22 Studies on Arthropoda. I. 



lateral thorns a kind af sieve for the air. The processes are 

 light brownish. 



In 1904 we showed that in the female of the large form Cryp- 

 tostemma Afzelu Thor. the sternites of first and second abdo- 

 minal segments are freely movable, crescent-shaped, with their 

 concave margins turning against each other, and they surround 

 together the genital aperture; both sternites are only visible, 

 when the abdomen is bent much upwards. In C. Fece n. sp. 

 I find the same structure, but the sternites are a little less robust. 

 In this species and probably in all other forms of the order 

 the genital aperture is in the male much smaller than in the 

 female; the sternite of second segment is very thin and semi- 

 circular or in reality curved so much, that it occupies about 

 three-fifths of a circle; the sternite of first segment is produced 

 downwards as a freely protruding, triangular plate about as 

 long as broad and with the end subacute. The same plate is 

 also found in the adult male of C. crassipalpe. An internal co- 

 pulatory organ is, as might be expected, completely wanting, 

 but according to my dissection of a single male, the inner sexual 

 organs and the alimentary canal can scarcely be made out 

 with certainty without fresh material or at least the sacrifice 

 of several well preserved specimens of both sexes. 



The Larva. -- The body is about 2.3 mm. long, second 

 leg 3.3 mm. In general aspect the body of the larva is in the 

 main similar to half-grown specimens, differing in being compa- 

 ratively a little broader, with the grooves on cephalothorax 

 partly feebly developed, partly wanting, and without grooves 

 on the cucullus, while the tergites of the abdomen and the gra- 

 nulation are nearly as in postlarval younger stages. But. the 

 larva has only three pairs of walking legs, as the 

 fourth pair is completely wanting (pi. Ill, fig. I g). 

 That it is the fourth pair which is wanting is seen from 

 the fact, that the coxae of first, second, and third pairs 



