384 Annals Entomological Society of America [Vol. XII^ 



above the surface of the ground at which the cells are placed 

 varies from a few inches to seven feet or higher however, one 

 to two feet is nearer the average. 



Unlike the preceding species, Chlaeniiis aestivus, while 

 often living in the same habitat as C. impunctifrons, rarely 

 ever constructs her mud or clay cells on leaves. In the habitats 

 studied, they were found almost exclusively on dead twigs, 

 plant stems and the bark of trees and shrubs, the dead thorns 

 of Gleditsia were much used in one habitat and in another 

 locality they were occasionally found on the strands of a barbed 

 wire fence. They are sometimes placed ten feet above ground. 



The cells of C. aestivus (Plate XXXI, Figs. 1 and 2) are convex 

 and oval in form, coarsely granular or rough in surface; length 

 3.75 to 4.5 mm., width 2.75 to 3 mm. The exit of the larva 

 is effected by the breaking off of the lidlike flap, which covers 

 one side of the cell. 



The earthen egg cells of Chlaenius cericeus (Plate XXXI , Fig 4) 

 are smooth in surface, 3.75 mm. in length, 2 mm. in width. 

 In general shape they are somewhat triangular or purse shaped. 

 The cells of this species have not been observed in nature, 

 but in captivity the beetles placed their cells on stones and the 

 lower parts of dead plant stems, all very near the surface of the 

 moist soil. 



The cells of Chlaenius tricolor are small, measuring about 

 2 mm. in length and 1.25 mm. in width. They are strongly 

 rounded, oblong in outline, smooth in surface and along one 

 side there is a distinct fold or flap which marks the point of 

 closure. This species constructs her cells of fine clay-sand. The 

 stems of slender grasses and sedges seem to be most frequented 

 by the beetles. Cells were found in great abundance along 

 the shore of the Susquehanna River at Harrisburg, Pa., on the 

 common sedge Eleocharis tenuis. 



Construction of the Mud Cell. 



As far as the writer is aware, no one has yet noted how these 

 cells are made. This has been observed by the author, but 

 will be only mentioned in this preliminary note, it sufficing to 

 state that the pellet of mud is collected by the beetle at and 

 around the tip of the abdomen in such a way that the cell 

 formed is in reality a mold of the caudal abdominal segments; 



