10 GEO. II. HORN, M. D. 



Group B. 



Sciite]lura small. Front distinctly trituberculate, clypeus in sev- 

 eral species witli a ti^ansverse ridge. Anterior tibice distinctly tri- 

 dentate, feebly crenulate above, the first joint of the tarsus shorter 

 than the second. Hind tibi?e fimbriate with short equal spinules, 

 the first joint of the tarsus variable in length. Mesosternum not 

 carinate. 



The species of this group although not numerous are of difficult 

 study. The group is not very homogeneous, and the species are ag- 

 gregated from the possession of certain striking charactei's above 

 noted. 



The following table will assist in distinguishing the species : 



Clypeus emargipate, the angles on each side acute, almost dentiform. 



Small species, totally black, first joint of hind tarsus not as long as next three. 



crassulus. 

 Large species, elytra clear red, first joint of hind tarsus as long as next three. 



bi<leiii§. 

 Clypeus feebly emarginate, the angles on each side rounded or at most obtusely 

 prominent. 

 Thorax dissimilar in the sexes, compressed in front in the male: elytra clear 



red fiiiietai'iiis. 



Thorax similar in the sexes, elytra piceous or dull red. 



Anterior angles of thorax paler, usually with a conspicuous yellow spot, 

 sometimes barely perceptibly paler. 

 Clypeus without trace of transverse carina. 



Clypeus on each side of emargination rounded in both sexes ; strise of 



elytra not deeply impressed, intervals very fiat....coiigi'egatus. 



Clypeus on each side subangulate, more so in 9 ! stripe of elytra deep, 



crenately punctate, intervals convex aloiitus. 



Clypeus subangulate; striae of elytra fine, intervals flat; elytra uni- 

 formly reddish brown fceti<ltis. 



Clypeus with distinct transverse carina. 



Elytra deeply striate, ci-enately punctate, intervals con vex.... duplex. 

 Species totally black, anterior angles of thorax never paler. 



Clypeus with ti-ansverse carina; elytra finely alutaceous, sul)opaque. 



pectoralis. 

 Clypeus without trausverse ridge. 



Small species (.18-.22 inch) fiicies robust I'lirieola. 



Large species (.28-. .30 inch) oblong. aiithraciiiii!^. 



A. crassulus Horn. — Form short, roltust, broader behind, likick, shining, 

 legs rufo-piceous. Antennie, reddish brown. Head coarsely punctured, sparsely 

 on the vei-tex, more densely in front. Clypeus emarginate at middle and on each 

 sharply angulate or dentate, the sides arcuate, gense slightly prominent, but ob- 

 tuse. Thorax slightly narrower in front, sides feebly arcuate, hind angles very 

 obtuse, disc convex, the punctures rather coarse, very regularly distributed, not 

 closely placed Elytra .slightly wider behind the middle, humeri obtu.se, disc 



