JAMES A. G. REHN 245 



the type, while the tegmina are cinnamon-huff instead of clay 

 color. We consider the type to represent a recessive type of 

 coloration, while the Caparo female is the intensive extreme, the 

 Porto Velho specimen holding an intermediate position. 



The measurements (in millimeters) of the three specimens 

 before us are as follows: 



>« 3 



O -^ 4iC 'o'^ ^o B 



■s.>^ Sa 



■£ a 



!D 



Mo M ii rt ~ mm 'S 



£-^ £ - t^ ^^ g'o 



kJ fJ O J o 



cf Porto Velho, Brazil 36 10.5 15.7 41 14.5 



9 Caparo, Trinidad 46.3 13.4 19 50 19.2 



9 Santa Clara Plains, Costa 



Rica, type 42 11.5 16.0 42 15.7 



The size variation is, of course, either geographic or individual 

 and in the present genus is quite a frequent occurrence. The 

 male sex has never been previously examined. The only features 

 in that sex which show noteworth}- differences from the female 

 are that the least interspace between the eyes is distinctly less 

 than the greatest dorso-ventral depth of the eye, while the sub- 

 genital plate is of the size and form usual in this genus and 

 moderatel}^ unsymmetrical, the dextral style situated at the 

 bottom of an arcuate emargination. The face of the male is 

 solidly blackish fuscous, which is true of the Caparo female as 

 well, the ventral surface of the abdomen is solidly of the same 

 color except for a narrow buffy lateral margin, extending from 

 the base of the abdomen to the apex, represented on the subgeni- 

 tal plate by a complete but very delicate edging. 



The section of the genus Blaberus containing B. posticus, 

 biolleyi and jonoratus, with other species which may be distinct 

 from these three, or synonymous with the first and third, con- 

 stitute a valid group, quite removed from the bulk of the Blaberus 

 forms. The acquisition of more material and a study of the 

 constancy of certain features may result in making necessary the 

 erection of a genus for their reception. 



CORYDIINAE 

 Euthyrrhapha pacifica (Coquebert) 



1804. BlaUa pacijica Coquebert, Illustr. Iconogr. Insect., iii, p. 91, pi. xxi, fig. 

 1. [Islands of the Pacific Ocean.] 



Manaos, Amazonas. (Mann and Baker.) One male. 



TRANS. AM. ENT. SOC, XLII. 



