Mountain of Montreal. 97 



In a former number some account was given of tlie iclineumon 

 flies, and of their mode of providing for their young, by deposit- 

 ing their eggs in the bodies of the larvge of the wheat midge. All 

 caterpillars are more or less subject to the same scourges. In the 

 valuable little work published, Dr. Fitch, " On the noxious, bene- 

 ficial and other insects, of the State of New York," the following 

 interesting paragraph occurs. 



" The knowledge and skill which these ichneumon and other par- 

 asitic hymenopters often shew in their proceedings are truly wonder- 

 ful. Every person will recollect the larva of the Isabella tiger-moth, 

 (^Arctia Isabella,) the large caterpillar with stiff even-shorn hairs 

 of a tan color, and black at each end of his body, which crawls 

 about our yards, and often enters our dwellings, and will probably 

 have observed the fact that if, when crawling, he is rudely touched 

 he suddenly stops and doubles himself together for a moment, and 

 then straightens himself again and resumes his journey. The long 

 stiff hairs with which he is protected, much like a porcupine, we 

 should think would render it impossible for an insect enemy to 

 place an Qgg anywhere upon his skin. Mr. P. Reid tells me he 

 once saw one of these caterpillars crawling with a hurried eager 

 step across a dusty road, with an ichneumon fly pursuing him, 

 striving to cling upon his back, but falling off in consequence of 

 the rapid motion of the caterpillar. The fly finding itself frus- 

 trated in its every effort,. next, as if humming to itself the refrain, 

 ' It will never do to give it up so,' flew a few feet forward of the 

 caterpillar, and turning, darted back with all its energy, hitting the 

 caterpillar square in his face. The caterpillar thus roughly as- 

 sailed suddenly stopped, and bent himself together in his accus- 

 tomed manner, and in an instant the fly alighting upon his back, 

 appeared to fix an Qgg at the margin of one of the breathing 

 pores, which had become fairly exposed by the caterpillar doubling 

 his body thus together. In a moment the caterpillar was reco- 

 vered from his shock, and was crawling rapidly forward again, 

 when the fly struck him a second time in the same way, and thus 

 he was stopped, and had an egg deposited in his side three times 

 before he reached the tall grass beside the highway, in which he 

 was secure from further molestation." 



4. Terrestrial Mollusca. — While turning over the stones in 

 search of geological specimens, I found during a single visit to 

 the mountain no less than five species of land shells. Three of 

 these were easly determined — a fourth appears to be a described 



B 



