MORGAN HEBARD 155 



Planudes cortex new species (Plate XXII, figs. 2, 3 and 4.) 



This insect shows remarkable dissimilarity in the sexes; the 

 male slender and having fully developed organs of flight, the 

 female moderately stout and showing only the merest vestiges of 

 tegmina. The dissimilarity in form is slightly more pronounced 

 than in Creoxylus spinosus (Fabricius),^" in which species, also a 

 member of the Prexaspes Division, similar sexual differences in 

 the organs of flight are found, these in neither case being of any 

 generic diagnostic value. 



In a species such as the present, showing no lobation of the 

 limbs or conspicuous projections of the body, it is very difficult 

 to associate the sexes. In body proportions, the female, though 

 decidedly heavier, agrees with the male in proportionate length 

 of head, pronotum and mesonotum, and these portions, though 

 much more heavily nodulose, show a general similarity of contour 

 and structure. The limbs in the female are all stouter, the cepha- 

 lic femora distinctly more lamellate and the tarsal joints shorter 

 than in the male, but the relative proportions of the cephalic and 

 caudal limbs are the same in both sexes; these features show 

 similar differences in the sexes of Creoxylus spinosus but to a 

 slightly lesser degree. The sculpture of the head in the ocellar 

 area and facial scutellum, the black basal joints of the palpi, the 

 hirsute antennae, the length of which differ in approximately 

 the same ratio as found in the sexes of related species, and the 

 similarly developed carinae of the limbs (except the greater 

 lamellation of the cephalic femora in the female), all of which 

 are similarly strongly hirsute, give us reason to believe this asso- 

 ciation to be correct. 



The female shows the close relationship of the species to P. 

 molorchns (West wood), apparently differing in having vestigial 

 tegmina, the fifth dorsal abdominal segment simple and the form 

 slightly heavier, the mesonotum and metanotum distinctly 

 shorter. 



The male, in Redtenbacher's key, would run to his Isagoras 

 plagiatus, from which species this specimen is readily distinguished 

 by the dissimilarity of proportions, this most striking in the 

 caudal femora being distinctly longer than the cephalic. 



'<• A large series of this species from Trinidad is in the Hebard Collection. 



TRAXS. AM. Ei\T. SOC, XLV. 



