556 BULLETIN 188, UNITED STATES NATIONAL MUSEUM 



Ih. Spines in first dorsal fin to 15 ; ventral fins usually completely united and 

 in fundibnlar form, partly united in young; teetli in upper jaw in 2 rows; 

 scales cycloid, larger, 48 to 60 in lengthwise series Periophthalmodon 



Genus PERIOPHTHALMUS Bloch 



iPeriophthalnms Bloch, in Schneider, Systema ichthyologiae, p. (i3, ISOl. (Type, 

 Periophthalmus papilio Bloch.) 



PERIOPHTHALMUS BARBARUS (Linnaeus) 



GoMiis havMrus Linnaeus, 1766, p. 450 (locality not given). 

 Periophthalmus koelreutcri Sauvaqe, 1883b, p. 151 (Menam Chao Phya). — 

 Johnstone, 1903, p. 295 (Patani, Jhering).— Hora, 1924a, p. 495 (Tale Sap). 

 Periophthalmus iarbarus Fowlek, 1935a, p. 163 (Paknam). 



This species lias a very wide distribution: Japan to China, Philip- 

 pines, Indo-China, Thailand, Malaya, and India, and thence to South 

 Pacific and East Indian islands, West Africa, and Australia. It is for 

 the most part an inhabitant of the muddy, sandy, and rocky shores of 

 bays and estuaries, and of the lower courses of rivers within the in- 

 fluence of the tides. Occasionally in Thailand it is observed in parts 

 of rivers or in canals that are nearly or quite fresh. 



The fish is abundant in all the coastwise districts of the country,, 

 and renders itself conspicuous by regularly coming out of the water 

 and displaying remarkable activity in the air. Dr. Herre (1927,, 

 p. 316) has given this excellent account: 



This extraordinary creature has excited curiosity from time immemorial. Its 

 strange habits, so unfishlilie, its astonishing acrobatic feats of agility, its ability 

 to send its eyes aloft and keep one fixed on the human observer while the other 

 rotates on its conning tower and scans the countryside for prey or foe, its enter- 

 prise in leaving the water and capturing its crustacean and insect food on laud, 

 its habit of leaping along the surface of the water and then taking refuge on 

 land instead of at the bottom of a pool — all these and many other singular traits 

 have caused it to be observed and studied by the ordinary tourist as well as by 

 the fisherman and naturalist. 



In July 1923 the writer made the following note on these gobies as : 

 observed in the Tachin River at Tachalom where, at low tide, a broad 

 bank of soft mud was exposed: The fishes, mostly 10 to 12 cm. long, , 

 were very abundant on the mud flat ; a few were as thick as a man's 

 wrist and about 30 cm. long. From 15 to 20 were in sight at one time, , 

 and were observed at short range from the launch or from an inclined 

 plank walk extending from the water's edge to houses at the top of . 

 the bank. As the gobies emerged from the water and wriggled onto 

 the soft mud, they moved their head from side to side as though 

 sniffing. Many of them paired off and engaged in a comical head-on 

 mock fight, playfully biting at each other and advancing or retreating 

 a few inches at a time, their mouths and eyes filled with soft mud. 

 This may have been a courting exhibition. In the mud near the 



