290 ENTOMOLOGICAL NEWS. [July, 'l6 



Blaberus giganteus (Linnaeus). (Plate XV, fig. 1). 



1758. B[latta] gigantea Linnaeus, Syst. Nat., Ed. X, I, p. 424. 

 [America.] 



1813. [Blatta] gigantea Stoll, Natuur. Afbeeld., Kakkerlakken, p. 

 2, Register p. I, pi. Id, figs, i and 2. (No locality given.) 



1865. Bl[abera] stolli Brunner, Nouv. Syst. Blatt., p. 374. [$, Cay- 

 enne, [French Guiana].] 



This species is closely related to B. colosseus (Illiger), 

 differing in the distinctly broader form. The broader pro- 

 notum has, in the female sex, 1 the cephalic portion more 

 ample, the curvature laterad of the cephalic margin less de- 

 cided, thus leaving distinctly more extensive lateral margins 

 which are subparallel for a short distance (as described for 

 gigantea by Illiger). In our material the length of the pro- 

 notum is contained in its width 1.49 to 1.5 times (Saussure 

 gives for this species 1.48 to 1.50). The tegmina are propor- 

 tionately broader, with marginal fields distinctly wider, than in 

 colosseus. Linnaeus gives "diametro ovi gallinacei" for this 

 species ; the series before us of colosseus are decidedly too 

 slender to fit this description. 



We have given Stoll's reference, as Brunner has described 

 such material as B. stolli. We are satisfied that the features 

 given by Brunner for the separation of that condition are of 

 no specific diagnostic value, being due to recessive coloration 

 and slight individual differences in the interocular width and 

 rounding of the apices of the tegmina. 



The great size and very pale buffy general coloration of 

 giganteus and colosseus readily distinguish them from any 

 other species of the genus. Both agree in numerous features 

 of interest given here under the latter species. 



Measurements (in millimeters). 



Length Length Width Length Width Width Length in 

 of of pro- of pro- of of of costal width of 



9 body 2 notum notum legmen legmen field pronolum 



Cincinnati, Colombia 66.0 17.3 25 8 66.8 25.2 8.3 X 1.49 + 



Cincinnati, Colombia 58.2 17.2 25.7 66.2 25.8 8.4 X 1.5 + 



Cincinnali, Colombia 630 16.6 25.0 65.3 25.0 8.0 X 1.5 



1 Lack of males of the present species is unfortunate, but it is prob- 

 able that the contrast between the sexes in giganteus is in every way 

 comparable with that found between the sexes in colosseus. 



"The body measurement is taken to the apex of the subgenital plate; 

 the supra-anal plate, in the present genus, extends beyond this point. 



