66 Journal New York Entomological Society. [Vol. xvi. 



This species is very near binotatus Fall, but differs in the shorter 

 and wider third, fourth and fifth antennal joints and the immaculate, 

 shorter thorax, with broadly reflexed sides near hind angles. 



The female differs from the above described male, in having the 

 lateral margin entire, feebly sinuate, and shorter and slightly stouter 

 antennal joints. 



Silis nigerrima, new species. 



Black, finely pubescent with short, cinereous hairs, which are longer on the 

 thorax than elytra. Head minute and sparsely punctured. Antennas slender ; thorax 

 very sparsely, minutely punctate, apical margin broadly arcuate ; disk shallowly de- 

 pressed at middle. Elytra not coarsely punctate, at the extreme base very finely and 

 densely punctate ; costae scarcely evident. Body beneath pubescent with longer cine- 

 reous hairs than on elytra. Length 11-12 mm. 



Male. — Antennae longer than the entire body ; joints clothed rather densely with 

 short, prostrate, pale pubescence. Thorax with two broad lateral processes ; the 

 apical process is directed backwards, almost touching the basal process with its apex, 

 which is bent slightly upwards ; the basal process is laterally compressed and slightly 

 excavated near apex ; below the posterior process the lateral margin is arcuate-eniargi- 

 nate from the process to the basal angles, which are obtuse. Penultimate ventral seg- 

 ment broadly, triangularly emarginate ; last ventral, as usual, longitudinally divided. 



Female. — Antennae slender, but shorter than the body. Thorax transverse, 

 apical margin broadly arcuate, continuous with the side margin ; sides very distinctly 

 sinuate slightly before middle and feebly so before basal angles, which are obtuse 

 and very feebly rounded. Last ventral segment broadly rounded. 



Huachuca Mts., Arizona. 



The black color, the lateral thoracic processes of the male, which 

 are somewhat similar to those of perforata Lee, and the form of the 

 female thorax makes this an easily recognizable species. The Mexican 

 lalicollis Gorh., which is also black and has the male thorax similarly 

 formed, is a shorter and more robust insect, with wider thorax, shorter 

 antennae and with last abdominal segment flavous. 



Silis abdominalis, new species. 



Black, front of head, the first two joints of antennae, scutellum, legs, except tarsi 

 and apex of hind tibiae, sides of abdominal segments and the last two ventral seg- 

 ments reddish. Head finely punctate and sparsely pubescent. Antennae slender. 

 Thorax almost impunctate ; apical margin broadly arcuate. Elytra rather coarsely 

 punctate, costate and feebly pubescent. Body beneath more evidently pubescent than 

 the elytra. Length 5 mm. 



Male. — Antennae not quite as long as the entire body, joints elongate, with very 

 feeble pubescence. Thorax with two broad lateral processes ; the apical process is 

 directed backwards, short and somewhat truncate at tip; the basal process is broad, 

 feebly narrowing to apex, where it is feebly emarginate ; below the posterior process 

 the lateral margin is very feebly emarginate ; hind angles rather acute. Penultimate 



