ON SILK-PRODUCING BOMBYCES. 123 



collected at some distance from Salt Lake City, Utah ; they are 

 found on narrow-leaved willows growing in or near swamps. 



The reverse has taken place with respect to Ceaiiothi cocoons 

 from California, which in 1880 were fine and large, while in 1881 

 hardly any cocoons could he collected, and these only about half 

 the size of the Ceanothi cocoons of the j^ear 1880. I regret to 

 say I have not received any Ceanothi cocoons this year, at least 

 up to the present time. 



In 1880, for the first time, I attempted the rearing of Attacus 

 Atlas from ova which were sent to me by a French correspondent 

 about the middle of August. The season being then too far 

 advanced to give me any chance of success for rearing the larvse, 

 1 only kept twelve ova to see what would come of them. Of the 

 twelve ova, five larv£e hatched on the 22nd August ; three died in 

 the first or second stage, but two lived on the barberry, under a 

 bell-glass and in splendid condition, up to the 6th November, 

 when I sent them to a correspondent for preservation. The 

 larvae had remained thirty-two days in the fifth stage, which is 

 the last but one. From this experiment, I think Attacus Atlas 

 is a species easy to rear. 



Attacus Aurota. — In 1880 I for the first time received live 

 cocoons of this splendid species (the South American Atlas) from 

 French Guiana. The moths emerged in splendid condition from 

 the 12th June to the 3rd July, but no pairings could be obtained, 

 the weather being unusually cold, as it has been observed. Moths 

 and specimen cocoons of Attacus Aurota may be seen in the In- 

 sectorium of the Westminster Aquarium, where they may be 

 compared with Attacus Atlas. 



Attacus Aurota in French Guiana has six generations in the 

 year; the larvse form their cocoons twenty days after their 

 hatching. Another species found in French Guiana, Attacus 

 Hesperus, is only fifteen days from the hatching of the larva to 

 the formation of the cocoon. Attacus Aurota and Hesperus, both 

 very brilliant species as perfect insects, produce cocoons of good 

 silk, but they are, like Atlas, Cynthia, and many other species, 

 open at one end. I hope to receive cocoons of tbese two species 

 for this season, and if so, I hope also to have some success with 

 the pairings. The difiiculties to reproduce exotic species in this 

 country are very great and various. Sometimes the moths 

 emerge too late, sometimes too early, as it has been the case this 



