THE DISTRIBUTION OF INSECTS IN NEW HAMPSHIRE. 345 



own state" (Massachusetts), is wholly erroneous. I have ascended Grey- 

 lock, the highest mountain in Massachusetts, more than twenty times, 

 and at all seasons of the year, and certainly could not have failed to see 

 this butterfly did it occur there. Since Monadnock is a naked peak, it 

 would certainly be a more propable habitat for the insect ; but the limita- 

 tion of its distribution in the White Mountains wholly forbids the possi- 

 bility of its presence on a much lower and isolated mountain to the 

 south. 



The butterfly is found most abundantly from about one quarter to three 

 quarters of a mile from the summit of Mt. Washington, or at an elevation 

 of from 5600 to 6200 feet above the sea. It often alights on the flowers 

 of Silene acaulis Linn., and also upon some of the Ericaceae, particularly 

 on a species of Vaccinium ; but the best collecting places are the sedgy 

 plateaus of the north-eastern and southern sides of the mountain, where 

 the collector will also obtain a good footing, a matter of no small 

 importance on such a collecting ground. I have never found the butterfly 

 at the head of any of the deep ravines. 



Dr. Meyer-Diir states of CE". AcHo, the species occurring in the Euro- 

 pean Alps, that it inhabits the calcareous and central mountains, — not the 

 highest chains, as has been generally supposed, but rather the middle 

 regions, from 4000 to 6000 feet above the sea.* He also makes the 

 remarkable assertion that the butterfly appears, at least in Switzerland,! 

 only on alternate years, namely, those with even numbers. Prof. Frey 

 thinks this to be true only for each special locality, but that every 

 year it may be found in some of them. 



All the species of this family of butterflies, so far as they are known, 

 feed in the caterpillar state on grasses ; % but as the true grasses are rare 

 in the inhospitable region where this insect is found, being replaced almost 

 altogether by sedges, the caterpillar feeds upon the latter. Mr. Sanborn 

 has seen them eating it by day, and, by the aid of a lantern, I discovered 



* See our previous remarks on this species, p. 343. 



f Meyer-DUr says further, that the records of its capture out of Switzerland are also in even years ; but, since 

 writing the above, I notice that Speyer, in his work on the geographical distribution of the Lepidoptera of Ger- 

 many and Switzerland (II, 271), says that, according to Trapp, it appears every year, but in some years more 

 abundantly than i:i others. 



X This is not strictly true, as I thought when writing it. Boisduval, Rambur, and Graslin, in their work on the 

 caterpillars of Europe, state that Ccciioitympha Corinna feeds both on Triticum and Carex; and Wilde, accord- 

 ing to Kaltenbach (Pflanzenfeinde, 728), gives Lollum and Carex as the food of Pararge Achine. 



VOL. I. 46 



