Lost or Mutilated Lhnbs of Insects — Oestlund. 143^ 



14. No red sandstones or shales were reported by Mr. Swan. 



15. Below the sandstones of formation 13, granite was reached. 

 Possibly this was quartzite (see Lake City well, formation 14), and so, forma- 

 tion 14 instead of 15. Unfortunately no borings are at hand. 



The well was bored to increase the water supply at the grist mill. 

 Flow, 1,000 gallons per minute of soft water. Total depth, 590 feet. 



XII. The Mankato Well*— C. W. Hall. 



Formation 1. Ordinary bowlder clay or till 290 feet. 

 2, 3, 4, 5, 6, 7 and 8. Wanting. 



9. This formation is present beneath quarries and in all the surround- 

 ing bluffs. It is quite possible that a part of the material referred to for- 

 mation 1 belongs here. 



10. The borings at 380 feet show a dolomitic rock, possibly somewhat 

 shaly. At 390 feet a green shale and sandstone comes in. Estimated thick- 

 ness of this formation 160 feet. 



11. The drillings from 450 feet to 850 feet show a clear white sand 

 having at the top a slightly pinkish tint. Thickness of these white sands 

 400 feet and more. 



12. At 915 feet a red shaly sandstone appears which may be the 

 representative of this formation in the south west."|" 



13. From 1,010 to 1,240 feet the drillings are entirely sands and rather 

 coarse in texture. The color at 1,010 feet is pink, at 1,240 feet nearl}^ white. 

 Thickness not less than 230 feet. 



14. At 1,265 feet a pink color comes in which at 1,340 becomes red. 

 The red color with an occasional fading into pink continues to the bottom 

 of the well. The drillings saved from 1,875 feet down to the bottom, seemed 

 to show a fine red shale at every point. Total depth 2,204 feet. The well is 

 not at present used for water supply. 



[Paper T.] 



On the REPRODUCTION" OF LOST OR MUTILATED LIMBS OF 



INSECTS. — 0. W. Oestlund. 



The reproduction of a lost limb is a fact well known to take 

 place among the lower arthropods, especially the crustaceans and 

 spiders. Such a lost limb is not produced by a gradual growing 

 out, as might be supposed, like the growth of a limb or twig of 

 plants, but the growth is internal and the limb does not appear 



•See further details by Warren Upham in Geol. and Nat. Hist. Sur. Minn. Final 

 report vol. 1. j>p. 422 et seq. 



fAuwther view is that this rock may represent the top ot fhe Potsdam, and that 

 here, > ear ihe majgln o) the Hniiit ( roix aen, no shales corresponding to formation 12 of 

 the Mississippi river valley viere formed In that case No. 11 above w< u li stand tor the 

 eutire thi kiiess of the Saint Croix, or formations I 1, 12 and 13. There is no sufficient 

 geologic reason why the Potsdam may not contain white and gray sandstones as well as 

 pink and red. 



