. Smithsonian miscellaneous collections. axillary {), which is itself probably a detached pieceof the tergal margin, articulates with the edge of the scutellum. The metatergum.—The tergal plate of the metathorax (fig. 24) issomewhat longer than that of the mesothorax, since it must supportthe wider bases of the hind wings; but in many respects it is moreweakly developed than the mesotergum, there being extensive non-sclerotized areas in the posterior part of the scutal region. The precostal rim of the metatergum (fig. 24, Pc) is narrow, exceptmedially where it forms a conspicuous lip befor
. Smithsonian miscellaneous collections. axillary {), which is itself probably a detached pieceof the tergal margin, articulates with the edge of the scutellum. The metatergum.—The tergal plate of the metathorax (fig. 24) issomewhat longer than that of the mesothorax, since it must supportthe wider bases of the hind wings; but in many respects it is moreweakly developed than the mesotergum, there being extensive non-sclerotized areas in the posterior part of the scutal region. The precostal rim of the metatergum (fig. 24, Pc) is narrow, exceptmedially where it forms a conspicuous lip before the deeply inflected 42 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 82 antecostal suture (acs). The prescutal ridges and their sutures (ps,ps) are much weaker than those of the mesotergum, but they are notconfluent medially with the antecostal ridge and suture, and the lateralprescutal triangles {Psc, Psc) appear to be continuous across the backin a narrow, weakly sclerotized area deflected into the antecostalsuture (acs). 2Ph Pc aPh. R,d AxC Fig. 24.—The metathoracic tergum and postnotal plate of Dissosteira. acs, antecostal suture; ANP, anterior notal wing process; lAx, first axillary,4AX, fourth axillary; AxC, axillary cord; Em, lateral emargination of tergum;n, prescutal lobe to which base of subcostal wing vein is attached; 0, tergal lobeto which posterior end of first axillary articulates; p, tergal arm supportinganal veins of wing (see fig. 47 B) ; Pc, precosta; 2Ph, second phragma: PNs,postnotum; ps, prescutal suture; Psc, prescutum; Rd, posterior fold of tergum(see fig. 25, RdO ; s, s, sutures of secondary tergal ridges; Scl, scutellum; Set,principal part of scutum; set, set, subdivisions of scutum. The surface features of the scutal and scutellar regions of the meta-tergum have even less relation to the generalized structure of a wing-bearing tergum than do those of the mesotergum, because the tergalridges (fig. 23) are here almost completely suppressed, and the
Size: 1612px × 1550px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorsm, bookcentury1800, bookdecade1860, booksubjectscience
