FRESH-WATER FISHES OF SIAM, OR THAILAND 235 



back, and sides thickly studded with minute pearl organs, which extend 

 to the base of the caudal fin. The essential features are: Depth 3.75, 

 head 4.2, least depth of caudal peduncle 1.5 in its length and less than 

 2 in head, a maxillary barbel less than 0.5 eye, upper lip entire, lower 

 lip papillated; scales in lateral line 37, in transverse line to base of 

 ventral fin 5.5-1-3, in predorsal region 12, around narrowest part of 

 caudal peduncle 16 ; a round black spot as large as eye at base of caudal 

 fin, with a faint dark line extending forward therefrom about half 

 length of body ; median part of each dorsal membrane with a line of 

 dark specks parallel with the rays. 



TYLOGNATHUS ENTMEMA Fowler 



Tylognathus entmema Fowler, 1934a, p. 134, figs. 101, 102 (Bangkok). 



This species is based on a specimen, 6.4 cm. long, from a canal in 

 Bangkok; it is obviously immature. Only the type is known. The 

 body is very deep (3 in standard length), there is a minute maxillary 

 barbel, a round dark spot about the size of the eye occupies the poste- 

 rior part of the caudal peduncle, and there is a narrow dark edge on 

 the dorsal fin. The scales in the lateral line number 33 (35 in the cut) 

 and between the lateral line and the ventral fin there are 5 scales. The 

 specific name {entiiiema^ a notch) has reference to a "slight asymmetri- 

 cal notch" on one side of the rostral fold (also referred to as "the upper 

 jaw edge"). It is believed that, because of its position and the fact 

 that such a feature is not found elsewhere in this genus, the notch is an 

 abnormality or represents an mjury, and is a feature that should not be 

 perpetuated in a specific name. 



TYLOGNATHUS SIAMENSIS de Beaufort 



TylognatJms siamensis de Beaxifort, 1927, p. 5 (Payao Swamp, Menam Chao 

 Phya). 



This was the first species of Tylognathus recorded for Thailand. 

 The specific description by Dr. de Beaufort was based on two speci- 

 mens collected by the writer in 1924, one in Payao Swamp, between 

 Lampang and Chiengrai, and one in a branch of the Menam Chao 

 Phya at Lopburi; the specimens were 13.5 and 11 cm. long. At the 

 time the type was obtained in Payao Swamp, on March 5, 1924, this 

 was one of the most abundant fishes, and many specimens were pre- 

 served. Other specimens agreeing with the original description were 

 taken in the Menam Sak at Dha Luang August 30, 1923 ; in the Menam 

 Chao Phya at Paknam, August 9, 1923, and in the same stream at 

 Bang Pang, November 25, 1923, at Bang Pa-in, December 10, 1924, and 

 a short distance above Bangkok, January 4, 1925. Specimens were 

 obtained also from Bung Borapet, November 19, 1923. A fine series, 



