NORTH OF MEXICO. 



301 



either strictly nocturnal in their habits or are found walking in sandy places either in 

 early morning or late in the day, and during cloudy days. The larger and more cylindri- 

 cal of our species will, when disturbed, place their bodies nearly vertically, the head near 

 the ground and the tail erect, and will emit when handled a dark oleaginous offensive 

 fluid, staining the hands brownish and remaining for a long time and apparently fixed by 

 the action of alkaline material. In the warm regions of California the larger species at- 

 tain the age of several years. Their tenacity of life is very great, as specimens have been 

 kept pinned for two months without food or water. 

 Our genera art; three in number. 



Epipleuree broader at base, attaining the humeri. 



Mentum trilobed, lateral lobes more or less indexed. 



Mentum Hat, disooidal. 

 Epipleuree narrow at base, not attaining the humeri. 



Mentum trilobed, lateral lobes indexed. 



ELKODKS. 

 DISCOGENIA. 



KM.UAVJITON. 



BLEODES, Each. 



Elbodbs, Esoh., Zool. Atl. 111., p, 9. 



Xysta, Esoh., (ut supra.) 



Pbomus, Lee., Class. Col. N. A.., p. 888. 



Species have been described by Say as Blaps, by Kirby as Pimclia. 



Mentum somewhat variable in form, usually trilobed, the middle lobe larger and more 

 convex; lateral lobes frequently inflexed, scarcely visible. Last joint of labial palpi trian- 

 gular, narrower than the maxillary, which are broadly triangular or securiform. Head 

 not deeply inserted, suture between epistoma and front frequently distinct, epistoma trun- 

 cate or feebly emarginate, sides sometimes sinuate. Eyes narrow sub-reniform. Antenna? 

 eleven-jointed, the last three or four usually notably depressed, the last joint frequently 

 though not always smaller than the preceding. 



Prothorax variable in form, usually applied against bases of the elytra. Scutellum 

 always distinct and equilateral. Elytra of variable form and sculpture, in many species 

 prolonged behind. Epipleuree always distinct, broader at base and always visible at the 

 humeral angle, gradually narrowing toward the apex. Legs moderately long. Femora 

 newer strongly clavate, the anterior frequently armed in the male, sometimes in both 

 sexes, with a tooth of variable form, rarely all the femora toothed. Tarsi usually chan- 

 nelled and setose beneath ; occasionally the first two joints are dilated and spongy pubes- 

 cent, or not dilated and densely covered witli silken hairs. 



The characters above given arc; those applicable to the whole genus, characters pecu- 

 liar to any group will be given under its heading or in the remarks on the various species. 



The genus Eleodes is our largest and, with the exception of Asida, as previously de- 

 fined, the most polymorphous, and is without doubt the most difficult to sub-divide of any 



AMERI. PIIILOSO. SOC. — VOL. XIV. — 7(> 



