PROC. ENT. SOC. WASH., VOL. 23, NO. 8, NOVEMBER, 1921 183 



Anterior mesothoracic phragma 



Mesoprescutum 

 Mesoscutum 



Mesoscutellum 



Membrane between scutellum 2 and 



ppstscutellum 2 

 Mesopostscutellum 

 Posterior mesothoracic phragma 

 Metascutum 



Metascutellum 



Membrane between scutellum 3 and 



postscutellum 3 

 Metapostscutellum 



margin D A (mesothoracic 



side). 



A mesothorax 

 B and latero dorsal and su- 



praalar discs C. 

 subdorsal discs C. 



D mesothorax. 



A metathorax. 



margin A B (metathorax). 



B and laterodorsal and 



supraalar discs C. 

 Subdorsal discs lobes C. 



D metathorax. 



A first abdominal tergite. 



Lai 



rva 



Rdi/lt 



T-I 



RB C D 



-* ' 



o 



I 



o 



CL 



MTU: U I 

 BCD^R BCDiR 



T 



e V I g ^ 



r ^ k "=: ^ 



>- -J "O 



i o -^ w -Q 



^"3 "3 I 



CL (/) UO ^ 



g ! 



E -HI 



. 

 



0- ' 



^ a 

 X) <O 



4 ' |V cJ ' v l 4. 4 



rotljorax ;ll lesotnorax (Ictatnorax 



0. 

 Oi 



Conclusion. 



The foregoing observations on the structure of the larvae of 

 sawflies supports the findings of Doctors A. D. Hopkins and A. 

 Boving on Coleoptera. Dr. Hopkins, in his fine monograph on 

 'The Genus Dendroctonus," 1 recognized four transverse seg- 

 mental divisions in adult, larva and pupa. Of these four trans- 

 verse segmental divisions Dr. Hopkins finds clearly represented 

 in the tergites of the larval thorax, two, the prescutal and scutel- 

 lar divisions with evidence of a third, the scutal division, on the 

 sides and in the abdominal tergites 1-6, three, the prescutal, 

 scutal and scutellar divisions. 



"The Genus Dendroctonus." U. S. Department of Agriculture, Bureau of 

 Entomology. Technical Series, No. 17, Part I, \W), pp. 24-26. 



