66 



SMITHSONIAN MISCELLANEOUS COLLECTIONS 



VOL. IIO 



segmented chelicerae (Chi), which are but little invaginated at their 

 bases. The chelicerae are typically arachnoid in form (D), and evi- 

 dently are raptorial in function. Below the chelicerae is an elongate 

 median plate (C, Epst) united laterally with the coxae and terminating 

 in a free lobe that overhangs the mouth. With calls this entire plate 

 "labrum," but he says it consists of a distal and a proximal part. 



Tect 



,-Lin 



Fig. 23. — Acarina-Notostigmata, Opiliacarns segmentatiis With (from 



With, 1904). 



A, capitulum, left side : m, p, coxal lobes associated with the hypostome ; Tec, 

 tectum, or dorsal wall of capitulum. B, telopodite (palp) of pedipalp. C, dorsal 

 surface of anterior part of capitulum below the chelicerae, showing apical lobes 

 of coxae (m, p) and long epistomal plate {Epst) united laterally with the coxae. 



D, left chelicera, mesal. E, longitudinal section of capitulum and anterior end 

 of body. F, transverse section of capitulum through pharynx, anterior to the 

 tectum (E, Tec). 



Since the proximal part is united with the pedipalp coxae and gives 

 insertion to the dorsal muscles of the pharynx (E, F) it is clearly 

 the epistome (C, E, F, Epst) ; the free apical lobe is the labrum (C, 



E, Lm) . 



The smooth, rounded under surface of the capitulum is extended 

 forward beneath the labrum and ends in a pair of suboral lobes (A) 

 that constitute the hypostome (A, E, Hst). At each side of the 



