182 DR. C. CHILTON ON THE SUBTEREANEAN 



1. East Eyreton, about 15 miles north of Cliristcliurcb, altitude about 120 feet above 

 sea-level *. 



2. Lincoln, about 12 miles south of Christcburch, altitude about 28 feet above sea- 

 level. 



3. Leeston, about 27 miles south of Christcburch, altitude about 60 feet above sea- 

 level. 



4. Ashburton, about 50 miles south-west of Christcburch, altitude about 323 feet 

 above sea-level. 



5. Winchester, about 85 miles south-west of Christcburch, altitude about 136 feet 

 above sea-level. 



I have also heard of Crustacea being seen from wells at several other localities in 

 addition to those given above ; but leaving these out of consideration, the localities given, 

 from all of which I have actual specimens, are sufficient to show that these Crustacea 

 are widely distributed in Canterbury, so far as distance north and south is concerned ; the 

 distribution from east to west, so far as at present known, appears to be much more 

 restricted, and it is perhaps worthy of notice that all the places mentioned are within 

 short distances of the sea, none of them being more than 10 or 12 miles from it. 



No doubt further research will demonstrate the occurrence of these Crustacea at many 

 other places ; at the same time it is to be remarked that they do not occur in the 

 artesian waters of Christcburch. Tlie area in which artesian wells can be sunk with 

 success is a narrow belt parallel to the sea, extending from Flaxton, north of the Waima- 

 kariri, to Lake Ellesmere, the inland boundary being the contour of about 50 feet above 

 the sea. The depth below the surface of the first water-bearing stratum varies from 

 about 55 feet at Riccarton to 136 at New Brighton, on the sea-coast, and there is a 

 second water-bearing stratum at about double the depth of the first in each locality. 

 Crustacea appear to be absent from botli of these water-bearing strata ; I have 

 frequently sought for them in vain in water from wells to the first stratum, and others 

 have been equally unsuccessful ; moreover, as the water of these wells is used throughout 

 the whole district for drinking-purposes without previous filtering, the animals would 

 certainly have been noticed had they been present. With regard to the wells reaching 

 to the second stratum, Mr. R. M. Laiug tells me that he endeavoured to collect Crus- 

 tacea from a well of this kind at the Christcburch Boys' High School, Bath, by fixing a 

 muslin bag over the mouth of the pipe for some hours, but that no trace of any 

 Crustacea was obtained. Of course, this evidence, though very satisfactory so far as it 

 goes, is by no means conclusive, and it would be well to repeat the experiment in other 

 wells and at different times, in order to confirm or disprove the results of the single trial 

 already made. 



In the above-mentioned ' Handbook of Christcburch ' [63, p. 33] it is pointed out that 

 althouo-h it is commonly thought that the main source of the water-supply of the artesian 

 wells is the leakage of the bed of the Waimakariri, the few careful observations that have 



* This height has heen obtained from the Survey Department through the kindness of Mr. C. W. Adams, Chief 

 Surveyor, Dunedin. The other heights are taken from the figures given iu the time-tables published by the New- 

 Zealand Railway Commissioners. 



