44 BRITISH CICADJE. 



Prof. Mik, on the other hand, thinks it more 

 probable that Gonotopus is directly parasitic on the Tetti- 

 gidse, — an opinion which I am inclined to endorse.* 



With all due acknowledgment to Prof. Mik, I have 

 reproduced fom' figm-es from his plate relating to the 

 remarkable construction of the fore leg of the 

 apterous female of Gonatopus. This peculiar develop- 

 ment out of the tarsi, of a prehensile apparatus, only 

 obtains in the female. The contrivance is clearly fitted 

 to secure a hold on the limbs of any unfortunate 

 Cicada which may happen to come within the spring 

 of the Gonatopus. The insect in walking does not 

 appear to make use of the tarsus of the fore leg, 

 which is then folded backwards. One of the claws 

 of the tarsus of each front leg is lengthened into 

 a peculiar sword-like process, and the other claw is 

 developed into a flattened spoon-like plate, with two 

 strong teeth, and short bristles like a comb : these 

 parts are so jointed to the foot that they can be 

 closed one upon the other, after the character of a 

 pair of shears or a vice ; the insect can thus secure 

 itself firmly to the hairs of any unfortunate Cicada 

 on which it leaps. 



There are several species of Gonatopus in which the 

 claws are slightly differentiated from the apparatus 

 above described, but they all seem to be predatory upon 

 CicadsB or small insects of a like kind. On Plate E 

 will be found a drawing of Gonatopus formicarius, and 

 also a winged male of the allied form of Aphelopus. 



Mr. Edward Parfitt, of Exeter, noted a black 

 parasite infesting Jassus {TJiamnotettix) subfusculus, and 

 also Acocephalus {Strongijloccphalus) agrestis. The latter 

 insect was kept on grasses; when eventually the para- 

 site burst open the black case, which he considered to 

 be the hardened skin of the larva, previously attached 

 to the host. He likewise observed the case to open 

 into two parts, and thus " to allow the pupa to drop 



* See Dr. Josef Mik on Gonatojjus pilosus (' "Wiener Entomologische 

 Zcitiiug,' Wieu, 1882). 



