NO. lo ri:i:niN'(; okcans of ak.m iiniua — .^noim.kass 25 



apparatus for straining out particles of food too large to be swallowed. 



The mouth of the solpugid (fig. y \\. Mth) lies above the edge of 

 a mcinhranous ventral arta in I'mnt of the taprrinj^ anterior end of 

 the narrow (k'uto>tc'rnuni ( US). Diverging at the sides of the mouth 

 from this incmhranous area is a pair of large, flat, soft lol)es (ml) 

 with lon<; apical setae, and each lohe hears a slender, fmely hairy 

 lla.i,H'lluni. These mouth lohes are characteristic features of the sol- 

 pugids. Laterally each lohe lies adjacent to the free margin of the 

 epistomal plate (F). The two mouth lobes, together with the labrum 

 and the sctal brushes, guard the entrance' to the mouth, but they can 

 hardly be said to form a jircoral cavity. The gutterlike deutosternum 

 ( B, 11, 1, I/S) is deeply buried between the mesal surfaces of the 

 pedipalp coxae (I. IICx), and its tapering anterior end ( H) runs out 

 into a shallow median groove that goes forward to the lower margin 

 of the mouth. Possibly this sternal channel also ha> something to do 

 with the oral conduction of food liquids. 



The unusually large size of the epistomo-labral ])late of the solpugids 

 gave the earlier writers on these arachtiids the idea that the solpugid 

 mouth parts constitute a "beak." T.ernard (1895), for example, says, 

 "the beak is a marked feature of the Galeodidae" ; he contended, 

 furthermore, that a beak is a primitive arachnirl structure, best pre- 

 served in the .Solpugida, but variously reduced in the higher orders. 

 Rorncr (1902) refers to the Solpugida and the I'alpigradi as the only 

 arachnids in which the mouth o]>ening is situated t»n a cone, or so- 

 called rostrum. What these writers call a l)eak. Police (1928) terms 

 the "bucco-pharyngcal apparatus." The present writer .sees no reason 

 for regarding the mouth-bearing part of the solpugid as a "beak" or 

 "rostrum" in any true sense. ( )nly the labrum projects as a free lobe 

 (lorsally. witli the mouth beneath its base as in other arachnids, and 

 the ventral mouth lobes are special features of the solpugids. Police 

 ( 1928) contends that the mouth lobes of the .solpugids are homo- 

 logues of the lobes of the jjedipalp coxae in Phalangida and Araneida. 

 which interpretation he says follows from Hcymons' (1905) obser- 

 vation on their develoiMnent. Heymons. however, says merely that the 

 lol)es develop mesad of the coxal processes of the pedipalps ; there is 

 little to suggest that they have any homology with coxal loin's of other 

 arachnids. 



The pharynx ni the .solpugids is an elongate .sack (fig. "(i. Phy) 

 with soft walls devoid of sclerotic plates. In cross section it is tri- 

 angular, but the walls are inflected between the angles, forming a 

 three-pointed star (I. Pity). Posteriorly the lower lo!>c becomes much 

 longer than the upjier lobes (D). Oor.sal dilator nnisclcs of the 



