88 GEO. H. HORN, M. D. 



internal lobe corneous. Anterior tibise tridentate, middle and poste- 

 rior tibiie with feeble trace of oblique ridges. Tarsi slender, the first 

 joint of the posterior elongate. 



This genus is now almost universally admitted, although Thomson 

 (Skand. Col. v) places the only species known to him in Psammodius. 

 It seems, however, intermediate between Attenius and Psammodius. 



All the species known to me have the lateral margin and base fim- 

 briate with clavate spinules, in Psammodius they are simple hairs. 

 As the character is common to all it is omitted in the description. 



Our species are sei:)arated as follows : 



Clypeus obtuse or rounded each side of emargination. 

 Intervals of elytra with a row of small tubercles on the inner side, a continu- 

 ous, finely elevated line on the outer seaber. 



Intervals with two rows of tubercles ealitbriiictis. 



Clypeus angulate or subdeutate on each side. 



Intervals with a double row of nearly equal tubercles, vertex simple. 



soiiatu!^. 

 Intervals with a series of elevations, each tubercle with a scale-like hair, ver- 

 tex with a transverse elevated line riparius. 



The elytral sculpture is often very difficult to appreciate, and it is 

 only by good, clear daylight that any description can be made with 

 accuracy, but with artificial light under the power of a compound 

 microscope very deceptive results are obtained. 



RIi. st*aber Hald. — Oblong, niodei'ately convex, piceous opaque, legs brown- 

 ish. AuteunfB pale. Head moderately convex, granulate, the granules coarser 

 at middle and in front, denser, finer and more opaque posteriorly. Clypeus mod- 

 erately emarginate at middle, the angles rounded, sides arcuate, gense very ob- 

 tuse. Thorax one-fourth wider than long, slightly narrowed in front, anterior 

 angles obtuse, sides arcuate, lateral margin not distinctly crenulate, hind angles 

 broadly rounded, ba.se arcuate with distinct marginal line, disc convex, densely 

 granulate, with four discal equidistant transverse rows of larger tubercles, the 

 anterior two entire, the posterior two interrupted, these larger tubercles more 

 shining. Elytra as wide as the thorax, humeri slightly dentate, sides slightly 

 arcuate, strise fine, indistinctly catenulately punctured, the intervals with a row 

 of elongate tubercles placed closely and slightly oblique on the inner side, a more 

 elevated cariniform line on the outer side which is entire anteriorly, interrupted 

 posteriorly. Mesosternum opaque, densely punctured, finely carinate between 

 the coxse. Metasternura smooth. Abdomen nearly smooth, the segments crenate 

 in front, each with a transverse row of serrate punctures at middle. Posterior 

 femora smooth, the marginal line fine and entire, first joint of hind tarsus nearly 

 as long as the next three. Length .14-. 16 inch ; 3.5-4 mm. 



In this species the thoracic sculpture has the most perfect develop- 

 ment of any in our fauna, the transverse carinse are well marked and 

 the granules larger and more shining than those of the interspaces. 



