24 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I 10 



into a thick, blunt process (E, cxp) projecting mesad of the trochanter 

 (Tr). The coxal processes, however, would appear to have no par- 

 ticular function in connection with feeding. The dorsal surfaces of 

 the coxae (E, IICx) are mostly membranous, but mesally where they 

 join the epistome (Epst) each is strongly sclerotized in continuity 

 with the upper surface of the anterior coxal process. 



The telopodite of each pedipalp (fig. 7 B, Pdp) includes five thick, 

 cylindrical, hairy segments, and an eversible adhesive end organ 

 (Ptar). The end organ is an invaginated sack eversible from between 

 two outer, hairless lips, the structure and mechanism of which has 

 been fully described by Sorensen (1914), by Barrows (1925), and 

 by Kastner (1933b). With each organ are associated the tendons of 

 two muscles, one attached on the inner end of the sack, the other on 

 the lower lip of the outer opening. The everted sack, supposedly 

 forced out by blood pressure, assumes the shape of a stalked, cuplike 

 pad ; the muscles effect its retraction. These end organs of the pedi- 

 palps are evidently the pretarsi, the sacks being probably, as Sorensen 

 says, the homologues of the plantulae, or empodia, of the walking 

 legs. The everted pads are said to be adhesive organs which enable 

 the solpugids to climb on smooth vertical surfaces, and Heymons 

 (1901) asserts that they are used also for catching small insects, 

 which adhere to their exposed surfaces. 



Between the dorsal surfaces of the pedipalp coxae is a large, 

 strongly convex epistomo-labral plate (fig. 7 E, Epst, Lm), the labral 

 part of which projects as a free lobe between the divergent coxal 

 processes {cxp). The labrum of the solpugid is not separated from 

 the unusually long epistome ( E, F ) , and some writers have regarded 

 the whole plate as the labrum. However, since the proximal part of 

 the plate (Epst) is united laterally with the mesal sclerites in the 

 dorsal walls of the pedipalp coxae (E, IICx), and gives origin to the 

 dilator muscles of the pharynx (G, I, did, dll), this part has the 

 distinctive features of an epistomal plate. Along the lines of union 

 with the coxal sclerites (E, F, ccs) are inflected a pair of large, plate- 

 like epistomo-coxal apodemes (E, F, ccAp) that extend proximal to 

 the base of the epistome. 



The relatively small labrum (fig. 7 E, Lm) projects as a free lobe 

 from the end of the epistome, and conceals the mouth below its base 

 (G). On its under surface the labrum bears two large, flat, closely 

 adjacent brushes of long thick hairs beset with many small, delicate 

 barbules, and united by transverse bars (F, G, H), so that each brush 

 forms a fine-meshed sieve. Since these labral brushes guard the 

 mouth behind them (H, Mth), they appear to constitute a filtering 



