PROC. ENT. SOC. WASH., VOL. 23, NO. 8, NOVEMBER, 1921 185 



recognized in adults and which he called "Mesofragma (par- 

 tim)"; the protergite, the prescutum ("Prescuto (partim)"); 

 the mesotergite, the scutum ("Metascuto"); and the metater- 

 gite, the scutellum ("Metascutello"). 



The chief objection to this interpretation of Berlese's is that 

 as noted by Snodgrass, in his excellent paper on "The Thorax 

 of Insects and the Articulations of the Wings," 1 Berlese (see 

 Plate IV of the preceding reference) has drawn some purely 

 arbitrary lines across the notum in some figures to support his 

 interpretation, and that this interpretation necessitates the 

 presence of the mesothoracic postscutellum and the metapre- 

 scutum in the same insect. I have not been able to recognize 

 a metaprescutum in the sawfly adults studied and the following 

 quotations from Snodgrass' 'The Thorax of Insects and the 

 Articulation of the Wings" 2 lead to the conclusion that in the 

 Hemiptera and Coleoptera where the mesopseudonotum 

 (mesopostscutellum) is absent a metaprescutum is present and 

 in the Hymenoptera where a mesopseudonotum is present the 

 metaprescutum is absent. 



In the Lepidoptera, however, Snodgrass has recognized a 

 metaprescutum and a mesopseudonotum (see "The Thorax of 

 Insects and the Articulation of the Wings," Plate LX, figs. 150 

 and 151), while Berlese in his figure of Sphinx (Plate IV, fig. 6 

 of the preceding reference) shows an arbitrary division into 



1 



'Proc. U. S. Nat. Mus., 1909, Vol. 36, pp. 511-595. 



2 P. 561, 24th line speaking of Hemiptera: 



"Scutellum of mesonotum forms a large triangle between the bases of fore 

 wings. Mesopseudonotum absent. Metanotum distinctly divided into three 

 transverse parts by transverse lines (87, psc, set, scl). A pseudonotum (87, 

 88, PN) present, very narrow mesially, expanded laterally where fused with 

 epimera (epm.). 



First abdominal tergum (87, 88, IT) a narrow bar fused with metapseudo- 

 notutn, expanded laterally, bearing the spiracles (I sp.) and phragmal arms 

 (I PH)." 



P. 563, 29th line speaking of Coleoptera: 



" Mesopseudonotum lacking unless represented by two small plates (127, 128, 

 131, q) connecting mesonotum and metanotum. 



Metanotum in lower families with Carabidae (132) and Dytiscidae (136) 

 distinctly divided into three transverse parts (psc, set, scl)." 



P. 567, 24th line Hymenoptera: 



"Mesopseudonotum (160, 161, 163, 169, 170, PN 2 ) carries large potsphragma 

 (161, 163, 170, Pph) projecting downward and backward into metathorax. 



Metathorax well developed and of normal shape in Cimbex (164) presenting 

 all the principal pleural and tergal parts (Eps, Kpm, sot, scl, (PN) 3 ." 



3 Note no psc present. 



