8 MEMOIRS ON THE COLEOPTERA 



ii Pur pur ea group. 



This is a very large section of the genus, characterized by a rather 

 broad, moderately convex, distinctly and evenly sculptured body, 

 with moderate labrum, hairy front in both sexes, more metallic 

 and smoother elytral side-margins, well developed tarsi and rather 

 deficient maculation as a rule, this only very rarely expanding 

 along the sides to form an entire white margin as in cimarrona, 

 seen in an incipient stage in auguralis. This and the two following 

 groups exhibit a progressive posterior inflexion of the humeral 

 lunule, scarcely at all evident here, more pronounced mformosa and 

 very pronounced in tranquebarica. The forms attachable to the 

 purpurea group are purpurea Oliv., extending from the Atlantic 

 coast to the plains of Kansas but replaced by other forms in the 

 Rocky Mountains, decemnotata Say, splendida Hentz, limbalis 

 Klug, amoena, spreta, auduboni and cimarrona Lee., graminea 

 Schaupp, transversa, ludoviciana and sierra Leng, lanta and denver- 

 ensis Csy., and including some less pronounced forms, auguralis*, 

 ardelio*, franciscana*, inducta*, awemeana*, eldorensis* and alber- 

 tina*. Denverensis and sierra form a very distinct subgroup and 

 are pronouncedly distinct species, not at all closely allied to any 

 others; the penultimate joint of the labial palpi is wholly pale in 

 the male of both, which withdraws them widely from the more 

 typical species, but in limbalis this joint is also pale or piceous in the 

 male, though black in the allied awemeana. Sierra was placed 

 among the allies of tranquebarica by Leng but in my opinion in- 

 correctly. 



12 Formosa group. 



The less numerous species of this group have most of the char- 

 acters of the preceding but with a more developed labrum, except 

 in admiscens, plumper body in one section, a more convex upper 

 surface, with broad white lateral margins and more inflexed humeral 

 lunule. The various forms are formosa Say, generosa Dej., venusta 

 Lee., manitoba Leng and luxuriosa*, versuta*, gracilenta* and 

 admiscens*. Latesignata and tenuicincta placed here by Leng be- 

 long very evidently with the fulgida and willistoni series, not only 

 because of habitus but as proved conclusively by the very short 

 hind tarsi. 



