106 MANDIBULATA. — COLEOPTERA. 



suboval : head inserted up to the eyes in the thorax, which latter is subqua- 

 drate and margined : body ovate, stout : legs elongate : tibioe very slender, sub- 

 cylindric, unarmed: tarsi nearly as long as the tibiae, 5-jointed. 



Latreille drew up the characters of this genus by the name above 

 employed in his Histoire Naturelle des Fourmis, published in 

 1802, giving as the type El. Maugetii; and in the same year 

 Illiger, in the first vol. of his Magazin, applied the name Limneus 

 to El. Volkmari, without characters, vide 111. Mag. i. 297. I have 

 therefore followed the former author (not from the mere circum- 

 stance of his having detailed the characters, but from the impos- 

 sibility of determining to whom the priority of distinguishing the 

 genus was due, as their respective works appeared simultaneously), 

 in conformity to the generally received views of modern writers ; 

 though 1 have, perhaps inconsistently, used the term Limniidse to 

 designate the family. 



Elmis differs from Georyssus by its somewhat elongate, convex, 

 body, the five-jointed tarsi, eleven-jointed antennae, and subfiliform 

 palpi : the species all inhabit gently flowing pebbly brooks and 

 rivers, and may be found beneath the stones. 



A. Thorax with elevated lateral lines, 

 a. Thorax without a transverse elevated posterior fold. 



Sp. 1. Volkmari. Oblongus, nigro-subceneus, thorace subquadrato elytris con- 

 vexiore, punctulato, nitido, lineato, lineis antice conniveniibus. (Long. corp. 

 li-lflin.) 



Dy. Volkmari. Panzer.— El. Volkmari. Steph. Catal. p. 53. No. 556. 



Oblong-ovate, black, tinged with brassy, or greenish : head finely punctulate : 

 antennae obscure brown, with the base paler : thorax subquadrate, more convex 

 than the elytra, punctured, shining aeneous-black, with an elevated longitudinal 

 line on each side, remote from the lateral margin, and approaching to each 

 other anteriorly ; when viewed laterally these lines nearly disappear : elytra 

 rather shining, regularly and somewhat deeply punctate-striated, the striae about 

 eight in number, the interstices finely punctulate, and clothed with a scanty 

 down : body beneath and the legs of a dusky or cinereous-black, or pitchy, 

 clothed with a yellowish down : tarsi ferruginous. 



Not common; found in Norfolk, and sometimes near London. 

 " In a mill-stream near Hatfield in June." — Mr. Wesiwood. 



Sp. 2. tuberculatus. Oblongus, fusco aut piceo-ameus, antennis pedibusque rufes- 

 centibus, thorace hilineato, nitido, coleoptris basi obsolete bituberculatis. (Long. 

 corp. \— f lin.) 



Li. tuberculatus. Illiger.— Eh tuberculatus. Steph. CaiaL p. 55, JVo, 557* 



