66 BULLETIN 188, UNITED STATES NATIONAL MUSEUM 



MASTOCEMBELUS TAENIAGASTER Fowler 



Mastacemhelus circumcinctiis (non Hora) Fowlee, 1934a, p. 146 (Chantabun). 

 Mastacembelus taeniagaster FowIxEb, 1935a, p. 136, figs. 97-101 (Chantabun). 



A strongly marked species, known from four specimens, 8.9 to 15.3 

 cm. long, from Chantabun, in Southeastern Thailand. 



The species is close to M. circumcinctus but appears to differ in hav- 

 ing fewer rays in the anal fin and in details of coloration; thus, the 

 dark bands on the trunk extend to the spinous dorsal fin (but do not 

 reach that fin in circumcinctus) and the extension of the dark bands 

 across the tail does not reach the edge of the anal fin (while in circuTn- 

 cinctus the dark marks go quite to the free margin of that fin). 



MASTOCEMBELUS ERYTHROTAENIA Blecker 



Mastacemhelus erythrotaenia BlEeker, 1850 (24), p. 6 (Bandjermassing, Bor- 

 neo).— Sauvage, 1881, p. 160 (Siam). 



Macrognathus erythrotaenia Bleekeb, 1865 (347), p. 34 (Sians) ; 1865 (356), p. 

 174 (Siam). 



Bleeker's records are based on a specimen or specimens that he ex- 

 amined in the collection, in the Musee Jardin des Plantes a Paris, made 

 in the Menam Chao Phya by Bocourt. The species was originally 

 described from rivers of Borneo and has since been recorded from 

 Sumatra and Penang. 



The relations of the species are indicated in the preceding key. In 

 addition to lacking the preorbital or infraorbital spine that charac- 

 terizes other local species placed in this group, the markings are 

 striking ; the brown or blackish body has four longitudinal red bands, 

 and the dorsal, caudal, anal, and pectoral fins are black with a red 

 margin. 



MASTOCEMBELUS PAUCISPINIS Fowler 



Mastacemhelus paucispinis Fowler, 1939, p. 75, fig. 23 (waterfall at Trang). 



This species is known from two specimens, 8.6 and 7.7 cm. long, 

 taken on October 13, 1936, from a waterfall stream near Trang, Penin- 

 sular Siam. 



In the paratype the anal and caudal fins are continuous, a feature 

 regarded by Fowler as "apparently abnormal"; in the type both the 

 dorsal and anal fins are disconnected with the caudal, as in several 

 Indian species. Associated with this character is the presence of only 

 16 spines in the dorsal fin, a number much less than in any other known 

 species. From head to base of caudal fin there are 18 or 19 dark bands 

 extending obliquely downward and forward, those over the anal fin 

 continued on the fin, those on the trunk falling short of the median 

 ventral line. In each space between the bands there is a narrow dark 

 stripe parallel with the bands. 



