202 SYSTEMATIC PALEONTOLOGY 



Not uncommon in the Trenton rocks of New York, Kentucky, and 

 Tennessee. Similar forms occur in the Black River and Stones River 

 formations of the United States and Canada. 



Collections. Maryland Geological Survey, IT. S. National Museum. 



TETRADIIJM CELLULOSUM (Hall) 

 Plate XLII, Figs. 3-5 



Phytopsis cellulosum Hall, 1847, Pal. New York, vol. i, pp. 39, 315, pi. ix, 

 figs. la-d. 



Description. The principal features of this index fossil of the Low- 

 ville limestone are well shown in Hall's original illustrations reproduced 

 in the present volume. As is well known, the main specific character of the 

 fossil is the occurrence of the corallites in small bunches which, in the 

 course of growth, form elongated, subcylindrical or compressed stems. 

 These stems sometimes anastomose, forming a network. In transverse 

 sections the generic character of the coral, the quadrangular corallites 

 with four regularly placed septa, is well brought out. This most char- 

 acteristic coral of the Lowville limestone has a wide distribution in New 

 York and Canada and the Appalachian and Ohio valleys. 



Occurrence. CHAMBERSBURG LIMESTONE (Tetradium cellulosum 

 bed). Fort Loudon and the railroad cut two miles southwest of Marion,. 

 Franklin County, Pennsylvania. 



Collections. Maryland Geological Survey, IT. S. National Museum. 



CLASS GRAPTOLITOIDEA 



Order GRAPTOLOIDEA 



Family DIPLOGRAPT1DAE 



Genus GLIMACOGRAt TUS Hall 

 CLIMACOGRAPTUS PUTILLUS (Hall) 



Plate LII, Figs. 5-7 



Oraptolithus putillus Hall, 1865, Geol. Surv. Canada, Org. Rem., dec. 2, 



pp. 27, 44, pi. A, figs. 10-12a. 

 Climacograptus putillus Ruedemann, 1908, Mem. New York State Mus., 



vol. xi, pt. 2, pp. 415-419, pi. xxviii, figs. 14, 15, text figs. 368-374, 376, 



377. 



