LeConte.] APPENDIX. 415 



a. Scales scarcely striate, nearly uniform ; comptus, eximius. 



h. Scales distinctly striate, with longer narrow ones intermixed, which 

 are the bristles of the elytral interspaces. These bristles arc obtuse in quad- 

 rkollis, but acute in the European rumicis. 



B. Scales elongate, striate, truncate and slightly emarginate at tip, 

 opimus. 



C. Scales elongate, striate, acutely and deeply emarginate at tip, with the 

 angles acute prolonged ; setigerm. In the European Pollux the scales are 

 less deeply emarginate. The bristles are similarly striate, but longer and 

 acute. 



D. Scales narrow, cleft, with slender, acute lobes ; bristles longer, acute 

 and simple. 



a. Scales cleft for two-thirds the length, pubicollis. 



b. Scales cleft nearly to the base ; elonjafus, Castor. 



E. Pubescent, without intermixed scales, nigrirostris. 



It is apparent therefore, that valuable characters may be found for the 

 recognition of the species in this difficult genus, by the study of the form 

 of the scales. 



p. 155 add : 



1. Liixus pleuralis Lee, Pr. Ac. Nat. Sc. Phila., 1858, 78. 



This species has a slender form, and is clothed with rather coarse grayish 

 pubescence, with a stripe of paler color at the sides of the prothorax and ely- 

 tra. The beak is cylindrical, rather stout, about twice as long as the head, 

 punctured, carinate for one-half its length, without fovea between the an- 

 tennae ; frontal groove short, deep, antennsE inserted one-fourth from the 

 tip, black ; fuuicle stout, first joint but little longer than the second, which 

 is scarcely longer than the third. Prothorax one-third longer than wide, 

 gradually narrowed from the base forwards, sides straight ; punctures large, 

 shallow, approximate, disc longitudinally broadly and somewhat deeply 

 excavated towards the base ; medial angle produced, obtusely rounded. 

 Scutellum not visible. Elytra a little wider than the prothorax, sides 

 rounded near the base, then converging behind, tips separately slightly 

 prolonged, and acuminate ; striae composed of distant punctures, mostly 

 concealed by the coarse pubescence. Length 7.6 mm.; .30 inch. 



Arizona and Lower California. This species is as slender as L. rubelhis, 

 but the tips of the elytra are only sliglitly prolonged, and the other char- 

 acters are quite different. 



I neglected to mention that the third joint of the tarsi in L. pleuralis and 

 texanus is much less broadly dilated, and the lobes are less obtusely rounded 

 than in the species of division C. The lobes therefore envelop more closely 

 the base of the fourth joint, thus showing a transition from Cleonus to Lix- 

 us, which would probably warrant the separation of these species as a dis- 

 tinct genus. 



The first part of the table might be modified to indicate this difference, 

 which is better than the characters I have used on p. 154. 



