THE APODEMES 



93 



The medifurca is a pair of flat processes which diverge and 

 bridge the commissure, while the postfurca is situated under the 

 commissure. In beetles (Dyticus) Newport states that it is ex- 



Fig. 9S. Meso- (6-Y> and metathoracic 

 ganglia (/Tt), with the apodemes of Gryllo- 

 talpa. After Graber. 



FIG. 99. Parts of the mesothorax of Dyticus : 

 .djinesostermun ; 8., prsescutum ; 8.Z>, scutum; 

 8.c, scutelluni ; 3.rf, iiostscutellum ; S.e, parap- 

 teron ; S.g, mesosternum ; 3,/, episternuin ; 8.A, 

 epimerum ; 3.s, medifurca or entothorax. 



paneled into two broad plates, to which the muscles of the pos- 

 terior legs are attached. Graber also notices in the mole cricket 

 between the apodemes of the meso- and metathorax, a flattened 

 spine (Fig. 98, do) with two 

 perforations through which 

 pass the commissures con- 

 necting the ganglia. Besides 

 these processes there are 

 large, thin, longitudinal par- 

 titions passing down from 

 the tergum (or dorsum), 

 called phragmas; they are 

 most developed in those 

 insects which fly best, i.e. 

 in Coleoptera (Figs. 97-101), 



Diptera, and FIG. 100. Parts of the metathorax of Dyticus : A, 

 metasternum ; 4. a, pitescutum ; 4.fr, scutum ; 4.c, scu- 



a. none being tellurn ; 4.rf, postscutellum ; 4.e, parapteron ; 4./, epi- 

 sterntini ; 4.//, metasternum; 4.A, epimerum; 4.*, 

 developed in the prothorax. postfurca. This and Figs. 97 and 99 from Audouin, 

 /rnl after Newport. 



(I he term phragma has also 



been applied to a partition formed by the inflexed hinder edge 

 of this segment, and is present only in those insects in which 

 the prothorax is movable. Century Dictionary.) All these in- 



