June 1899.] CASEY : On AMERICAN COCCINELLID^E. 121 



two sexes frequently differ in coloration. In adopting type of colora- 

 tion as a primary taxonomic character however, this is restricted be- 

 low to the patterns of the elytra, as sexual divergencies in ornamenta- 

 tion are almost exclusively confined to the head and prothorax, which 

 are very often in part pale in the male and entirely black in the fe- 

 male. In fact this seems to be the only possible means of distinguish- 

 ing the males from the females, as the external structure of the ab- 

 dominal apex is very nearly similar in the two sexes. The species are 

 numerous and those known to me may be distinguished as follows : — 



Body very broadly rounded and strongly convex 2 



Body elongate-oval or oblong-oval and frequently more depressed 15 



2 — Elytra black, with a pale red margin not attaining the sutural angles and with 



which a rounded discal spot is broadly confluent a little behind the middle ; 



elytra strongly and moderately closely punctured. Length 3.0 mm. Illinois. 



bolterl Lee. 



Elytra black, with three marginal or submarginal pale spots 3 



Elytra black, with a short marginal vitta from the humeral angle, a submarginal oval 

 or rounded spot near the apex and another at or near the middle and near inner 

 third of the width, the latter obsolete in var. omissa 4 



Elytra black, with a single marginal or submarginal spot far behind the middle or 

 near the apex 7 



Elytra black, with two marginal or submarginal pale spots, the anterior of which is 

 not basal 8 



Elytra black, without marginal or submarginal spots but with a single spot near or be- 

 hind the centre of the disk IO 



3 — Black, shining, finely but distinctly punctate, the pronotum closely, the elytra 

 rather sparsely ; head black, the pronotum with a quadrate lateral spot almost as 

 wide as long ; elytra with a humeral marginal vitta between two and three times 

 as long as wide in less than basal third, an internally rounded marginal spot just 

 behind the middle, a rounded subapical spot equidistant from the margin and 

 suture and a spot on the disk at basal two-fifths and inner third or fourth, which 

 is rounded but with its anterior edge broadly sinuate ; legs black, the tibire and 

 tarsi pale, the posterior tibioe blackish ; sides of the abdomen narrowly reddish. 

 Length 2.8 mm. ; width 2.2 mm. Arizona 8-notata, sp. nov. 



Black, shining, the pronotum finely and not very closely punctulate, the elytra more 

 strongly and quite sparsely punctate ; head pale, the basal third black ; pronotum 

 with a very narrow parallel pale side margin ; elytra with a very small narrow 

 humeral, and a slightly larger but narrow and parallel post-median, yellow spot, 

 and a large subapical spot nearer the margin than the suture, also with a small 

 elongate-oval spot just before the middle and at inner two-fifths ; legs pale pice- 

 ous, the hind thighs darker ; abdomen not visibly pale at the sides. Length 2.15 

 mm. ; width 1. 55 mm. Nevada (Reno) notatula, sp. nov. 



4 — Humeral vitta very narrow and inwardly prolonged along the base for a short dis- 

 tance, terminating posteriorly just before the middle ; male with the head and a 



