THE TUMBLING FLOWER BEETLES. 



1317 



2436 (7796). Mokdellistena arida Lee, Proc. Phil. Acad. Xat. Sci., XIV, 

 1862, 48. 

 Larger aud slightly darker than lutea. Ridges of tibije and tarsi longer 

 and stronger than there, those of the first joint of hind tarsi much more 

 oblique. Length 3.5-4 mm. 



Lake, Porter and Tippecanoe counties; scarce. June 27-July 

 21. The specimens from Lake and Porter counties were taken from 

 the flowers of the prickly pear cactus, Opuntia rafinesquii Bngelm. 

 Both LeConte and Smith state that 

 aiicla has but two ridges on first joint, 

 but all the specimens at hand have three. 

 Dr. Smith pronounces them arida, stat- 

 ing that "the difference in the ridges is 

 within the range of variation. ' ' This is, 

 of course true, but how about the keys, 

 which are based on an unvarying num- 

 ber of ridges? 



^tRot't* O 



Fig. 577. a, Hind tibia and tarsus of 



In this group the tibitC bear two MorMMtai fr.7a«ciato; t, elytron ot same; 



° ' t, elytron of M. hwbalts. (After Smith.) 



equal oblique parallel ridges on the 



outer face. (Pig. 577, a.) The following species have been taken 



or should occtu* in Indiana: 



KEY TO INMAX.S. Sl'EUIES OF GKOl P C, 



a. First joint of hind tarsi with two oblique ridges. 



h. Second joint of hind tarsi with but one oblique ridge. 



o. Elytra black with two transverse yellow bands, the front one part- 

 ly interrupted at suture l)y a prolongation of the black band at 

 base. 

 <L Body black ; thorax black with basal margin and sides dull yel- 



j(^^ 2437. TKIFASCIATA. 



0(1. Body yellow ; thora.x yellow with a faint fuscous cloud on disk. 



2438. LEPIDUI.A. 



vc. p:iytra without transverse yellow bands. 

 e. (.'olor above wholly or in gi'eat part pale. 



f. Thorax with front angles and a large spot on center of disk 



]j]a^(;]j 2439. LiMBALis. 



//. Thorax and elytra wholly pale clay yellow. 2440. vapida. 



ec. Color above wholly or In gi-eat part black or pieeous. 



g. Elytra with a reddish-yellow oval humeral spot. 



2441. biplagiata. 

 fHI. Elvira without distinct humeral spot. 



h. Head, thorax and Ic^'s, except the hind femora, reddish-yel- 

 low. DIMIDIATA. 



