444 Coleopierological Notices, V. 



Eyes normal. 



Proiiotum with a subcentral discal impression ; elytra with a discal stria. 

 Head large, truncate, the antennae very remote ; abdomen with distinct 

 basal carinse ; male with a transversely subrhomboidal and longitudi- 

 nally carinate terminal segment of the venter EuplectllS 



Head generally smaller, the front always more abruptly and strongly 

 narrowed ; antennae less distant ; abdomen without basal carinas ; male 

 with the flat oval subenclosed ventral pygidiura of Ramecia and Actium ; 

 species in general decidedly more minute than in Euplectus. 



Tliesiastes 

 Pronotum without a discal impression ; elytra without a discal stria. 



Bibloplectiis 



lO — Pronotum without a discal impression Triluioplectll» 



11 — Pronotum with the three subbasal fovese, not transversely connected ; 



each usually prolonged forward in an impressed line BibloporilS 



Pronotum having the subbasal foveas connected by a transverse sulcus. 



Antennae moderately distant at base ; eyes rudimentary in the female ; 

 presternum long before the coxae ; tenth antennal joint normal ; pronotum 

 with an elongate discal sulcus ; male with feeble abdominal characters. 



£utyp]ilUH 



Antennae somewhat less distant at base ; eyes nearly similar in the sexes ; 



prosternum short ; tenth antennal joint larger than usual ; pronotum 



with a small subapical discal impression ; body shorter, convex ; male 



with a small flat subcircular and enclosed pygidium at the ventral apex. 



Tliesium 



12 — Prothorax with rather well-defined edges at the sides toward base, and 



with two distinct latero-subbasal foveae on the disk ; elytra with a discal 



stria Actium 



Prothorax without lateral edges or sublateral foveae, the transverse sulcus 

 continued on the flanks ; elytra without discal stria, the latter replaced 

 by a larger deep and subelongate basal impression Triniiopsis 



Distinguishing peculiarities in thoracic structure both pronotal 

 and prosternal, it will be noticed, have been freely used in the above 

 table in defining the genera. I am quite convinced that this is the 

 proper course to take in dealing with the genera, at any rate in 

 some parts of this particular tribe : first, because every distinct 

 peculiarity in the structure of this part of the body, appears to be 

 accompanied by radical divergencies in other important features. 

 Taking the old genus Euplectus as represented within our faunal 

 limits, for example, we find that all of those species without the 

 discal pit of the pronotum are distinguished either (Ramecia) by a 

 formation of the tarsal claws identical with that of Trichonyx, or 

 (Bibloplectus) by an extremely minute size of body and more 



