408 BULLETIN 188, UNITED STATES NATIONAL MUSEUM 



9&. Anterior patch of palatine teeth small, oval, placed about midway 

 between jaw teeth and posterior patch, which is parallel with its 

 fellow, elongate pyriform, its anterior end rounded, its posterior 

 end terminating in a long point turned slightly outward ; occipital 



process oval leiotetocephalus 



86. Patches of palatine teeth in transverse series ; teeth villiform. 



10a. Jaw teeth in a long, rather narrow band, which may have a median 



constriction ; palatine teeth in 2 egg-shaped patches on each side, 



the inner patch about half the size of outer ; occipital process large, 



granular, almost circular, touching the broad butterfly-shaped 



basal bone of dorsal spine sagor 



10&. Jaw teeth in a long, rather broad, slightly curved band ; inner pala- 

 tine teeth in a small oval patch which is joined to long outer patch 

 curved downward and outward ; occipital process long, triangular, 

 its truncate posterior side reaching the crescentic basal bone of 



dorsal spine stormii 



Ic. Palatine teeth in 3 groups on each side, each group having a roughly triangular 

 shape, with its base directed anteriorly and formed by 2 small trans- 

 versely united quadrangular patches behind and connected with which 

 is an elongated subtriangular patch, with its rounded apex directed back- 

 ward (genus Netuma Bleeker) thalassinus 



TACHYSURUS MACULATUS (Thnnberg) 



Silurus maculatus Thttnbeeg, 1792, p. 31 (Japan) , 



Arius maculatus Weber and de Bka.tjfort, 1913, vol. 2, p. 284 (Siam). — ^Hoea, 



1924a, p. 467 (Tale Sap). 

 Tachysurus maculatus Fowlee, 1935a, p. 100 (Bangkok, Sriracha). 



This species, of wide range (Indo-Australian Archipelago, Philip- 

 pines, China, and probably India), is abundant in Thailand and it is 

 known from all parts of the Gulf of Siam as well as from the outer 

 and inner lakes of the Tale Sap, and the Tapi, Chao Phya, Bangpa- 

 kong, and Chantabun Rivers. Four specimens taken July 2, 1923, 

 November 10, 1923, and August 16, 1924, from the Bangpakong and 

 Chao Phya Rivers, two being males with oral eggs, differ from typical 

 T. maculatus in having a shorter head, shorter band of teeth in upper 

 jaw, smaller eye, more acute humeral process, and longer dorsal and 

 pectoral spines. 



The species reaches a length of 40 cm., but in Thailand the largest 

 examples observed have been 30 cm. Full maturity is attained in both 

 males and females 16 cm. long. 



An unusually large number of vernacular names is borne by this 

 fish in different parts of its range in Thailand, some of them shared 

 with related species, some peculiar to it. In the Chantabun River, 

 where the fish abounds and large quantities of its eggs are marketed 

 at the town of Chantabun, the names in use are pla kot, pla hot kokaso, 

 pla kot tale {tale = sesi)^ and pla kot na nu {na ?iw=mouse face). In 



