The Pselaphid^ of North America. 37 



T. coNVEXULUM, Lcc, Deep yellow, very convex, more 

 slender than the other species, pubescence not visible: body 

 impunctate, highly polished- Length 0.7 mm. Plate XL, 

 Fig. 94. 



Head nearly as wide as the prothorax, frontal margin arcu- 

 ate between the antennse, width across the tempora one-fourth 

 less; foveae and sulcus deep, the latter dilated in front; occi- 

 put carinate. Antcnnce^ from the base of the first joint to that 

 of the last, as long as the head, last joint about half as long, 

 oval, three-fourths as thick as long, with short pubescence. 

 Palpi with the last joint more oval, oblong. Prothorax long- 

 er than wide, sides sinuate near the base, the transverse sulcus 

 deep, slightly and very broadly angulated in the middle, lateral 

 foveje none. Elytra convex, bifoveate at the base, the ele- 

 vations between them not so high as in dtibiiim. Abdomen as 

 in dtibium, but the first dorsal segment is much longer than 

 the second, with two short basal carinas and lateral basal de- 

 pressions as in Batrisus. The fourth and fifth dorsals are 

 connate, the contiguous limits scarcelv discernible: ventrals 

 correspond in length with the dorsals. Legs slender. Sexual 

 differences of the clypeus as in diibium. 



Habitat. Illinois, Pennsylvania, Florida. 



This species answers better to the description of the genus 

 Trimiiim than the others, if we assume as characteris- 

 tic the length of the abdominal rings, while all the other 

 species would coincide with Mr. Reitter's genus Trimiopsis. 

 Dr. Sharp considers Triviimn and Triiniopsis as hardly dif- 

 ferent. 



T. DUBiUM, Lee. Deep vellow, verv convex, nearly circular 

 in transverse section, no pubescence visible. Surface, except- 

 ing the head, smooth and polished. Length, i.oo mm. Plate 

 XL, Fig. 95. 



Head of the form of parvuliini, except in the frontal margin 

 being obtusely angulate; punctulate, no occipital impression; 

 the foveae large but not deep, the sulcus fine in some speci- 

 mens, deeper in others, and slightly foveolate next to the 



