^O. 8.] BIBLlOGRArHY OF CONNECTICUT GEOLOGY. 35 



27. Hall, J. 



Paleontology of New York, volume 3, containing de- 

 scriptions and figures of the organic remains of the Lower 

 Helderberg group and the Oriskany sandstone, 1855-59 (with 

 volume of 120 plates), xii, 523 pp., 4°, Albany, 1859. 



The introduction to this volume (1-96) includes a general discussion 

 of the conditions of deposition and of mountain-making, with mention 

 . of formations occurring in Connecticut. 



28. Hawes, G. W. 



The trap rocks of the Connecticut valley. 

 Am. Jour. Sci., (3) ix, 185-192, 1875. 



Demonstration, by chemical analyses, of the common source of the 

 hydrous and anhydrous varieties of trap rock. 



29. Hawes, G. W. 



The rocks of the " chloritic formation " on the western 

 border of the New Haven region. 

 Am. Jour. Sci., (3) xi, 122-126, 1876. 



■Proof, by chemical analysis, of the similarity between the metamor- 

 phic schists and trap rocks of the New Haven region. 



30. Hawes, G. W. 



On the mineralogical composition of the normal Meso- 

 zoic diabase upon the Atlantic border. 

 U. S. Nat. jNIus., Proc, iv, 129-134, 1881. 



Chemical analyses of these rocks show that the unaltered Mesozoic 

 diabases are all very much alike, and are composed of augite, iron oxide, 

 in the form of magnetic and titanic iron, and a feldspar that has been 

 shown to be labradorite: the Triassic diabases are monotonously like 

 those in the older formations. (See Dana, 50.) 



31. Hitchcock, C. H. 



On the so-called talcose schist of Vermont. 



Am. Assoc. Adv. Sci., Proc, xiii, 321-329, i860. 



Description, both chemical and geological, of so-called talcose schist 

 of Vermont; name a misnomer; comparatively little magnesia. Brief 

 mention of the Connecticut schist as an e.xtension of the Vermont 

 area. 



32. Hitchcock, C. H. 



The relations of the geology of New Hampshire to that 

 of the adjacent territory. 



Geol. of New Hampshire, ii, 3-36, i pL, Concord, 1877. 



Reference to the formations of the Connecticut valley, including 

 the sandstone of Connecticut. 



33. Hitchcock, C. H. 



Maine, New Hampshire, Vermont, Massachusetts,. 

 Rhode Island, and Connecticut, geological formations. 



