THE CANADIAN ENTOMOLOGIST. 113 



has found an abundance of suitable food. But my opinion is, that in the 

 majority of cases it is a matter of sexual importance, and but for this 

 powerful influence which causes them to seek each other, and thereby 

 propagate their species, these most beautiful objects of nature would 

 eventually die out. 



NOTES ON THE PREPARATORY STAGES OF CARTERO- 

  CEPHALUS MANDAN. 



BY JAMES FLETCHER, OTTAWA. 



Amongst some fertile eggs of butterflies obtained during the past 

 summer by gently pressing the abdomen of ripe females, was one of 

 the above species, the larva of which was carried through four moults up 

 to hibernation, The information gathered is incomplete ; but as there iS 

 nothing published concerning the preparatory stages of C. Mandan, it 

 seems worth recording, if only to assist others who may be fortunate 

 enough to secure eggs of this rare butterfly. Although widely distributed, 

 over North America, I know of no locality where it is abundant. Females 

 taken at Nepigon in the Lake Superior district laid eggs in confinement 

 upon common lawn grass ( Poa pratensis). 



. The following description is drawn from one specimen only for the 

 last two stages, but from three for the first three stages : — 



£gg. — Pale greenish white, hemispherical, broader than high, appar- 

 ently smooth, but when magnified found to be very faintly and vertically 

 grooved or wrinkled, and densely and uniformly pitted with deep pores 

 which are wide at the mouth and taper to a fine point. Eggs laid 13th 

 July, hatched 23rd. 



Larva, — At birth. Length 2.5 mm. Breadth of head, .45 mm. ; of 

 body, .35 mm. Length of bristles, .05 mm: Yellowish white, with head, 

 and thoracic shield black. Head large and smooth. Body slender, 

 equal. Thoracic shield narrow and bearing a few slender hairs. Body 

 bearing on each side four series of trumpet-shaped bristles. Duration of 

 first stage five days. 



From the very first these larvae were great wanderers, frequently leav- 

 ing their food plant and crawling all over the glass lamp chimney which 

 was used as a cage. In these wanderings they spun silken paths wherever 

 they went, and to prevent their escape a plug of cotton wadding wag> 



