174 THE CANADIAN ENTOMOLOGIST. 



subsequent authors. The most interesting operation in the pupation of 

 the suspensi butterflies is the withdrawal of the chrysalis from the larval 

 skin, the casting off of the skin with its attachment by the terminal legs 

 to a button of silk spun for the purpose by the larva, and the attachment 

 and suspension of the chrysalis by its anal spine to the silk button. 

 Reaumur represented it as accomplished by the chrysalis in its extensions 

 and contractions grasping the larval skin between the segments, and by 

 this means raising itself until it regained the button. Recently Mr. 

 Osborne, an English Entomologist, discovered a membrane serving as a 

 suspensory agent in the change to the pupal state, and for the first, ques- 

 tioned the account given by Reaumur. His observations were confirmed 

 by those of Mr. W. H. Edwards, and followed up by additional observa- 

 tions on large numbers of Nymphalidae and Danaidas, some of which have 

 been presented in the Canadian Entomologist. There seems to be no 

 question of the existence of such a membrane, and that it consists of the 

 portion of the larval skin lining the region of the rectum, caught upon two 

 knobs conveniently placed for the purpose. Prof. Riley, in a communi- 

 cation to Psyche (vol. ii., p. 249) finds other means of chrysalis suspension 

 — the principal one being the shed intestinal canal, and accessory ones, the 

 tracheal vessels of the last pair of spiracles ; these Prof. Riley regards as 

 the principal agents in suspension. In opposition to this, Mr. Edwards 

 considers these ligaments as of but little, if any, service, and finds the 

 membrane to furnish all the requisite support. Additional observations 

 are required to' reconcile these different views. 



The beds of fossil insects recently discovered in the Tertiaries of our 

 western Territories are proving to be wonderfully rich in number of species 

 and condition of preservation. From a single small basin exposed by a 

 railway cut in the vicinity of Green River Station, Union Pacific Railroad, 

 in Wyoming, Mr. S. H. Scudder in Fossil Insects of the Green River 

 Shales (Bull. U. S. Geolog.-Geograph. Surv. Terr., iv., No. 4, pp. 747-776) 

 enumerates eighty species, representing all the orders of the Insecta 

 except Lepidoptera. An idea of the richness of these beds may be 

 obtained from the statement, that a two hours' search was rewarded by the 

 collection of fifty new species. We are glad to learn that Mr. Scudder is 

 engaged upon a general work on our fossil insects, which will form one 

 of the volumes of the quarto reports of the Hayden Survey — the beautiful 

 typography and illustration of which causes us to regret the prospective 

 speedy termination of the series. As the Tertiary Shales of the Rocky 



