THE TUMBLING FLOWER BEETLES. 1309 



separating- the genera and species is the number and form of the 

 small black ridges on the outer face of the hind tibiae and tarsi. The 

 insects sliould be mounted Avith the hind legs straightened out and 

 plainly \'isible, else their identification is impcssible. 



KEY TO INDIANA OENERA OF MORDELLID.E. 



a. Abdomen not prolonged at tip ; tarsal claws not cleft ; upper surface of 

 body very finely and transversely strigose. 

 h. Front and middle tarsi with third and fourth joints equal ; antenuse 

 rather short, with the last five joints broader. I. Pextabia. 



hb. Front and middle tarsi with the fourth joint very small. 



II. Anaspis. 



an. Abdomen with the last segment prolonged, conical ; tarsal claws cleft 



and pectinate ; hind femora much enlarged. 



r. Hind tibite with only a small subapical ridge ; eyes finely granulated. 



(1. Anal style short, obtuse ; scutellum usually emarginate behind ; 



eyes not reaching the occiput. III. Tomoxia. 



(Id. Anal style long and slender ; scutellum triangular ; eyes reaching 



the occiput. IV. Mordella. 



cc. Hind tibiiE and tarsi with oblique ridges on the outer face; eyes 



coarsely granulated. 



V. Hind tibise with one long ridge and no subapical one (Fig. 57(i. No. 



10) ; length i;-8 mm. V. Glipodes. 



cc. Hind tibi;e with subapical riilgc distinct and usually one or more 



oblique ones in addition (Fig. .570, Xos. 1.5 and 17> ; length less 



than (j mm. VI. Mokdellistexa. 



I. PEXT.A.EIA Muls. 1856. (Gr., "five + thin.") 



Our species of this and the next genus are small yellow or yellow 

 and black, finely pubescent forms, having the body fusiform rather 

 than wedge-shaped; hind femora not or but slightly dilated; last 

 dorsal segment not prolonged; eyes oval, narrowly emarginate. 

 Pen f aria has the sixth ventral segment visible, and is represented in 

 the State by one of the four known species. 



241S (7701). Pextaria trifasciata Melsh.. Proc. Phil. Acad. Xat. Sci.. II, 

 1845, .316. 



Elongate, subdepressed. Head, thorax, legs and base of anteuniE dull 

 reddish- yellow ; elytra yellow, with base, tips and a broad band just behind 

 the middle, black ; abdomen, and sometimes the entire under surface, fus- 

 cous. Length 3-A mm. 



Throughout the State, f rerpient ; more so in the southern coun- 

 ties. June 1-July 30. Occurs on flowers, es))ccially those of the 

 dogwood {Cornus), wild hydrangea and black haw. The thorax is 

 sometimes marked with fuscous and the bands of elytra are rarely 

 connected along the suture. 



