182 BULLETIN 63, UNITED STATES NATIONAL MUSEUM. 



Habitat. — Texas (Alligator Head, Calhoun County, February, 

 J. D. Mitchell, collector; Corpus Christi, Nueces County, May). A 

 series of nineteen specimens from the Hubbard and Schwarz collec- 

 tions (U. S. National Museum) ; others from the collections of Fall, 

 Fuchs, and Van Dyke. 



Number of specimens studied, 24. 



Type in the- Horn collection. 



Type-locaJity. — '"Texas.'' 



Salient type-chai^acters. — Opaque, subdepressed, sparsely clothed 

 with short yellowish hairs. Form elongate (male) or broadly 

 (female) oval. Base of the pronotum squarely truncate and slightly 

 overlapping the base of the elytra. Pubescence of elytra arranged 

 so as to appear substriate. Sides of the body forming continuous 

 and evenly arcuate lines from head to the elytral apices (Horn). 



Diagnostic characters. — One of the most isolated species of the 

 genus. 



The regularly oval form, equally narrowed anteriorly and poste- 

 riorly, the thorax squarely truncate at base, with the sides regularly 

 arcuate and gradually narrowing from base to the apex, are charac- 

 ters which serve to distinguish it from all other species of Eleodes. 



The anterior tarsi are not dilated in the male. There is a wonder- 

 ful degree of homogeneity of structure among the individuals of the 

 series before me — in fact, one Avould think that they had been cast 

 in the same mold. It bears a superficial resemblance to opaca in its 

 opaque integuments and sparse setiform pubescence, but the above 

 characters will quickly separate it. 



The genital characters place it in a distinct subgenus. I consider 

 it a primitive form that has undergone but little modification in re- 

 cent years. 



Mentum variable, triangular, trapezoidal or evenly rounded at 

 apex, convex at middle and more or less narrowly concave laterally. 

 Prosternum usually horizontal between the coxte and sloping gradu- 

 ally upward anteriorly to the anterior margin; rarely feebly arcuate 

 between the coxa^; feebly dihited behind the equator of the coxje, 

 scarcely produced, vertically truncate behind, with angle rectangular, 

 or feebly produced and sometimes feebly deflexed at the angle. 



Mesosternum vertically and arcuately declivous, more or less feeblv 

 concave. The intercoxal process of the abdomen is subquadrate and 

 feebly transverse; equal in width to the third and fourth ventral 

 segments taken together, the post-coxal part of the first segment is 

 equal in length to the second; the third one-fourth of its length 

 longer than the fourth. 



The abdominal salient is about one-fourth of its width broader 

 than the metacoxal process. The metasternum laterally between the 

 coxae is a little shorter than the width of a mesotibia at apex. 



