32 



SMITHSONIAN MISCELLANEOUS COLLECTIONS 



VOL. IIO 



coxal trough is the rounded labrum (C, Lm), which is supported on a 

 large epistomal plate (Epst) united laterally with the dorsal walls of 

 the adjoining parts of the pedipalp coxae. The epistome and the 

 labrum together are regarded by Hansen and Sorensen as "pars 

 basalis" and "pars apicalis" of the labrum, but these writers note the 



Cue Chi 



Cue Pdp 



Epst 



A, Ricinoides crassipalpe (H. & S.), ventral, with cucullus {Cue) turned 

 forward exposing the chelicerae (outHne from Hansen and Sorensen, 1904). 

 B, R. westermanni (Guerin), cucullus closed over labrum and chelicerae (from 

 Karsch, 1893). C, R. crassipalpe (H. & S.). rnouth region, dorsal, showing 

 pedipalp coxae completely united in a broad under lip (Hst) ; x-x, line of in- 

 vagination of basal parts of coxae and epistome (from Hansen and Sorensen, 

 1904). D, R. karschii (H. & S.), chelicera (from Hansen and Sorensen, 1904). 

 E, R. sjostedtii (H. & S.), segmentation of the pedipalp (outline from Hansen 

 and Sorensen, 1904). 



distinctive features of the two parts, and that the "pars basalis" gives 

 attachment to the dilator muscles of the sucking pump. The basal 

 parts of the coxae and the greater part of the epistome are said to 

 be invaginated into the body cavity proximal to the line x-x of the 

 figure. 



The internal part of the ingestion apparatus of the Ricinulei is not 



