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XIV. Studies of the Blattidas. By R. Shelford, M.A., 

 F.L.S. 



[Read June 6th, 1906.] 



Plates XIV— XVI. 



I. 



Remarks on the Sub-Families EcTOBiiNiE and Phyllo- 



DROMIIN^. 



A CAREFUL study of the genera composing the sub-families 

 Ectobiinse and Phyllodromiinse has convinced me tliat the 

 characters usually employed to discriminate the members 

 of the respective sub-families are so diverse in structure 

 even within generic limits that but little reliance can be 

 placed on them as criteria of distinction. The short trans- 

 verse supra-anal lamina, the presence of a triangular apical 

 field in the wings or of a large reflected apical area, and 

 the sparse armature of the femora are the so-called 

 diagnostic features of the Ectobiinse. Yet nearly all the 

 species of the genus Anaplecta, and many species of the 

 genus Thc<iaiiopteryx have the supra-anal lamina produced 

 and triangular; again, the triangular apical field appears 

 in numerous species of Phyllodromiinse, sometimes much 

 reduced in size but often as large as in EctoMa lapponica, L. ; 

 now as the presence of this apical field is more or less a 

 mechanical result of a peculiar method of wing-folding, it 

 is a character that may be expected to re-appear in other 

 sub-families oi Blattida}, and such indeed is found to be the 

 case, too much importance therefore should not be attached 

 to it alone as a diagnostic feature. The armature of the 

 femora is also unsatisfactory ; for though the posterior 

 femora of Ectobia and of Anccplecta are armed with only 

 two spines on the anterior margin beneath, in Pseudcctohia 

 and Theganopteryx they are frequently strongly spined, 

 whilst in ChrastoUatta and CaloUatta, two Phyllodromiine 

 genera, the femora are most sparsely armed. It will be 



TRANS. ENT. SOC. LOND. 1906. — PART II. (SEPT.) 



