!2o The Ottawa Naturalist. August 



having their metropolis, or region best suited to their full and 

 regular development, much further northward. Examples of 

 such forms occur in little out-lying colonies, whose ancestors 

 found in their prehistoric wanderings a suitable habitat, or 

 survived in more and more restricted isolation as the surround- 

 ing country became unfitted through climatic changes for the 

 continuance of the species. 



Without waiting to consider sucli, all too-common, insects 

 as the cheerful House-fl}', the industrious Clothes-moth, the 

 " Jumpem-quick " and the " Walkem-slow," with numerous other 

 crawling and creeping domestic pets and pests which, like the 

 poor, are always with us, mention will be made of a few of the 

 more noticeable species which within more or less recent years 

 have come hither as permanent residents or as occasional 

 visitors. 



Commencing with the Lepidoptera there is, familiar to- 

 everyone, the common White Cabbage Butterfly, Pieris 

 RipcE Linn, the caterpillars of which de\our voraciously the 

 succulent cabbages and cauliflowers of the kitchen-garden, or 

 the fragrant mignonette of the flower plots. This butterfly came 

 to America b\- way of Quebec about the year 1859 and has since 

 that date become widely distributed across the continent. As- 

 the Europeans dispossessed the native Americans so this immi- 

 grant from across the Atlantic has become our most common 

 species and has almost supplanted our native white butterfly, 

 Pieris oleiacca Har, and the last Entomological News (\ol. x, 

 p. 46) records a similar displacement of the species as far west as. 

 Salt Lake Cit>-. 



An occasional visitor from across the line is Alctia argUlacect 

 Hub., the famous Cotton !\'oth of the Southern States, whose 

 numeious and industricjus progeny reduce by several million 

 dollars annually the product of the plant from which is obtained 

 such an important article of commerce, and one so necessar\- to 

 the comfort of mankind. The moth is of moderate size, expand 

 ing scarcely one and one-half inches, and is soberly coloured ;. 

 the front wings tawny or olivaceus with a few irregular trans- 



