1920] Dti Porte: Muscular System of Grylliis 39 



DORSOVENTRAL MUSCLES. 



Tergo-sternal. 



85. The First Dorsoventral Muscle (Fig. 32). From the 

 anterior end of the lateral edge of the tergite into the para- 

 sternal plate immediately behind the insertion of the tergo- 

 sternal of the first segment. [30]. 



As stated before, the musculature of the parasternal plate 

 indicates that this sclerite is composed of detached portions of 

 the first and second sternites. Muscles 56, LVII, 74, 77, 78 

 and 79 appear to belong to the first sternite, while the others 

 belong to the second. Voss, however, described 85 as an inter- 

 segmental muscle, a mistake no doubt due to the fact that the 

 anterior tergosternals not being developed in any other segment 

 in G. domesticus, he failed to trace the homology. 



86. The Second Dorsoventral (Fig. 32). A straight parallel- 

 fibred muscle originating from the posterior end of the lateral 

 edge of the tergite and inserted into the corresponding region 

 of the sternite. [18]. 



PLEURAL MUSCLES. 



(a) Noto-pleural. 



87. The Fourth Lateral Muscle (Fig. 32). From the 

 postero-lateral angle of the tergite into the posterior pleural 

 sclerite of the second segment. [22]. 



88. The Fifth Lateral Muscle (Fig. 32). Origin as in 87; 

 insertion into the first pleural sclerite of the third segment. [23]. 



(b) Stemo-pleural. 



89. The First Lateral Muscle (Fig. 32). From the para- 

 sternal plate into the pleural membrane in front of the spiracle. 

 Voss regards this as the first and second laterals. The large 

 third pleural sclerite (pss) of the third segment probably results 

 from the fusion and enlargement of the sclerites of the second 

 and third segments, in which case 92 is probably the homologue 

 of the second lateral of the succeeding segments and I have thus 

 regarded it. [19, 20]. 



90. 91. The Dilators of the Spiracles (Fig. 32). Homologues 

 of 78 and 79, and similarly placed. [25, lateral stigmatal a 

 and jS]. 



