THE CANADIAN ENTOMOLOGIST. 1^1 1) 



mediana and submediana to stiffen the wings in Embidina, would be out of 

 place in Termitina, where the strong horny basal squama served this pur- 

 pose better. Nevertheless in some species such a connection seems to be 

 faintly indicated upon the squama. Some Termitina (Calotermes) have 

 also a small number of transversals below the mediana, and some have 

 ill-defined transversals below the costa before tip. The structure of the 

 membrane of the wings and of the veins is similar in both families, and 

 unlike the structure of all other families. Finally, though the wings 

 of Termitina are considerably longer than the body, and only as long as 

 the body in Embidina (a little longer in Olyntha), there is, considering 

 the wings, no place more natural for the Embidina than near the 

 Termitina. 



The legs are a very striking and abnormal feature among the char- 

 acters of the Embidina ; they are obviously shaped for burrowing by the 

 compressed enlargement of some parts of these limbs. I have compared 

 them with the burrowing legs of insects of other orders, and was rather 

 astonished to find a very great difference in the arrangement, the attach- 

 ment and the development of the fossorial limbs and their joints. I have 

 tried without success to find in the literature some general considerations 

 or descriptions of fossorial limbs. As their shape must be the conse- 

 quence of purely mathematical principles, a general study of these limbs 

 is still an important desideratum. 



The legs of the Embidina are strong, the middle legs always consider- 

 ably less than the other pairs ; all the legs are comparatively long, the fore 

 legs exceeding the head, the hind legs reaching nearly the end of the 

 abdomen, at least longer than two-thirds of it ; the legs of wingless forms 

 are always shorter. All three pairs are equidistant and attached to the 

 end of the respective segments ; but the bases of the fore and middle 

 legs are as far distant from each other as possible, indeed the legs are 

 attached to the sides of the thorax. The hind legs, on the contrary, are 

 approximate one to the other, so that the coxae are very nearly touching 

 the opposite ones, and are longer and broader than the coxge of the two 

 anterior pairs, which are short, cylindrical, a little incurvate. The fore 

 legs have the femur, the tibia and the first article of the tarsus of about 

 equal length and strength, dilated and compressed ; the first article of the 

 tarsus rather more dilated, depressed, incurvated, with a furrow above ; 

 the two other articles short, the first of them more or less thick ; the claws 

 are short, sharp and simple ; between them is no plantula. The middle 



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