NO. lO 



I'KKUINC (il«,AN.> Dl' ARA( IINIDA — SNODCRASS 



59 



of the pedipalp sternum is a short preoral cavity (fig. 20 C ; fig. 21 P., 

 FrC) closed laterally by the lobes of the pedipalp coxae. The mouth 

 at the inner end of the jircoral cavity ojicns directly into the jtharvnx. 

 The pharynx rises steeply from the mouth hihind the labrum and 

 epistome (fig. 21 .'\. Phy). in a cro.ss .section of the pharynx of 



E G 



Endst 



Fig. 21. — Arancida-Dipncumonomorpliae. 



.-\, Agclcua uacvia Walck., diagrammatic longitudinal section of the prosoma. 

 showing muscles of the stomodacum (from Brown, 1939). B. Dysdera crocala 

 C. Koch, lahrum, pedipalp sternum, and pharynx, left side. C, Heterof>oda 

 venatoria L., labrum and dorsal plate of pharynx, ventral. D, same, oesophagus 

 and proventricular pump, muscles removed. I£, same, cross sections of pharynx, 

 oesophagus, and proventricular pump. F, Tcgcttoria dotiu-stica (CI.), longi- 

 tudinal section of piece of dorsal plate of pharynx, showing transverse ridges, 

 greatly magnified (from Bartels, 1930). G, /igelctuj nact'ia Walck., cross 

 section of proventricular pump, with muscles (from Brown, 1939). 



Heteropoda venatoria (E, Phy), the organ is seen to be much flattened 

 dorsoventrally. In its dorsal (anterior) wall is a well-developed 

 plate (C) traversed by a median channel (dc) ; the opposite wall is 

 weak except for a scleroti/.ed band along each lateral margin, which 

 is connected liy nirmbranc with the dorsal plate. The channel of the 



