72 TRANS. ST. LOUIS ACAD. SCIENCE. 



Genus CRYPTUS, Fabr. 

 Section i, Cresson. — "Scuteland abdomen black." 



Cryptus robustus, Cress. — 9. — Mr. Cresson correctly remarks 

 of the $ that "joints 2-4 of the four anterior tarsi are short [equi- 

 laterally] triangular, dilated and spinose, which seems to be an 

 important character of the species." (Proc. &c. iv. p. 265.) 

 Judging from the analogy of % 9 Labena, Cress., where the hind 

 tarsi of % are normal and those of 9 abnormal, I should infer 

 that this is a mere sexual character peculiar to $ . I have no 

 doubt, judging from the descriptions, that Cr. crassicorm's, Cress, 

 is the 6* of robustus, as doubtingly suggested by Mr. Cresson 

 {Proc. &c. iv. p. 265), and nothing is said as to its tarsi being 

 abnormal. Eight ? from Colorado, collected by Dr. Velie. 



Section 2, Cresson. — " Scutellum pale; abdomen black." 

 Not represented. 



Section 3, Cresson. — " Scutellum with pale markings ; ab- 

 domen red, or red and black." 



Cryptus atriCOllaris, n. sp.— $ .—Rufous. Head black, subopaque, very 

 finely and rather closely punctate. Wide orbits, broadly but not deeply 

 emarginate opposite the antennae, a spot on the vertex just behind the ocelli 

 which is often very minute but rarely absent, clypeus, and very often a large, 

 quadrate spot above it and separated from it only by the black clypeal suture, 

 cheeks, mandibles except their teeth, and palpi, all white. Antenna; nearly 

 as long as the body, brown-black; the 1st joint of the scape, and sometimes 

 3 or 4 of the following joints, rufous beneath ; flagellum with more or less 

 of the tip of joint 5, the whole of 6-9, and sometimes the base of 10, white 

 above and below. Joint 1 of the flagellum 6 times as long as wide, joint 2 

 shorter by \\ the rest gradually shorter and shorter. Thorax tinged with 

 yellow below and on the metathorax, subopaque, very finely and densely 

 punctate ; the parapsidal grooves distinct but not impressed ; the disk of 

 the collare on each side longitudinally aciculate. Metathorax with the nor- 

 mal areae obsolete, except the cross-carinae and the acute, thorn-like tips of 

 the lateral areas. Tegulae, a line under the front wing sometimes obscurely 

 prolonged downwards on the front edge of the mesothoracic pleura, abroad, 

 pointed line underlying the humeral suture to its very tip, a subquadrate 

 spot on the disk of the mesonotum, both scutels, and the anterior edge of 

 the collare, all white. The rest of the collare, as well as the humeral suture, 

 more or less of the depressed areas surrounding the 2 scutels, and sometimes 

 the parapsidal grooves and rarely the entire lateral lobes of the mesonotum 

 and the base of its middle lobe, all black. Abdomen oval, not much longer 

 than the head and thorax together, polished, with very fine, rather sparse, 

 shallow punctures, sometimes tinged with yellow, especially at its base ; the 

 tip of joint 1 generally more or less tinged with white. Joint 1, 2\ times as 



