the thin, outer bark, which had apparently lieen broken by the wind. 

 These pieces coniained a larva, evidently of the same species as those 

 previoLislv observed ; and similar larvte, but no pupa?, were observed in 

 the prostrate stems, on the 25th of the followin--; April. From these ob- 

 servaticMis, Mr. Coquillett opmed that the beetles deposited their eggs in 

 mid summer ; the hivvat;, hatching in a few days, reached tlieir full growth 

 in three or four months, and, hibernating in the stems in that stage, chang- 

 ed to pupa? early the following Summer, emerging as adults soon after. 



At the time Mr. Coquillett was making these observations, we, in 

 an adjoining County of the same State, were similarly engaged, although 

 as Ignorant of his studies as he was of ours. However, with the exception 

 of securing more facts relative to the mode of oviposition, and the number 

 of eggs, and the grouping o( the egg chambers, we did not materially im- 

 prove upon his observations, as afterwards published. 



In Northern Illinois, where we always found 7nacer to be the hiost 

 common species of Z/av/.s. co;/C(ro«.s seldom occu red in our collections. 

 In Central Illinois, in 1882 and 1883, we found the latter to be the more 

 abundant species, while the former was seldom observed. We were more 

 surprised to here observe concavus ovipositing in the stems of Helian/hus, 

 exactlv as we had observed its congener do in the Northern part of the 

 Slate. 



The female, of either species, in depositing her eggs, first places her- 

 self, head downward, upon the sialk in which she intends to oviposit, 

 and, wuliout moving the feet, commences a series of l>ackward and for- 

 ward movements of the rostrum, gouging out a narrow channel, varying 

 from three-fourths to about an inch in length, penetrating through the 

 woodv portion of the siem to the pith. This channel is not clean cut, 

 but is, when finished, filled with matted fibre, not detached and not easily 

 removed. From near the upper end of this channel, the female next ex- 

 cavates a burrow, of the diameter of her rostrum, directly into the pith, 

 for a considerable distance; thence upward as far as she can reach. 

 While we have never observed the sexes in coi/u, nor the placing of the 

 egg, the male is almost invariably present in situ, and we have often 

 interrupted the female in the midst of her work, and found an egg partly 

 in place in the stem. These observations leave little room for doubt that 

 the eggs are fecundated just prior to the act of oviposition, and dropped 

 bv the female at the mouth of the burrow, being afterwards pushed in 

 place by aid of her rostrum. 



Wherever there was good evidence of the nidus having been com- 

 pleted, we have always found a second chamber or burrow, at the lower 

 extremitv of the channel also, but not extending far enough upward to 

 come in contact with the upper. In each of these chambers we have 



