2 44 ENTOMOLOG ISK TIDSKRIFT 1917. 



are elongate, useless for walking and evidently serve as or- 

 gans of touch. In the suborder Amblypygi (H. J. Hansen, 

 Û, p. 154) these hairs are found on the distal third of the 

 extremely elongate tarsi, and they are very numerous on the 

 last joints. The hairs, scattered between the normal, pro- 

 tecting setae, are very small, short, conspicuously clavate, 

 and very light; their small insertions differ a little from those 

 of usual hairs. — In the Uropygi we find the tactile hairs 

 in both tribes. In the Tartarides (HANSEN & SöRENSEN c. 

 p. 22) they are found on the six tarsal joints and only a 

 few on each joint; they are easily discernible from common 

 hairs, being very much thicker and somewhat shorter than 

 these; they are, besides, somewhat curved, with the end blunt, 

 while their wall is thin and nearly vitreous. In the Oxopoei 

 the tactile hairs are distributed on the joints of the tarsus, 

 but in Hypoctomis some were besides found on the outer side 

 of the distal part of the metatarsus; in this tribe the hairs 

 are »not only proportionately many times smaller but even 

 absolutely smaller than in Tartarides; besides they are less 

 curved and distally more slender, but their end is yet blunt», 

 and by their vitreous appearance they are easily distinguished 

 from the common setae. 



The Ricinulei (HANSEN & SöRENSEN b, p. 130) do not 

 possess any other external sensory organ than six tactile 

 hairs, each leg of the three posterior pairs having a single 

 hair. It is inserted on the upper side of the tarsus a little 

 before its end, is comparatively rather short, cylindrical with 

 the terminal part thickened, and on the distal two-thirds of 

 the length equipped with delicate branches excepting on the 

 semiglobular apex. The hair is inserted in a small de{)ression, 

 and the area around this depression is peculiarly adorned 

 and markedly different in aspect from the remaining skin of 

 the tarsus. 



The Palpigradi have no eyes, but if Koe7ienia is com- 

 pared with Thelyphonus we find in the former genus on pla- 

 ces nearly answering to the eyes in the latter peculiar sen- 

 sory organs which are transformed hairs. On the front end 

 of the head is seen a small, erect, two-branched organ ; each 

 branch is seemingly lancet-shaped, in reality fusiform, gener- 



