476 M. Ednioncl Borda2;e on 



a" 



LV. — Phenomena of Autotomy in Phasmid^e belonging to the 

 Genera Monandroptera and Rhapliiderus. By EdmoND 

 BORDAGE *. 



The islands of Eeunion and Mauritius possess two splendid 

 Phasmidffi belonging to the genera Monandroptera and 

 Bhophidervs — M. inuncans, Serville, and B. scahrosus, Serv. 

 {Monandroptera spinigera, Lucas). 



In the ease of the former species the female is apterous and 

 attains a length of 20 centim. by 26 millim. in breadth ; its 

 colour is brown or grass-green. The male, which is greenish 

 grey or green and less clumsy in shape, does not exceed 

 17 centim. in length by 18 millim. in breadth ; it possesses 

 very rudimentary elytra, of the colour of the body, and fairly 

 long wings tinged with pale rose and brown, and having an 

 opaque green margin. 



The dimensions of the specimens of Bhaphiderus scabrosus 

 are considerably less ; the female, which is brown or a magni- 

 ficent grass-green, attains a maximum size of 8*5 centim. in 

 length by 11 millim. in breadth and is devoid of wings. 

 The male, which is likewise apterous, assumes a brown hue 

 and resembles a little twig. It is but 6*5 centim. in length 

 and does not exceed 5 millim. in breadth. 



A few months ago, having succeeded in obtaining a few 

 of these curious Orthoptera, 1 inadvertently left a Monandro- 

 ptera upon a laboratory table. A moment or two later the 

 insect, which was lying upon its back, had lost its two front 

 legs, and I found to ray astonishment that I was confronted 

 with phenomena of autotomy, brought about by two specimens 

 of Plagiolepis }ongip)es^ Forel. (This is an ant which belongs 

 to India, and was introduced a itw years ago by means of 

 ships into Mauritius and Bourbon, where it has invaded the 

 dwellings on the coast.) The severance was produced between 

 the femur and the trochanter t; the cut was as clean as 



* From the ' Comptes Rendus,' t. cxxiv. no. 7 (Feb. lo, 1897), pp. 378- 

 381 : from a separate impression commuuicated by the Author. 



* The trochanter and femur, instead of being united by an articulation 

 allowing of their movement one on the other, are, on the contrary, fused 

 together. It -was only after I had discovered the pheuomeua of auto- 

 tomy that I noticed this fusion, which is, however, indicated by a little 

 groove. After autotomy the portion that still remains attached to the 

 body comprises the coxa, united by the arthrodial membrane to a little 

 ring or cushion, wliich is nothing but the trochanter separated from the 

 femur by the neatest of circular fractures. This fusion, therefore, of the 

 trochanter and thigh, or femur, strongly reminds us of that wliich we 

 observe in the crabs between the basipodite and ischiopodite. 



