314 LAMELLICOENTA. 



Subfam. PENTODONTIN^E. 

 EUETHEOLA. 



Gen. Stenoerati et Beteronycho affinis, sed differt tarsis anticis tf simplicibus. Corpus cylindricum. Clypeus 

 antice valde angustatus, apice bidentato-reflexus, carina frontali medio late interrupta. Mandibular extus 

 valde sinuatas, apice sursum reflexas, margineque apicali lato, obtuso (interdum extus subdentatas, apice 

 extus et supra reflexae) ; maxillae apice crasse quinquedentatse ; mentum convexum ; palpi fusiformes. 

 Thorax simplex. Tarsi antici utroque sexu simplices ; postici articulo primo triangulari. Prosterni 

 processu postcoxali apice antice rectangulariter reflexo ibique planato. Organa stridulantia desunt. 



This new genus is necessary for the reception of the Heteronychus humilis of 

 Burmeister, a species which its describer afterwards excluded from Heteronychus on 

 account of the absence of stridulating-surface from the propygidium, and which also 

 differs from Heteronychus by the simple claw-joints of the male anterior tarsi. The 

 under surface of the elytra near the margins is clothed with fine laid hairs. In the 

 bidentate clypeus Euetheola much resembles JDyscinetus bidentatus, from which it gene- 

 rically differs again in the simple fore tarsi of the male, and also in the shape of the 

 mandibles. The last-mentioned character separates it from Stenocrates, with which 

 genus it has the closest affinity, and to one species of which (S. holomelcena) it bears 

 so striking a resemblance that if the mandibles formed the only point of difference 

 a generic separation would scarcely be justified; but Euetheola has a further distin- 

 guishing character in the short basal joint of the hind tarsi, which effectively separates 

 it from Stenocrates, the latter having this joint always long and linear. 



l. Euetheola humilis. (Tab. XVIII. fig. 14.) 



Heteronychus humilis, Burm. Handb. der Ent. v. pp. 93 1 , 539. 



Hah. Mexico, Tuxtla (Salle), Tlacotalpam, Cordova (Hoge) ; Panama, Lion Hill 

 (McLeannan). — South Ameeica to South Brazil 1 . 



A Panama specimen is figured. 



LIGYEUS. 



Ligyrus, Burmeister, Handb. der Ent. v. p. 542 (1847) ; Lacordaire, Gen. Col. hi. p. 408. 

 Tomarus, Erichson, Wiegm. Archiv fur Naturg. 1847., i. p. 95. 



About a dozen distinct species of this genus have been described, all American, and 

 spread over the temperate as well as the tropical zones. The characters given by 

 Burmeister and Lacordaire require to be modified as regards the fore tarsi, which both 

 authors give as simple in both sexes, but which in about half the species have the 

 outer claw, in the male, thickened and deflected. The species are otherwise so closely 

 related, all agreeing in the singular position of the stridulating-surface, viz. underneath 

 the apical part of the elytra, and not, as in the Dynastidee generally, on the propy- 

 gidium, that the genus cannot well be divided. The mandibles are broad and 

 flattened, with their apical edge armed with two teeth, and their outer edge strongly 

 rounded, or in some cases forming a third tooth. 



