808 



CLASS V. ARACHNIDA. 



of the Order suggests, are large and conspicuous. The coxae of 

 the pedipalps are produced in towards the mouth. The various 

 spines and hairs on its several segments are of systematic import. 



FIG. 523. Admetus pumilio. Kt Pedipalpi ; Gb flagelliform anterior leg. 



The first pair of ambulatory legs are produced into a long multi- 

 segmented flagellum or whip which is tactile in function. The 

 remaining legs bear a pair of claws and a soft process the " pulvil- 

 lus " is present between the claws in some cases. 



We know comparatively little of the internal anatomy of 

 the Pedipalps. The mouth of Thclyphonus opens into a pharynx 

 which is provided with muscles whose contraction enlarges its 

 lumen ; this passes into a narrow oesophagus which pierces 

 the nerve mass and enlarges into the mid-gut. This gives off 

 two lateral digestive glands which split up into five follicles 

 and two median diverticula which are said to pass through the 

 endosternite. In the abdomen the mid-gut gives off the volumin- 

 ous " liver " which communicates by four paired openings with 

 its lumen. Posteriorly the mid-gut bears a large stercoral pocket 

 which receives at one end or the other the paired malpighian 

 tubules. 



Coxal glands are also well developed and lie under the endo- 

 sternite. Their external opening is still to seek ; if it exists 

 it is probably in the neighbourhood of the third appendage. 



The heart is elongated with two pairs of ostia in the prosoma 



