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- 





Fi<*. 98. Mesii- (fj' 2 i and metathoracic 

 ganglia. ( (?i\ with the apodemes of Gryllo- 

 talpa. After Graber. 



Fir;. 00. Parts of the mesothorax of Dyticus : 

 .^.inesosternuin ; 3., pnescutum ; o.//, scutum; 

 3.C 1 , scutellum ; 3.rf, postscutellum ; H.c, paran- 

 teron ; S.(/, inesosternum ; 3./, epistermmi ; 3.A, 

 epiiiicriun ; 3..v, incrtifurca or entothorax. 



panded 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), 

 Lepidoptera, Diptera, and 

 Hymenoptpra, none being 



sternum ; 4.ij, metasternum ; 4. li, epimenim , 4.0, 

 developed in the prothorax. postfurca. This and Figs. y7 and '.'J from Audouin, 



after Newport. 



(The 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- 



p IO ion. Parts of the metathorax of Dyticus: A, 

 metustfriiuin ; 4.<i, pra-scutum ; 4.//. ^cut^lIll ; i.e. scu- 

 tclliiiu ; 4.r/, ]iost>eutelluiii : 4.<-, |iiini|iti-nui ; 4./, epi 



