HUDSON RIVER BEDS NEAR ALBANY 581 



Dimensions: Tergum: length along keel, 9.5 mm, width 6.7 mm; 

 length of another specimen (not complete) 13 mm, width 7 mm. 

 Scutum: length along keel, 12.5 mm, width 7.5 mm. Carina: 

 length of specimen (upper third missing) 12.3 mm_, width 10.2 

 mm; length of other large fragment, 16 mm, width 10 mm; width 

 of another fragment, 7 mm. Rostrum: length along keel, 8.3 mnij 

 width 4.7 mm. Upper latus : length 6.7 mm, width 8 mm. 



Lower Utica shale of Mechanicsville, Saratoga co. N. Y. Upper 

 Utica shale of Green Island, Albany co. N. Y. 



DESCRIPTION OF MAP 



The roman figures indicate the localities which furnished fos- 

 sils and correspond with the numbers of the stations described. 

 The boundary lines of the zones or belts have nowhere been ob- 

 served directly; they are only approximations obtained from the 

 location of the stations. The location of the fault, separating 

 the Cambric and Normans kill beds, is taken from Walcott's 

 map of the Taconic region (36). 



REFERENCES 



1 W. W. Mather. Annual report on the geological survey of the first 

 district. 1839 



3 W. B. & H. D. Bogers. Physical structure of the Appalachian 



chain. (Trans. Amer. ass'n geol. and nat. 1842. p. 474-531) 



8 Ebenezer Emmons. Geology of New York; rep't on the second dUh 



trict. 1842 



4 W. W. Mather. Geology of New York; rep't on the first district. 



1848 

 6 Lardner Vanuxem. Geology of New York; rep't on the third dis- 

 trict. 1842 



6 James Hall. Geology of New York; rep't on the fourth district. 



1843 



7 Paleontology of New York. 1847. t. 1 



8 1859. V. 3 



9 E. Billings. On the occurrence of graptolltes in the base of th« 



Lower Silurian. (Can. nat. and geol. 1861. 6:344-48) 



10 James Hall, (^ological report of Wisconsin. 1862. p. 47 (footnote) 



11 GraptoUtes of the Quebec group. (Can. org. remains. Decade 3. 



1865) 



12 H. A. Ificholson. On some fossils from the Lower Silurian rocki of 



the south of Scotland. (Geol. mag. 1867. 4:107-^13) 



