Pedipalpi, Ricinulei. and Opiliones. 21 



R. I. Pocock (1911) and especially by A. Petninkevitch (1913). 

 It is remarkable that as to the palaeozoic genus Pnlyochera 

 Scudder, which seems to be rather allied to recent forms, the 

 last-named author mentions only one generic character, viz. 

 that "tarsus of second leg fused with metatarsus, forming one 

 joint", but this character is important, as in the recent forms 

 the second pair of legs has in the adult a separate, well devel- 

 oped metatarsus, and the tarsus live- jointed. 



The material collected by Fea comprises two species, one 

 among them new, while the other species is (ryptostemma 

 crassipalpe Hans. & Sor, which was established on immature 

 specimens, but Fea has secured adult specimens of both sexes. 

 Of the new form a large material is to hand, which enables me 

 to add a little on a couple of points to the description in Hansen 

 & Sorensen's work, and besides to show that a kind of metamor- 

 phosis exists in this order, as I have two specimens of a larval 

 stage with only three pairs of walking legs. 



In the paper mentioned the spiracles and the tracheae in 

 the immature Cryptostemma was described (p. 131 — 132). 

 I have dissected an adult male of C. Fece n. sp. and found a 

 similar structure, so that only one single particular may be men- 

 tioned. On the crescent-shaped spiracles we wrote: "The walls, 

 particularly near the opening, are furnished with short, extre- 

 mely thick, slighth' branching hairs . . . which almost have 

 the character of processes, and at least in part are free of each 

 other". In the adult I have found that both the convex and the 

 concave margin of the crescent-shaped spiracle have a very 

 close layer of processes which are very oblong, and each with 

 a number of moderately short, acute spines in ever}' direction. 

 Each layer has a certain thickness, as it is formed by a few rows 

 of processes. The processes are on both margins shorter towards 

 both ends of the spiracle, and when the processes of the two layers 

 reach each other with their ends, they constitute with their 



