NO. 10 



KEEDINr. ORGANS OF AKACHNIUA — SNODGRASS 



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they are free from each other except at their bases (fig. 8 A, IICx) and 

 the distal ends form a pair of lar^e hairy i)roccsses (cxp). The 

 labrum of the Amblypygi is a very small lobe overhanging the mouth 

 (A, B, Ltn). There is no distinct epistome, but a large, median cpis- 

 tomal apodeme is present (D, tv]/>) between a pair of lateral apodcmes 

 j)roduccd from the bases of the pedipalp coxae (A, B, cAp). The 

 oral aperture beneath the labrum ( B, Mth) opens directly into a 

 simple, tubular pharynx (Pliy), which in cross section is triangular 

 and resembles the pharynx of the Solpugida. Dorsal clilator musclcb 

 of the pharynx arise on the epistonial apodeme, lateral dilators take 

 their origins on the coxal apodemes (A, Phy). Because of the inde- 

 pendence of the pedipalp coxae, and the small size of the labrum. 



cxp 



Chi 



h) IICx Mbh 



Fig. 8. — Pedipalpida-.XmblypNRi. 



A, J itatwdanion joliustoni (Poc.), Phrynidae, showing separation of pedipalp 

 co.xat', \vc!l-devtli)pcd coxal processes (cxf'), relatively small labrum (L»m), ami 

 simple pharynx (Phy) (from Pocock, 1902). B, Phrynichtis bacillifer (Gcrst). 

 Phrynidae, longitudinal section throuj^h anterior end of Ixxly a little to left of 

 median plane (from Borner. 1004). 



the Amblypygi have no distinct preoral food cavity ; the I'ropygi, on 

 the other hand, have a highly specialized prepharyngeal food passage 

 between the large, thick labrum above and the trough of the vmited 

 pedipalp coxae below. 



The Uropygi include the "whip-tailed scorpions" (Thelyphonidae), 

 well known from the East Indian Thclyphouus and the .\mcrican 

 Mastigoproclus. The following description of the mouth parts is 

 based on M. (jigantcus (H. Lucas; of the southern United States. 



The membranous anterior wall of the lx)dy of Masligoproctus is 

 set far back under a long, overhanging part of the carapace, the lower 

 surface of which is strongly sclerotic and bears a median keel. Beneath 

 this projection of the carapace, at the sides of the keel, arise tin* 

 relatively short, two-segmented chelicera, the movable fingers of which 



