L 



REVISION OF ELEODIINI BLATSDELL. 42 Y 



Hacienda de Bleados; Parras; San Pedro in Coahuila, Doctor 

 Palmer). 



Number of specimens studied, 86, 



Type is in the LeConte collection. 



Type-locality. — " Flumen Gila" (LeConte). 



Salient type-characters. — Elongate, black. Thorax obsoletely punc- 

 tulate. Elytra finely punctulate, punctures subseriate (LeConte). 



Diagnostic characters. — Closely related to gigantca^ from which 

 it differs by the frequent elongate fusiform or subcylindrical shape. 

 The females frequently have the elytra more or less flattened on the 

 dorsum. 



The prothorax is less arcuate at the sides, chiefly because the disc 

 is quite strongly and transversely convex, with sides more or less 

 strongly and arcuately deflexed and in many instances more or less 

 feebly inflexed as well, so that the margin is completely invisible 

 when the prothorax is viewed vertically from above. 



The pronotum is only apparently longer than wide, for by direct 

 measurements and in tracings I do not find much difference between 

 longicollis and gigantea. 



There is usually only a very slight antero-posterior convexity and 

 this is a good differential character in separating the species from 

 gigantea, but it can not be relied upon entirely. 



Some specimens from the Colorado Desert Region and Orange 

 Count}', California, are as nearly intermediate between longicollis 

 and gigantea as any forms can be, and these mesotypes approach 

 cstriata as well. 



I consider the two species as modifications of a single and rather 

 recent ancestral form, one rannis of this dichotomous divergence 

 extending westward and northward, the other eastward and north- 

 ward. 



The sculpturing of longicollis is the same as in gigantea — surface 

 smooth, polished, finely and sparsel}^ punctate, but more coarsely 

 sculptured specimens are frequently found, and some are even sub- 

 striate. 



The specimens described by LeConte as haydenii is a variation 

 along this line; the differential characters given are as follows: 

 " Thorax is more rounded on the sides, more distinctly punctulate, 

 tJie 7'ows of punctures of the elytra are much more evident, and the 

 curvature from the back to the sides is abrupt, while in longicollis 

 it is regular and uniform ; the elytra are also more elongate near the 

 apex, so as to produce at the inflexed margin a very slight concavity." 

 It is only a sjaionym. 



Specimens collected by Doctor Palmer in Mexico had the elytra 

 distinctly but finely punctato-striate ; other forms w^ere taken but all 

 referable to the present species. 



