208 



BULLETIN 188, UNITED STATES NATIONAL MUSEUM 



Examples up to 6.5 to 7 cm. long show very distinct black vertical 

 blotches or stripes irregularly distributed over the silvery side. In 

 specimens 8 cm. long or more the black markings have usually com- 

 pletely disappeared. In adult males the snout is thickly beset with 

 ttout prickly tubercles ; in adult females the tubercles are less devel- 

 oped, have a rounded top, and may not project above the surface. 

 Full maturity is attained by males at a length of about 11 cm., and 

 many males exhibit lines of pearl organs on the anal rays. Its bril- 

 liant silvery body, extremely wide transverse mouth, and strong, 

 denticulated last simple ray make the fish easily recognizable. 



Among the mountain people of Northern Thailand this fish is 

 everywhere called pla iiviiin^ a name borne by no other species. 



SCAPHOGNATHOPS, new generic name 



Scapho(/natJb02>s, new generic- name to replace Scaphognathus H. M. Smith, pi-e- 

 occupied in reptiles {Scaphognathus Waguer, Sitz. Ber. Akad. Miinchen, vol. 1, 

 pp. 519,531,1861). 



Genotype. — Scaphognathus stejnegeri H. M. Smith. 



SCAPHOGNATHOPS STEJNEGERI (H. M. Smith) 



Figure 36 

 Scaphognathus stejnegeri Smith, 1931a, p. 22, figs. 10, 11 (Mekong). 



Of this strongly marked species only the type specimen is known. 

 It is 22.5 cm. long and was taken in the Mekong, Eastern Thailand, 



Figure 36. — Scaphognathops stejnegeri (H. M. Smith). Drawn by Luang Masya; 

 courtes)^ of the Thailand Government. 



