. Smithsonian miscellaneous collections. ters are the result of secondary inflections which produce atopographical pattern quite independent of the primary divisions ofthe tergum (fig. 5). Most of the scutal region (fig. 24, Set) and the NO. 2 THORACIC MECHANISM OF A GRASSHOPPER SNODGRASS 43 median triangle of the scutellar region (Scl) are confluent in a largeshield-shaped area that forms the principal part of the tergal depressed posterior lateral parts of the scutum (set, set) are cuttransversely by the faintly-marked sutures (s, s) of the posteriorlyconvergent ridges, which are o
. Smithsonian miscellaneous collections. ters are the result of secondary inflections which produce atopographical pattern quite independent of the primary divisions ofthe tergum (fig. 5). Most of the scutal region (fig. 24, Set) and the NO. 2 THORACIC MECHANISM OF A GRASSHOPPER SNODGRASS 43 median triangle of the scutellar region (Scl) are confluent in a largeshield-shaped area that forms the principal part of the tergal depressed posterior lateral parts of the scutum (set, set) are cuttransversely by the faintly-marked sutures (s, s) of the posteriorlyconvergent ridges, which are obsolete in the metatergum, thoughstrongly developed on the mesotergum (fig. 22 B, s). The posteriormarginal area of the metatergum (fig. 24, Rd), which is a part of thetrue scutellar region, is sharply inflected (fig. 25, Rd^) and is continu-ous with the greatly extended precosta of the first abdominal segment,which constitutes a postnotal plate of the metathorax (figs. 24, 25,PN,). 1Mb ^ Pc Set. ScL Rd Sct^ Scl \ acs ^ —^— •- ^^^. Fig. 25.—Median longitudinal section of mesotergum, metatergum, and meta-thoracic postnotal plate of Dissosteira, showing the phragmatal lobes of theright side. Ac, antecosta; acs, antecostal suture; IT, first abdominal tergum; iMb, 2Mb,secondary intersegmental membranes; iPh, 2Ph, sPh, first, second, and thirdphragmata; PN3, postnotal plate of metathorax, or greatly enlarged precosta offirst abdorninal tergum; Rd, posterior reduplication of tergum; Set, scutum;Scl, scutellum. The lateral margins of the metatergum present the same features asdo those of the mesotergum. The posterior angle of each prescutalarea projects as a small marginal process (fig. 24, n) which is con-nected with the head of the subcostal wing vein by a ligament-likethickening of the basal wing membrane ; it does not articulate with thevein as in the mesothorax. The anterior notal wing process (ANP)is a flat lobe of the scutum, to which the first axillary (lAx) is closely
Size: 2764px × 904px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorsm, bookcentury1800, bookdecade1860, booksubjectscience
