FRESH-WATER FISHES OF SIAM, OR THAIL.\ND 557 



wooden walk there were a number of large circular holes into which 

 the gobies plunged when frightened. One of the largest ever to come 

 under the writer's observation went into a hole directly under the 

 walk. Some bright copper coins were displayed and a naked half- 

 grown boy was induced to go after the fish. When half an hour later 

 the writer returned from a visit to the local market, the boy was up 

 to his neck in the hole and was still throwing out mud, but he never 

 reached the fish. Many of the houses on the river's edge had small 

 bamboo traps and the principal catch consisted of gobies of this species 

 which, needless to state, were eaten by the inhabitants. 



The fish shares with PeHophthalmodon schlosseri the vernacular 

 name pla tin. 



Genus PERIOPHTHALMODON Bleeker 



PeHophthalmodon Bleeker (453), Arch. N^rl. Sci. Nat., vol. 9, p. 326, 1874. 

 (Type, Periophthahnus schlosseri Valenciennes.) 



PERIOPHTHALMODON SCHLOSSERI (Pallas) 



GoUus schlosseri Pallas, 1770, pt. 8, p. 5, pi. 1, figs. 1-A (locality not given) 

 Pertophthalmus horneensis Bleekek, 1865 (347), p. 34 (Siam). -Bleeker 1865 



(356), p. 174 (Siam). 

 Periophthahnus schlosseri Bleekek, 1865 (356), p. 175 (Siam).-voN Maetens 



18(6, p. 392 (Siam).-KAKOLi, 1882, p. 166 ( Bangkok ).-Sauvage, 1883b' 



p. 151 (Menam CHiao Phya) .— Hoba, 1923b, p. 179 (Bangkok) 

 Periophthalmus phya Johnstone, 1903, p. 296, pi. 14, fig. 1 (Patani and Jambu 



Rivers, Malay Peninsula). 



The range of this species is from the East coast of India to the Phil- 

 ippines and the East Indies, including Burma, Thailand, and Malaya 

 It IS found on muddy shoi^s in bays, estuaries, rivers, and canals, and 

 m Thailand it goes well upstream into strictly fresh water. 



The largest examples met with in Thailand were 25 cm. long Many 

 were seen up to 20 or 21 cm. 



Great variation in dorsal spines, squamation, and coloration is met 

 with m this species. The number of dorsal spines varies from none to 

 XV; that is, the first dorsal fin may be entirely absent, and a dozen 

 nominal species have been based on this variable feature. 



Giinther (1861, vol. 3, pp. 100, 101) noted specimens from Thailand 

 m the Mouhot collection with 4 or 5 dorsal spines {P. freycineti Cuvier 

 and Valenciennes) and with 13 to 15 dorsal spines (P. tredecimradi- 

 atus Hamilton), both lots apparently taken together, according to 

 Giinther. 



A common size on the banks of canals and rivers exposed at low 

 tide is 6 to 8 cm. long. Such fish find shelter in holes about the 

 diameter of one's thumb in stiff mud. Rapid movement on the mud 

 as m fright, is effected by the flipping of the tail, but for ordinary 

 movement they depend on their pectoral fins, which are moved in 



