NATURAL SCIENCES OF PHILADELPHIA. 311 



dorsal line reaching from the base to the middle, marginal stria deeper on 

 the fore part. Elytra parallel, with two striae at the base near the shoulder, 

 the internal one very small, the external one more apparent but short, lateral 

 fossa profound, attenuated behind. Propygidium anteriorly at the sides very 

 sparsely and coarsely punctate, pygidium tolerably densely punctate. Epipleurae 

 rugosulous, unistriate. Body beneath impunctate, the pleurae very thickly and 

 coarsely punctate. Prosternum rounded at the apex, with an anterior oblique 

 margin on each side. Antic and intermediate tibiae four-toothed, the posterior 

 three-toothed. Length *67 : including the jaws - 8. 



By far the largest of the known species of this family. The Oxysternus, 

 hitherto considered the largest Histeroid, is -5 in length. 



Omalodes r o t u n da t u s . Rotundus, convexus, niger nitidus, fronte stria 

 circulari integra medio paulo emarginata ; pronoto lateribus impunctatis ; 

 elytris stria dorsali prima integra, secunda postice abbreviata, tertia medio in- 

 terrupta, quarta utrinque abbreviata, suturali basali, parva, brevi. 



Mexico. 



Round, convex, black, very shining ; front impressed with a circular entire 

 stria, a little emarginated in the middle. Thorax stria entire, ambient, the 

 sides impunctate. Elytra with the shoulders projecting, humeral stria scarcely 

 apparent, subhumeral abbreviated in the middle, first dorsal subentire, second 

 abbreviated behind, third interrupted in the middle, fourth abbreviated on both 

 sides and placed opposite the interruption of the third, sutural small, short, 

 basal. Epipleurae, sternum and mesosternum impunctate, the first unistriate. 

 Propygidium thinly, pygidium densely punctate. Antic tibiae four-toothed. 

 Length -35. 



Phelister af finis . Ovalis, convexus, niger, nitidus fronte concava; pro- 

 noto puncticulato, stria marginali integra; elytris laevissimis, striis punctatis, 

 dorsalibus quatuor primis integris, quinta et suturali aequalibus, antice ante 

 medium abbreviatis, subhumerali ante medium antice valde abbreviata ; py- 

 gidio punctato. 



Mexico. 



Oval, convex, black, shining, frontal stria rounded. Thorax entirely punc- 

 ticulate, the marginal stria entire. Elytra very smooth, the striae punctate, first 

 four dorsal equal, entire, the fifth and sutural equal, abbreviated anteriorly 

 before the middle, subhumeral anteriorly very much abbreviated. Epipleurae 

 impunctate, bistriate. Pygidium rather scatteringly punctured. Feet brown- 

 ish antic tibiae 5-toothed. Long -1. 



Phelister marginellus. Ovalis marginatus, convexus, rufus, niti- 

 dus impunctatus, fronte concava ; pronoto stria marginali integra, ambiente ; 

 elytris striis impunctatis, dorsalibus quatuor primis integris, aequalibus, quinta 

 et suturali ante medium antice abbreviatis, subhumerali integra. 



Maryland. 



Oval widely margined, convex, rufous, shining, impunctate ; front excavated. 

 Margin of the thorax projecting and containing the marginal stria which is 

 entire and ambient and leaves a narrow raised cushion on the fore part. Ely- 

 tra with the first four dorsal striae entire and equal, the fifth aud sutural ab- 

 breviated anteriorly before the middle, all of them impunctate, subhumeral 

 entire, placed on the margin. Pygidium punctate ; antic tibiae indistinctly five- 

 toothtd. Length "1. 



Phelister Panamensis. Ovalis, convexus, piceus, nitidus, fronte leviter 

 concava ; pronoto ad latera puncticulato, estriato ; elytris striis dorsalibus 

 quatuor primis integris, quinta et suturali abbreviatis, stria subhumerali antice 

 abbreviata, pygidio dense punctato* 



Panama. 



Oval, convex, pitchy, shining, front lightly concave : thorax puncticulate on 

 the sides, without a stria, marginal stria entire. Elytra with the four first dorsal 



1859.] 



