COCKROACHES, ETC. 125 



has been found resting on the stems of water-plants, 

 6 or 7 inches below the surface of the water, and 

 when disturbed they dived to the bottom. Mr. 

 Froggatt states that a little black Cricket (Nemobius) 

 in Australia when disturbed often jumps into water 

 and swims along the surface, and I have seen larval 

 Tryxaline Grasshoppers do the same in Borneo. 



None of the above-mentioned insects are specially 

 modified for an aquatic life, though perhaps we may look 

 on the Australian Tetrigine as being on the high road 

 to becoming a truly aquatic insect. There are, how- 

 ever, one or two Orthoptera that are endowed with 

 structures fitting them for life in or on water. Such 

 are the little Tetrigince belonging to the genus Scelimena 

 found in India, Ceylon, and the Malayan region. 

 Dr. G. B. Longstaff caught some specimens of Scelimena 

 logani in a rapidly running river at Dambulla in 

 Ceylon, 2 and has kindly supplied me with the following 

 note : " Most of the specimens were seen on the rocks 

 or sand quite close to the water. When at rest they 

 were very cryptic, closely resembling the rock. They 

 were easily frightened, when they would fly 2 or 3 

 yards and settle again. Several were seen in the water, 

 under the surface, swimming by a succession of short 

 jerks, apparently propelling themselves by the hind- 

 legs." On examining the hind-legs of this species it 

 is seen that the end of the shin, or tibia, of the hind- 

 leg and the first joint of the next segment of the leg, 

 the tarsus, are furnished with membranous expansions, 

 thus converting the hind-leg into a very efficient swim- 



1 Australian Insects, Sydney, 1907, p. 48. 



* Butterfly-hunting in Many Lands, London, 1912, PI. IV., 

 fig. ii. See also the figure of a swimming leg on p. 375. 



