OF WASHINGTON. 241 



pear that the natural history of L. sayi differs in some import 

 ant points from that of L. trilineata as described by Dr. Harris. 

 In the latter species the eggs are laid in groups, and the larvae 

 do not bore but live openly on the leaves. 



Mr. Schwarz exhibited specimens of a Monommid bet-tie 

 found by him on dead branches in the semi-tropical forest 

 along the shores of Biscayne Bay, Florida. The species differs 

 at once from Monomma and Hyporhagus by its two-jointed 

 antennal club and the form of the antennal groove, which is 

 semi-circularly curved and confined to the anterior portion of the 

 thorax. The eyes are contiguous, at least in the male, and the 

 elytral epipleura grooved for the reception of the hind femora. 



From a careful study of Dr. Champion's description of the 

 Central American Aspathinfes ovatus, Mr. Schwarz felt con 

 vinced that the Floridian species did not differ therefrom, not 

 even specifically. 



Mr. Schwarz also read the following paper : 



TIME OF FLIGHT IN LACHNOSTERNA. 



BY E. A. SCHWARZ. 



The genus Lachno sterna has of late years often been discussed 

 before our Society, and the strictly nocturnal habits of these 

 May beetles frequently been referred to. In fact, I have never 

 heard that any of our numerous eastern species leave their sub 

 terranean retreats before it gets quite dark. Thus, here around 

 Washington they do not commence to fly before 8 o'clock in the 

 last week of April, not before half-past 8 a fortnight later, and 

 so on. In 1875, while in camp at Haulover Canal, in Florida, 

 I had occasion to observe Lachnosterna <zmula, which in the 

 earlier part of March was flying about after dark, but also in 

 the early morning, when it was still so dark that the flying 

 beetles could only be heard, but not seen. Some of our more 

 northern species may possibly have the same habit, but no ob 

 servations are on record so far as I am aware. Another species, 

 L. crassissima, was observed by me on June 13, 1878, flying in 

 great numbers over the prairie at Plum Creek, Nebraska, shortly 

 after sunset, when the beetles could still be plainly seen ; in 

 other words, about one hour earlier than our eastern species. 

 This slight deviation in habit is probably caused by the dif 

 ference in the food-plants. Our eastern species feed, so far as 

 known, only on the foliage of trees and shrubs, while this 

 species must feed on grass or some other low herbage, for there 

 were neither trees nor shrubs for several miles around the spot 



