HENRY B. KUMMEL. FOOTNOTES [33] The author desires to express his obligation to Professor W. M. Davis for aid in the preparation of this article. It was first written under his direction and with the help of his suggestions when the author was in the graduate school of Harvard University. Prof. Davis is not responsible, however, for the statement of the views herein advanced, although in general it is believed that he is in accord with them. [34] Amer. Jour. Sci. 3d ser., vol. xxxvii, 1889, p. 423. Bull. Geol. Soc. Amer., vol. ii, p. 545. [35] The rough diagrams accompanying this paper may aid the reader who is unacquainted with the details of the region under discussion. The abbreviations on the above figure are as follows: C. The Connecticut. Cr. Pl. Crystalline plateau (the shaded area). F. The Farmington. H. Hartford. Ho. The Housatonic. Lm. Limestone area. M. Meriden. Mi. Mill River. Mt. Middletown. N. The Naugatuck. N. H. New Haven. No. The Norwalk. Q. The Quinnipiac. Qg. The Quinnebaug. S. The Scantic. Sa. The Saugatuck. T. Tariffville. Th. The Thames. The unshaded area is the Triassic sandstone lowland, and the blackened areas represent the ridges of the faulted trap sheets. [36] Am. Jour. of Sci., 3d ser., vol. xxxvii, p. 430. [37] Bulletin of Geol. Soc. of Amer., vol. ii, p. 554. [38] It is not desired to affirm that these periods of erosion and elevation began and ended promptly with the beginning or end of a period. The time statements must be considered as only approximate. [39] An exaggerated idea must not be had of the steepness and narrowness of these crystalline valleys. The valley of the Farmington, five miles up from where it opens into the Triassic sandstone, is 400 to 500 feet deep, and a mile and a half wide at the top. The Connecticut valley, just below Middletown, is about 400 feet deep and two miles wide at the top. These are fair representatives of the valleys in the crystalline rocks in the central part of the state. [40] Amer. Jour. of Sci., vol. x, 3d ser., 1875, p. 506. [41] McGee. Amer. Jour. Sci., 3d ser., vol. xxxv, p. 376. [42] Davis and Wood, Geographic Development of Northern New Jersey, pp. 413, 414. [43] “Rivers and Valleys of Pennsylvania,” Davis, W. M., published in The National Geographic Magazine, in 1889. [44] Davis, W. M., “Geographic Development of Northern New Jersey,” p. 397–8. [45] Davis, W. M., Amer. Jour. of Sci., 3d ser. vol. xxxvii., 1889, p. 432. [46] Geog. Devel. of Northern New Jersey, p. 404 et seq. Proc. Bos. Soc. Nat. Hist. Also Rivers of Northern New Jersey, p. 11 et seq. National Geographic Magazine, vol. ii, p. 93.