AMERICAN COLKOPTERA. 419 



%. Last ventral segment transversely impressed, nii<l<ile and pustcridi- tibiii' 

 unguiculate at the apex. 



Hab.— Un7Mou, Pa. 



A male specimen which I collected many years ago. In form 

 this species resembles tlie Euroj)eaii C. quadrimaculatu.^ L., but is 

 smaller and without any maculation. The darker line on the middle 

 of the sutural interspace is less distinct than in the preceding species. 



Subtribe Ceutorhynchi. 



A large number of species, all of which, with the exception of 

 one, belong to the genus CentofluincliHa, repi'esent this subtribe, and 

 are at once distinguished from all other members of the present 

 tribe by the pectoral canal not extending beyond the prosternum 

 and the slender, elongate rostrum ; antenn:e very variable, funicle 

 7- or 6-jointcd. Eyes rounded, lateral, widely separated above and 

 more or less covered in repose ; pr(»tliorax narrowed anteriorly, gen- 

 erally constricted at or behind the apex ; scutel distinct in some, 

 scarcely visible in others. Elytra not nnich wider at the base than 

 the })n)thorax, striate and punctured ; [)rosternum long in front of 

 the coxai, deeply and generally narrowly emarginate, with ante-coxal 

 ridges; mesosternum not canaliculate, oblicpie (Ceiitorhynchas), or 

 depressed and transversely sulcate between the middle coxae {Riley- 

 onymns) ; anterior coxie narrowly, middle more widely separated ; 

 middle coxal cavities entirely enclosed {Ceutorhynchas), rarely open 

 within {Rileyonynuis) ; second ventral segment not prolonged on the 

 sides, third widely attaining the lateral margin, segments 3-4 short, 

 fifth longer {Ceidorhyuchus ', segments 8-5 longer, equal (Rileyony- 

 mus) ; femora either dentate or mutic; tibi?e generally slender, mid- 

 dle and posterior unguiculate at the apex in the male (exce[)t atigu- 

 latus group), claws bifid, toothed or simple. 



As indicated above, the establishment of a new genus seems called 

 for. 



Mesostermnn ohliinie. not silicate, middle coxal cavities dosed within, ventral 

 segments 3-5 unecnial, third tarsal joint hilobed- . • -Ceillorliy li<'liii<>«. 



Mesosternnm depressed, transveisely sulcate. middle coxal cavities open within 

 ventral segments 3- ,■) equal, third tarsal Joint not hilohi'd. 



Rileyoiiyiuii!<i. 



€EUTOKIIY\CIIlS. 



With the exception of the characters which distinguish the fol- 

 lowing from the present genus what has l)een .sjiid regtirds the present 

 suluribc in general applies genericnlly here and not nnich else needs 



rKANS. AM. KNT. SOC. XXUI. DKCEMBKK. 1896. 



