OF WASHINGTON. 131 



Prof. Riley said that most were taken in the Beaver dens or 

 houses, which always contained a mass of material which 

 might attract the insects in question, and they were sifted 

 either from the material of the nest or the earth underneath 

 it. He said that the dens and nests were commonly con 

 nected with the banks of the stream under water, and with 

 the air at some other generally hidden point, thus affording 

 opportunity for the entrance of the insects, or that these 

 might also be introduced with the material used in the con 

 struction of the den. With reference to the pupa of Platy- 

 psyllus he said that he was forced to the opinion that this stage 

 is passed underground, in which belief Mr. Schwarz coincided. 



Prof. Riley said, also, that the Mallophagan and the mites 

 were found on the beavers themselves. 



Prof. Riley also called attention to the Minutes of the Pro 

 ceedings of the lyondon Entomological Society for October i, 

 1890, as published in the Entomologist* s Monthly Magazine for 

 November, 1890, and elsewhere. It is there stated that Mr. 

 C. J. Gahan exhibited a "curious little larva-like creature " 

 found in the mountain streams of Ceylon, and that there was 

 a discussion as to what the larva was. From the brief charac 

 teristics- given by Mr. Gahan it struck Prof. Riley that the 

 larva referred to is that of some species of the Dipterous family 

 Blepharocetidce : He stated that good figures of a South Ameri 

 can species, genus Paltostoma, have been published by Fritz 

 Mueller, and that he (Prof. Riley) is familiar with the larvae 

 and pupae of two North American species and has for many 

 years had drawings of the same, which are not yet published. 



He also called attention to an article in Entomological News 

 for October last, in which, under the head of ' ' What can it 

 be?" Mrs. Julia P. Ballard, of Easton, Pa., describes a larva 

 which has puzzled her because, while having some of the 

 characteristics of Citheronia regalis^ with which she is quite 

 familiar, it nevertheless materially differs from that species. 

 Her description leaves no doubt that the larva which so puz 

 zled her was that of the only other congener, namely, Cithe 

 ronia sepulchralis . This larva is not uncommon in the vicinity 

 of Washington and along the lower Potomac, where it feeds 



