate length, with broad base, and contain 16 rays. 

 The possession of only 4 branched rays in the ventral fins separates 

 Herreolus from all the other local eleotrid gobies and associates this 

 genus with a small Oriental group of which Oxi/metopon Bleeker 

 (1861), Orthostovius Kner (1868), and Vireosa Jordan and Snyder 

 (1901) are other members. The single American genus, loglossus 

 (Bean, 1882, Gulf of Mexico), was placed by Jordan and Gilbert 

 (1882) in the subfamily Oxymetopontinae on the basis of 4 branched 

 ventral rays, and the Oriental eleotrids with the same feature of the 

 ventral fins are obviously referable to the same subfamily. The rela- 

 tions of Herreolus with the related Oriental genera are indicated as 

 follows : 



la. Chin with a large flat median barbel, which is followed by several smaller bar- 

 bels; body covered with minute embedded cycloid scales, head naked; 

 teeth in upper jaw in 2 series, the outer consisting of a few fanglike ca- 

 nines, the inner minute and simple and growing close to and between the 

 canines; lower jaw with canines at sides, 2 of them noticeably larger, and 

 minute teeth among the larger ones; outer rays of each caudal lobe pro- 

 longed into filaments; dorsal rays VI-25, anal rays 25, pectoral rays 



21 (Japan) Vireosa 



16. Chin without barbels. 

 2a. Top of head compressed into a scaly keel or crest; body covered with 

 minute deciduous ctenoid scales ; teeth in both jaws in several rows, the 

 outer row with larger teeth ; upper jaw with 4 canine teeth anteriorly, 

 outer row with larger teeth ; upper jaw with 4 canine teeth anterioi'ly, 

 and pointed ; dorsal rays VI-32, anal rays 32, pectoral rays 20 or 21 ( Sea 



of Timor) . Oxynietopon 



2b. Top of head not compressed into a keel or crest. 



3a. Minute ctenoid scales regularly covering entire body and predorsal re- 

 gion to eyes ; fine canine teeth in both jaws and 4 fanglike teeth in mid- 

 dle; caudal fin obtusely rounded, none of the caudal rays produced 

 into filaments; dorsal rays VI-29, anal rays 30, pectoral rays 18 



(Singapore) Orthostomus 



36. Extremely minute embedded cycloid scales covering body to anterior 

 part of first dorsal fin ; no predorsal scales ; teeth in several rows, 

 those in anterior row in lower jaw enlarged ; a median ray in each 

 caudal lobe produced into a filament; dorsal rays VI-16, anal rays 

 15, pectoral rays 16 (Thailand) Herreolus 



