LeConte.] 



BAKIXl. 301 



MADARUS Sch. 



In this genus the upper surface is very smooth and shining, and the sur- 

 face of the elytra undulated, but the beak is longer than the prothorax and 

 slender, almost as in Centrinus; the antennae are longer and more slender, 

 the first joint of the funicle as long as the three following; club elongate 

 oval, annulated, entirely pubescent. Tlie presternum is extremely wide 

 and gibbous between the coxoe; declivous in fnmt, not excavated, but with 

 two verj' short impressions. Front thighs armed with an obtuse tooth, 

 claws approximate, but not connate at base. 



The preceding genus makes a gradual transition from Baris to Madarus, 

 and the arrangement of Lacordaire by which the genera just named are 

 separated in two different subtribes is manifestly unnatural. 



1. M. undulatus Boh., Sch. Cure, iii, 640; RhyncTimius und. Say, 

 Journ. Ac. Nat. Sc. Phil, iii, 315; ed. Lee. 11, 177. 



Massachusetts to Alabama, Texas, and Kansas. The northern specimens 

 are entirely black; those from the South and West have the prothorax red. 

 Although Boheman described all the thighs as toothed, I find that tlie mid- 

 dle and hind pairs are quite unarmed. The tooth of the front pair is rather 

 large, but obtuse. 



Group II. Centriiii. 



The only characters I can give for the recognition of this group, as dis- 

 tinguished from Barides, are : the elytra conjointly rounded at tip, or 

 nearly so ; the pygidium thus becomes entirely covered, or onlv partly 

 exposed, and is nearly horizontal, or at most somewhat oblique, and never 

 vertical. Tlie last ventral is consequently regularly rounded at tip, never 

 truncate or emarginate. In addition to these characters the ventral surface 

 of the abdomen is more convex, frequently ascends obliquely, as in Zygo- 

 pini, but in a much less degree. The tibial hooks are less developed than 

 in Baris and its allies, and in many species are scarcely apparent. The 

 beak and antennae are generally of more slender form than in Baris, but 

 these characters are not without exceptions, as will be seen below. 



A. Body without erect bristles. 



Tibiae stout, with longitudinal grooves (as in Baris) 2. 



" slender, not grooved 3. 



2. Pectoral groove shallow, indefinite PACHYB ARTS. 



deep, sharply defined STETHOBARIS. 



3. Side margin of prothorax as usual 4. 



well defined MICROCHOLUS. 



4. Tliird joint of tarsi broad, bilobed 5. 



narrow CALANDRINUS. 



5. Claws separate CENTRINUS. 



" connate at base ZYGOBARIS. 



" single BARILEPTON. 



B. Body with stout erect bristles, intermixed with 



the dense covering of scales; tarsi narrow. 



Bristles very long EUCH^ETES. 



" short PLOCAMUS. 



