101 



case to the leaf when it wishes to be stationary. When it wants to 

 change its place it comes partly out, cuts off the threads, and then 

 stretching further out, lays hold of the leaf with its true legs, and sud- 

 denly shortening its body brings up its cocoon with a jerk: in this 

 way it goes along half an inch at a time. It never voluntarily deserts 

 its cocoon, and all my attempts to make it come out without using 

 violence, were ineffectual. The cocoon sent by Dr. Melsheimer con- 

 tains the chrysalis and vestiges of the caterpillar's skin, of which only 

 the corneous head and anal plate were entire. The cocoon was closed 

 at each end by little circular pieces, of the colour and thickness of stiff 

 brown paper, one of which had been pushed off when the moth came 

 out, but still hung by a few threads. The chrysalis has, on the mid- 

 dle of the edges of six dorsal segments, a transverse row of little teeth 

 which could be shut into corresponding caAities on the surface of the 

 contiguous segments, forming six sets of nippers, which were evidently 

 intended to help the chrysalis in advancing in its cocoon, and in tak- 

 ing firm hold when engaged in pushing off the lid. The tail is trun- 

 cated or blunt, with six minute points. The form of this caterpillar 

 and the structure of its cocoon are very different from those of Oiketi- 

 cus and Psyche, and the moths, both sexes of which are winged, and 

 differ only in the structure of the antennse, cannot be referrible to either 

 Oiketicus or Psyche. I therefore propose to call the genus Saccopkora, 

 the species Melsheimeri. 



" Will not tliis singular and interesting insect remove some of your dif- 

 ficulties respecting the transition from Psyche to Bombyx ? It may be 

 that it is alliedio some of the Notodontiadae,but I am wanting in several 

 genera, as Stauropus, Chaonia, Peridea, with which to compare it." 



Such is the account of this curious moth furnished me by Dr. Har- 

 ris, and such is his opinion of its position. My own is, that it is near 

 to Dryocampa, and that its Sacktrager habits only indicate an analogy. 

 In their own circle the Dryocampae appear to me to symbolize the true 

 Oiketici, as Oi. Kirbii, and perhaps Abbot's insect ; a fact made evi- 

 dent, I think, by the form of the male Dryocampa?. The habits of this 

 new insect and its affinity to Dryocampa, especially Dry. rubicunda, 

 support this supposition. What if we find Sacktragers in each natu- 

 tural division of the Linnean Bombyces ! Three 1 imagine we have 

 them in already. 



Edward Doubleday. 



