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30, and we have had some tolerable falls of snow, 

 with continued frost, for some days. My first excur- 

 sion was to Killingbeck, about three miles from Leeds, 

 where we discovered a very extensive colony of yellow 

 ants (Formica flavd) in a hilly part of the lawn sur- 

 rounding the house of Thomas Walker, Esq., which 

 appeared to penetrate full two feet below the surface. 

 Upon breaking up the ground with a spade, the earth 

 came up in solid masses and partially frozen, each of 

 which presented numerous apartments and galleries, 

 in many places quite blocked up with ants, very close 

 together, probably to collect a little warmth. When 

 first exposed to the air, they moved their antennae 

 slightly, and walked in a very feeble manner, endeavour- 

 ing to get under shelter : many which fell upon the 

 snow became very quickly motionless and perished : 

 amongst them were several larvae, in different stages of 

 growth, from half a line to two lines in length. Al- 

 though I did not dig to the bottom of the nest, I 

 brought home, I should think, at least 1500 or 2000, 

 numbers of which have since died from some cause or 

 other; perhaps the sudden change of temperature. 

 My second excursion was to Kirkstall woods, when 

 the thermometer was scarcely 30 F. I dug at my 

 old hill of formica rufa (the hill or horse ant), but 

 could not find a single specimen, so that they must be 

 at a very considerable depth : however, I was fortunate 

 enough to find a nest of the turf ant (Formica 

 ccespitum), which was beneath a patch of weeds, with 

 a slight layer of earth, upon one of the many large 

 blocks of stone lying about the woods. The outside 

 of this habitation was cased with ice ; and, when the 

 thin covering they had, and the cold stone for a found- 

 ation, is considered, these must have been at a much 

 lower temperature than the yellow ants. The colony 



