Mannerheim on Eucnemis, Meigen's Dipterous Insects. 431 



characters which are developed by Baron Mannerheim with con- 

 siderable detail. Nevertheless when these are compared with 

 accuracy with those of the Elaiers, it is difficult to conceive in a 

 sufficiently clear manner, in what respects the two genera essen- 

 tially differ from each other. This arises from the author of the 

 Monograph having associated with the Eucnemides, other insects 

 which do not appertain to this genus, which ought to have been 

 confined to his second section, omitting also the species of its 

 third subdivision, the E. Filum and nigriceps. Thus modified, 

 and restricted within its proper limits, the genus Eucnemis will 

 form a group well distinguished from the neighbouring ones by the 

 following characters ; Tarsi with entire joints ; hunches (lamiiKB 

 pedorales posticce^ Mann, meriaia, Knoch) of the two posterior 

 legs closing almost entirely the hinder part of the cavity of the 

 thorax, (metathorax,) fixed, forming triangular plates, capable of 

 completely hiding the thighs; antennce approximated at their 

 base, and lodged on each side in a groove hollowed out immedi- 

 ately under the lateral margins of the thorax ; labrum and ?nandt- 

 bles entirely hidden during repose by the anterior extremity of 

 the sternum, prothorax, epistome or clypeus then applied over it, 

 enlarged and transverse in front. 



In the Eucnemis Filum.) the antennae are always free and un- 

 covered. In other respects it coincides with the characters of the 

 other Eucnemides ; but on account of this difference, it must form 

 a new genus under the name of Cryptostoma. All these groups 

 cannot however be well established without a general revision of 

 that from which they are derived, the genus Elater. 



Systematische Beschreibung der bekannten Europaischen Zwei- 

 Jlugeligen Insekten, Sfc. — Systematic Description of the 

 known Dipterous Insects of Europe, By J. W. Meigen, 

 Secretary of the Chamber of Commerce at Stolberg, Sfc. 

 Vol. iv. 8vo. pp. 428. Plates ix. 



The study of the Dipiera, to which less attention perhaps has 

 been paid than to any other order of Insects, is receiving from 



