32 BULLETIN 63, UNITED STATES NATIONAL MUSEUM. 



and insularis^ probably from iimuaturity, or from aging in the 

 cabinet; in one instance the elytra are described as castaneous (si/b- 

 ci/Ih)driea Casey) ; this unnsnal coloration is undoubtedly due to im- 

 maturity. Dead specimens from long exposure to climatic inclemency 

 become fuscous and even castaneous. In a limited number of species 

 the legs are dark bro^Yn throughout, as in bntruupes Casey. 



Form. — Notably large and elongate as in the males of (//(/(iNtea, 

 oblong as in tricosfata, elongately oblong as in ariita and te.ecma, oval 

 in veterator^ inflated as in veiitricosa and depressed in tibialis. 



/S&se.— Largest in acuta^ texana^ and grandicollis ; smallest in claci- 

 cornis. 



/Surface. — Glabrous and shining, as in deitfipes, gigantea. and 

 omissaj opaque as in tricostata and opaca. 



Sculpturing. — While usually simple it becomes tuberculate in gra- 

 nosa and gran\data\ rugoso-muricate \\\' cordata and nuiricate to a 

 varying degree in many. 



Puhescence. — Body clothed with long flying hairs as in longipilosa.^ 

 pilosa.^ and hirsuta^ or confined to the elytra as in letchcri; hairs 

 short, recumbent and abundant in reterator and opaca. 



Characters that vary within specific limits. — These are the factors 

 Avhich make the limitations of species extremely difficult. Each 

 species may have its extreme large (gigantism) and small (nanism) 

 forms; its smooth and rough forms, elongate and robust forms, v^hile 

 the sculpturing varies from comparatively smooth to rough inde- 

 pendently of size or form. This can be accounted for by environment 

 to a great extent and to certain inherent factors. 



With robustness there is a relative shortening of the appendages 

 and also of their segments, as for instance the joints of the antenn^r 

 from the fourth to the seventh or eighth tend toward equality of 

 length, while in the elongate forms there is a more or less inequality 

 of length evident, the joints decreasing in length more or less from 

 the fourth to the eighth, these joints being comparatively and rela- 

 tively longer as a part of the general habitus. 



These remarks apply most emphatically to the tarsi and their 

 joints as w^ell ; the antennae and legs as a w'hole exhibit this variation 

 of length ; the head varies in size and relative length and breadth 

 even in any particular form. 



So it can be seen why in this particular genus (and this fact is 

 worthy of broader application) that the relative length of parts of 

 any appendage can not always be given as evidence of specific dis- 

 tinctness. These conclusions have been arrived at after a long and 

 tedious recourse to micrometrical treatment of hundreds of specimens. 



In many specimens, especially in the subgenus Eleodes., there is to 

 be observed a more or less evident smooth median pronotal line 



