NO. 10 



KKEDINT, OKC.ANS OF AKACl I N IDA — SNODGRASS 



49 



those of the first legs opening centrally on the inner surfaces. The 

 nature of the secretion of these glands is not determined. 



The mouth entrance of Phalatujium opilio I., is described by 

 Kastner (1933a, 1935) as a short funnel with its walls thrown out- 

 ward in six radiating folds. The same region is termccl the "buccal 

 atrium" by Police (1927), who shows its structure in two cross 

 sections (fig. 17 A, B). Both writers find that this region is provided 

 with dorsal (anterior) muscles (A. did) arising within the labrum, 

 and ventral (posterior) muscles {dlv) arising on the cpistomo-coxal 

 apodemes. Police notes that the mouth atrium, therefore, can be 

 dilated only in a vertical plane. Kastner says the mouth can be closed 

 by the first circular muscles of the pharynx immediately behind it, 

 and he regards the strong transverse muscle in the base of the labrum 



— Ct 



-Epth 



Fig. 17. — Phalangida-Phalaiigiidae, Phalangimn opilio (I-atr.). 



A, cross section of labrum and moutli region, showing "pscudotraclieal" canals 

 (f) in walls of the latter (from Police, 1927). P., section through same parts 

 farther back, showing transverse muscles of labrum (from Police, 1927). C, 

 cross section through epistonie, cpistomocoxal apodemes (ccAp), and pharynx, 

 ^how•ing groove (g) in dorsal wall of pharynx (from K.istner, 1933a). 



(B, t)ncl) as being also a closer of the mouth funnel, though, as 

 Police points out, it would appear that this last muscle merely com- 

 presses the labrum. The six folds of the mouth, two dorsal, two 

 lateral, and two ventral, are continued into similar folds of the walls 

 of the pharynx (C, Phy). The pscudotraclieal canals of the pedipalp 

 endites (fig. 16 E, c) open into the lumina of the lateral mouth folds 

 (fig. 17A, B, 0. 



The pharynx of Phalangium opilio is s;iid by Kastner to rise 

 vertically from the mouth and then to turn abrubtly backward in a 

 narrowed horizontal part ; in Police's figure of the same species the 

 distinction between the two parts is much less accentuated. The 

 pharynx of Lciobumim (fig. 16 H, Phy) is only slightly curved up- 

 ward ; it runs posteriorly between the large epistomo-coxal apodemes 



