102 LAMELLICOENIA. 



21. Atasnius mariarum. 



Brevius, oblongo-ovatus, valde convexus, postice paullo ampliatus, niger, nitidus, femoribus rufis ; capite lffivi, 

 clypeo profunde triangulariter emarginato, utrinque angulato et breviter dentato, sparsim transverse rugu- 

 loso ; thorace transversim quadrato, angulis posticis rotundatis, lasvi (punctis nonnullis versus angulos 

 anticos exceptis), basi late sulcato-marginata ; elytris profunde catenulato-striatis, interstitiis passim vix 

 convexis, impunctatis, intus perparum crenatis, 4° apice abbreviato ; tibiis 4 posticis apice valde dilatatis 

 et extus robuste spinosis, intermediis dimidio basali extus serratis ; tarsis articulo basali mediocriter 

 elongato ; ventro lsevi, segmentis duobus apicalibus margine anteriore grosse crenato-punctatis. 



Long. 5| millim, 



Eab. Mexico, Tres Marias Islands (Forrer), Manzanillo (Edge). 



By its somewhat shortened hind tarsi this species approaches the genus Psammodius ; 

 the hind tibiae, however, are prolonged into a spine at their outer apex, and the spurs 

 long and tapering as in Atcenius. 



KHYSSEMUS. 



Rhyssemus, Mulsant, Col. de Prance, Lamellicornes, p. 314 (1842) ; Erichson, Ins. Deutschl. p. 909 ; 

 Horn, Trans. Am. Ent. Soc. 1871, p. 290. 



About hve-and-twenty species of this genus have been described. They are spread 

 over the warmer temperate and tropical zones of the Old World, including Australia, 

 Madagascar, and the Malay Archipelago ; but in the New World seem confined to the 

 temperate portions of North America. The following, from Northern Mexico and 

 Guatemala, is, however, an exception. 



1. Rhyssemus cristatellus. 



Subelongatus, fere cylindricus, niger, opacus, elytris cinereo-fuscis, pedibus rufo-piceis ; capite grosse granulato, 

 vertice medio oblique bicarinato, clypeo angulariter emarginato et utrinque angulato ; tborace setis clavatis 

 pallidis marginato, supra rugis quatuor, opacis, granulatis, elevatis transversis, medio subinterruptis, et 

 extus per paria approximatis, partibus depressis subtiliter, margine antico grossius, granulatis ; elytris 

 subtiliter punctato-striatis, interstitiis extus anguste carinatis carinisque uniseriatim eleganter pallido- 

 setosis, carinis (una cum serie setorum) 2, 4 et 6 longe ante apicem abbreviatis ; pedibus posticis calcari- 

 busque gracilibus, tarsis articulo 1° elongato, tenui. 



Long. 2^-3 millim. 



Eab. Mexico, Presidio (Forrer), San Juan Bautista in Tabasco (Edge) ; Guatemala, 

 Paso Antonio (Champion). 



One example only from Paso Antonio, much smaller than the numerous specimens 

 from Presidio. 



PSAMMODIUS. 



Psammodius (Gyll.), Lepeletier de Saint-Eargeau & Serville, Encycl. Meth. x. p. 359 (1825) ; 

 Latreille, Regne Anim. (ed. 4) ii. p. 593; Lacordaire, Gen. Col. iii. p. ]21 ; Mulsant, Col.de 

 France, Lamellicornes, p. 320 ; Horn, Trans. Am. Ent. Soc. 1871, p. 291. 



Psammobius, Heer, Faun. Helvet. i. p. 531 (1841); Gemminger & Harold, Cat. Col. iv. p. 1068. 



