AT^NIUS. 99 



The largest species of the genus, 7-8 millim. long. The thorax is not margined at 

 the base, except near the lateral angles. 



13. Ataenius imbricatus. 



Aphodius imbricatus, Melsh. Proc. Ac. Phil. 1844, p. 136 \ 

 Atanius imbricatus, Horn, Trans. Am. Ent. Soc. 1871, p. 285 2 . 

 Ataenius sordidus, Harold, Col. Hefte, v. p. 103 3 . 



Hdb. Noeth America, Pennsylvania 1 . — Mexico 23 , Guanajuato {Salle), Jalapa, 

 Mazatlan {Edge) ; Honduras 2 {Salle). — South America, Amazons 2 , Brazil 2 ; Antilles, 

 Cuba 2 . 



14. Ataenius gracilis. 



Oocyomus gracilis, Melsh. Proc. Ac. Phil. 1844, p. 137 \ 



Atcenius gracilis, Harold, Berl. ent. Zeitschr. 1867, p. 281 2 ; Chevr. Ann. Soc. Ent. Er. 1864, p. 414 3 ; 

 Horn, Tr. Am. Ent. Soc. 1871, p. 286 \ 



Hah. North America 1 2 4 . — Mexico, Northern Sonora {Morrison), Presidio {Forrer), 

 Cordova {Salle), Vera Cruz {Salle, Hoge), San Juan Bautista in Tabasco (Hoge) ; 

 Guatemala, near the city, Capetillo, Cubilguitz, Paso Antonio (Champion) ; Nicaragua, 

 Chontales (Janson). — South America 2 ; West Indies 2 3 . 



In its narrow sublinear form this insect approaches the species of Section II. The 

 outline of the clypeus is different from that of A. strigatus and its allies, for although the 

 sides of the emargination are not pointed, they are slightly angulated and not broadly 

 rounded. A. gracilis may be distinguished from other small and narrow species by 

 the more or less distinct dorsal furrow of the thorax. 



II. Clypeus acuminated or dentate on each side of the emargination. 



15. Ataenius figurator. 



Atmnius figurator, Harold, Col. Hefte, xii. p. 24 \ 



Hdb. North America, Louisiana 1 . — Mexico, Presidio (Forrer), Cordova (Salle), 

 Frontera in Tabasco, Zacualtipan, Durango city (Hoge). 



A sublinear species with polished, impunctate, and flat elytral interstices. Harold did 

 not include it in the group with bidentate clypeus ; but the numerous examples which 

 I have examined, and which otherwise agree with his description, show the points on 

 each side of the emargination very conspicuously. 



16. Ataenius polyglyptus. 



Oblongus, mediocriter convexus, niger, obscurus, parum rdtidus ; capite postice crebre punctulato, medio con- 



00 2 



