86 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 82 



terior, basal region, generally membranous, which Martynov (1925) 

 terms the jugal region. The three wing regions are shown in typical 

 form in the forewing of the grasshopper (fig. 45 A). The preanal 

 region (Pra) is that lying anterior to the anal fold; the anal region 

 is the region of the anal veins (A), the jugal region (/«) is the 

 membranous basal fold of the wing. In many insects the jugal region 

 contains one or two definite veins unconnected basally, or an irregular 

 network of small veins. 



The hind wing of the grasshopper (fig. 45 B), and of other insect? 

 with similar fan-shaped wings, is usually regarded as differing from 

 the forewing in the great expansion of the anal region. According to 

 Martynov (1925), however, the true anal region of the hind wing 

 in Acridium is that part (fig, 45 B, r) between the anal fold, or vena 

 dividens (VD), and the first vein springing directly from the basal 

 support (q) of the anal fan (designated lA in fig. 45 B). Three 

 veins {i, j, k), branching from a common base, lie in this region in 

 the wing of Dissosteira. The following part of the wing, or that 

 containing the veins attached directly to the basal support {q) of the 

 anal fan, Martynov claims is a development of the jugal region of the 

 more primitive type of wing. A jugal area thus developed into a 

 functional wing region he calls the " neala." 



Martynov deduces his interpretations of the morphology of the 

 acridid wing from a general study of the wings in other orders of 

 insects. In Dissosteira, however, the vein designated lA in the hind 

 wing (fig. 45 B) is so clearly the homologue oi lA in the forewing 

 (A), considering the basal relations and the connection with the third 

 axillary sclerite (fig. 47 A, B, sAx), that Martynov's interpretation 

 is not convincing. The area (r) of the hind wing (fig. 45 B), lying 

 between VD and lA, forms the first fold of the anal region (fig. 50 B) 

 in which the vein k occupies the position of a " concave " vein at the 

 bottom of the fold, while the two preceding veins {i, j) strengthen 

 the anterior wall of the fold. The three veins of this region (fig. 

 45 B, i, j, k) are branches of the first primary anal vein (lA). Mar- 

 tynov's general study of the wing regions, however, throws much 

 light on the wing mechanism and morphology. 



Venation of the wings. — While the venation of the grasshopper's 

 wings is comparatively simple, it is difficult to make a satisfactory 

 interpretation of the homologies of the veins in the posterior parts 

 of the preanal regions. If the relation of the vein bases to the axillary 

 sclerites is taken as a guide to the identities of the veins themselves, 

 the veins of the adult may be named consistently in the two wings, but 

 their relation to the nymphal wing tracheae is not clear in all cases. 



