1 4t i am i : k rcAN c< 1 1 . i •:» > i • t e r a . 



extrusioD of the genitalia. In addition to these differences in ven- 

 tral formation, the two genera differ in certain other details of 

 Structure, of which the following are most noteworthy. 



In Melanophthalma. the body is, as a rule, more oval, the elytra 

 often visibly, though usually very slightly, truncate at tip, exposing 

 more or less the tip of the abdomen ; the lateral transverse proster- 

 nal i'ossa is glabrous, and the secondary sexual characters are of a 

 different sort. Further details will be alluded to in the remarks 

 which follow under the generic titles. 



CORTKAKIA Marsh. 

 This genus, as now limited, is quite homogeneous in general 



structure and facies, while involving a moderate amount of variation 

 in details of form and sculpture. The form is more or less elongate, 

 varying from oblong-ovate to subparallel, and from moderately cox - 

 vex to quite strongly depressed. Pubescence more or less long and 

 conspicuous, serially arranged on the elytra. In some species the 

 hairs of the interspaces are distinctly longer and less inclined than 

 those of the striae, but in the majority there is not much difference 

 in this respect, all the hairs being more recumbent. The head is 

 transverse, more or less distinctly though never densely punctati : 

 eyes, a- a rule, large and prominent, rather small in inopia and tem-r 

 poralis; tempora always visible, but very variable in length, never 

 (except in temporalis) evidently longer than one-third the diameter 

 of the eve, as viewed from above. Antennas usually not (juite reach- 

 ing the hind angles of the prothprax, 11-jointed, club 3-jointed ; 

 first joint strongly dilated, subglobular, or a little elongate; second 

 shorter and much narrower, always longer than wide; third sub- 

 equal in length to the second but more slender; fourth to eighth 

 decreasing in length, the seventh nearly always visibly longer than 

 wide, the eighth usually subglobular or slightly tranverse; tenth 

 and eleventh feebly obconic, occasionally distinctly elongate, but 

 usually as wide as, or a little wider than long; eleventh always 

 longer than wide, ovate, more or less obliquely pointed. Prothorax 

 usually subcordate, more or less transverse, front angles obtuse, 

 rounded; hind angles more or le>s obtuse, usually defined by a some- 

 what prominent denticle; surface without carina', and almost invari- 

 ably with a more or less distinct rounded or transverse fovea before 

 the base; sides crenulato-denticulate, more strongly so posteriorly. 

 Elytra elongate ovate or subparallel, each with eight series of punc- 



