32 The Field Naturalist' s Quarterly Feb, 



to their chorographical ancestral history. The snail fauna 

 of England is made up of many different groups, some of 

 which are characteristic of, and reach their highest develop- 

 ment in, warm climates ; while others are a part of more 

 northerly fauna. Representatives of the former clan might 

 be expected to exhibit a prolonged period of hibernation in a 

 climate such as ours. This is actually the case. Cryptom- 

 phalus, with its brightly variegated browns and yellows, and 

 the darkly-striped red and yellow shells of Tachea, may be 

 taken as characteristic examples of the southern forms, and 

 it is in these species that we find hibernation most marked 

 and most prolonged. This is especially seen in C. aspersus, 

 which seems to retire for the winter rather according to the 

 time of the year than the temperature of the particular 

 autumn. The middle of a warm wet September will some- 

 times find this species in winter quarters, from which perhaps 

 it will not emerge until the following March or April. I 

 once tried to thoroughly wake up some specimens in mid- 

 winter, but no allurements in the way of warmth, wetness, 

 or food, had any effect. Tachea behaves in much the same 

 way, though its period of rest is, as a rule, somewhat shorter, 

 and it is more liable to be tempted out by warm rain in mid- 

 winter. In marked contrast with such species as the fore- 

 going is such a one as Vitrina pellucida, with its fragile pale- 

 green shell. One finds that Vitrina is not only willing to 

 walk about in cold weather, but actually seems to prefer to do 

 so. I have seen the dead leaves of the woods and hedge- 

 banks swarming with this almost shell-less mollusc while 

 skating was being indulged in, and it was freezing hard. 

 Vitrina is an essentially boreal species, and shows its con- 

 tempt for our English attempts at frost, while the long and 

 marked aestivation in which it indulges is presumably indica- 

 tive of disgust at our tropical summer. For such southern 

 forms as Tachea our summer is not hot enough, and they do 

 not, as a rule, aestivate in this country, or at any rate not to 

 anything like the same degree as is their custom in, e.g.. 

 Southern France. Cyclostoma elegans is our representative 

 species of a great tropical group, and it hibernates in a marked 

 way. Curiously enough, it also preserves in this country the 

 habit of sestivating, and in the height of summer is often to be 



