38 THE CANADIAN ENTOMOLOGIST. 



tentacles concealed within 12, as in the species mentioned, though I had 

 no opportunity to see them active ; head minute, obovoid, dark brown, 

 placed on the end of a long, conical neck. 



Chrysalis. — Length, .22 inch, breadth at mesonotum, .06, at abdo- 

 men, .09 inch ; shape elliptical ; the head case rounded and truncated 

 somewhat ; the mesonotum slightly prominent, rounded at tip, no.t cari- 

 nated, the sides a little convex, followed by a slight depression ; abdo- 

 men somewhat tumid ; colour yellow-white, with a pink tint over the head 

 case ; surface sparsely and irregularly dotted black, with two sub-dorsal 

 rows of larger dots of same hue from 5 to i 2. One pupa from the three 

 larvae gave imago 14th August, but as I had omitted to note the date of 

 pupation, I am unable in this case to give the duration of the stage. 

 But another pupa of those formed in route gave imago 29th July, and 

 as it had been mailed on the 22nd, I conclude the stage must endure 

 through six or seven days. 



Mr. Cockerell wrote 22nd July: — " Yesterday, walking to the Agricul- 

 tural College, I found a bush with ants running in numbers over the 

 twigs. Looking to see what they were after, I came across a larva and 

 then another. Presently I saw that the bush was swarming with them, 

 only they were so perfectly concealed by their colour that I should not 

 have noticed them except for the ants. They (the larvae) were little and 

 big and quite exposed to view. On same bush were many Coleopterous 

 larvae in their cases, and flying about the bush were many of the Exilis 

 butterflies." Some of the ants were sent me with a supply of the flowers, 

 and they were tiny creatures. 



In letter of 29th July : — " Yesterday I saw a female Exilis deposit an 

 egg ; she thrust it under a flower on the outside. I had to look very 

 closely to find it, even after seeing it laid. The egg is circular, seen from 

 above, flat, greenish-white." 



Dr. Boisduval described Exilis, in 1S52, from a female, which he 



says is the only example of the species he has seen ; and speaks of it as 



one of the smallest Lycaenae known. The male is considerably smaller 



than the female, and I think may be the smallest butterfly in the world. 



Notwithstanding its littleness, it flourishes in southern California, Arizona, 



New Mexico, parts of Colorado, Texas, and has even reached Florida. 

 Mr. Cockerell wrote me 9th December: — '■'■Exilis is still in the imago 

 here. I caught one to-day at rest on the stalk of a Solanum. Is it 

 possible that they hibernate as butterflies ? We have had plenty of frost, 

 though no snow as yet." 



