ENTOMOLOGY. 1063 



worthy as indicating origin, in some instances, on account of the uncer- 

 tainty arising from the action of the principle of retardation, on the one 

 hand, and acceleration, on the other, in the forming of new broods.' 1 



A consideration of the validity of the old records hearing on the distri- 

 bution of the broods of the periodical cicada, with particular reference to 

 the occurrence of Broods VI and XXIII in 1898, C. L. Marlatt (pp. 59- 

 78). — The author gives the result of an investigation which was under- 

 taken to determine the distribution of Brood XXIII of the 13-year race 

 and of Brood VI of the 17-year race. Circular letters were sent to sev- 

 eral thousand correspondents, and from the replies the distribution of 

 these broods has been outlined by counties and localities much more 

 definitely than has heretofore been done. 



Some observations on the cycle of the sexual development of the blood 

 louse (Schizoneura lanigera), 8. Mokrzhet&M (pp. 78-81). — This paper 

 contains biological details of the life history and development of this 

 insect, together with notes on the means of transportation of the insect 

 from one locality to another. 



A cecidomyiid injurious to seeds of sorghum, D. W. Coquillett (pp. 81, 

 82). — Seeds of sorghum which were received from the Texas Station 

 were found to be infested by an insect which upon examination proved 

 to be a new species and is described by the author under the name of 

 Diplosis sorghicola. In the seeds which the Department received these 

 insects were very numerous, and the only parasite which was noticed 

 upon them was the genus of Chalcis flies known as Apostrocetrus. 



A leaf tier of grape and elderberry, F. E. Chittenden (pp. 82, 83). — The 

 author relates that in the summer of 1897, at Colonial Beach, Virginia, 

 he noticed numbers of the larva? of a pyralid moth which had the 

 habit of folding the leaves of grapes together and joining them with a 

 sort of web. When reared, the moth proved to be Phlyotcenia tcrtialis. 

 Later investigations disclosed the fact that the same species lives upon 

 the elder and has the same habit upon that plant. The species is 

 recorded from Maine, New Hampshire, Massachusetts, Xew York City, 

 Pennsylvania, Ouaga, Kansas, and Colonial Beach, Virginia. 



A flea-beetle living on purslane, F. R. Chittenden (pp. 83-85). — At 

 Marshall Hall, Maryland, the author found eggs of the flea-beetle which 

 when reared proved to be those of Disonycha caroliniana. The larvse 

 of the beetle feed upon the common purslane, Portulaca oleracea. A 

 technical description is given of the larva and pupa. Both the larval 

 and pupal forms are said to resemble very closely another species of 

 the same genus, D. xanthomelana . 



Cotton-field insects (pp. 85-88).— A correspondent of the Division 

 having set out three trap lanterns for one night near Victoria, Texas, 

 forwarded for examination the insects which were taken. In all the 

 catch contained 24,492 specimens, representing approximately 328 spe- 

 cies. The injurious species numbered 13,113 specimens, the benefi- 

 cial 8,262 specimens, and those of a negative character 3,117 specimens. 

 The object of the experiment was to determine whether the Mexican 



