ii6 



ARACHNOIDEA. 



CASE network of fine threads of silk, in which they suspend themselves, 

 M. Duges says that some of them are certainly carnivorous ; but 

 there are some, the green colour of whose intestines indicate a 

 vegetable diet. The larvae, like those of all the others, have been 

 proved to be six footed. He places the genus among the Trom- 

 bidii ; but its spinning qualities seem to show that its proper place 

 is with Tetranychus, with which its other characters do not disagree. 



No. 20. Megamerus celer {Dug., Ann. Sc. Nat., 1834).— 20. Magnified figure of 

 ditto. 



Species incert.s sedis. 



No. 21 



Tetranychus? (Leptus) Americanus 

 Copied from Mr. Riley s fiLfure. 



Tetranychus? AMERICANUS, young (Lep- 

 tus americanus, Riley, Sixth Ann. Rep. 

 Missouri, 52). — 21. Magnified sketch 

 of ditto, copied from Mr. Riley's 

 woodcut. 



Mr. Riley states that this species 

 is found along with Leptus irritans 

 in North America, and that both are 

 there called Jiggers, or harvest mites. 

 They are red like their congeners. 

 Our information regarding both is 

 insufficient to enable us to fix their 

 place. 



No, 22. Tetranychus? irritans, young (Leptus irritans, Riley, loc. cit. supra). — 

 23. Magnified sketch of ditto, copied from Mr. Riley's woodcut. 



This is the Jigger of the Mis- 

 sissippi valleys, where it is ex- 

 ceedingly irritating — whence its 

 name. It acts as one of the 

 representatives in that country 

 of our Tetranychus (Leptus) au- 

 tumnalis; but until the perfect 

 insect is known its place must 



Trombidium (Leptus), irritans. Copied from Mr. Kp^ /^nr»i Aofiircil 

 Riley's figure. ^^ CUlJJCULUld.1. 



