GRAPTOLITES OP NEW YORK, PART 2 407 



Climacograptus typicalis Hall 



Plate 2S, figures 6, 7 



Climacograptus typicalis Hall. Can. Org. Rem. Dec. 2. 1865. p. 27, 



28, 57; pi. A, fig. 1-9 

 Climacograptus typicalis Hall. N. Y. State Cab. Nat. Hist. 20th An. 



Rep't. 1868. pi. 2, fig. 1-9 

 Climacograptus typicalis Hall. N. Y. State Cab. Nat. Hist. 20th An. 



Rep't. Rev. ed. 1868. pi. 2, fig. 1-9 

 Climacograptus typicalis Walcott. Alb. Inst. Trans. v. 10. 1883. 



(Advance sheets, 1879. p. 34) 

 Climacograptus typicalis Ulrich. Am. Geol. 1888. 1 1183 

 Climacograptus typicalis Walcott. Geol. Soc. Am. Bui. 1890. 1 1339 

 Climacograptus typicalis Winchell & Schuchert. Geol. Minn. 1895. v - 



3, pt 1, p. 82, fig. 4 

 Climacograptus typicalis Gurley. Jour. Geol. 1896. 4:298 

 Climacograptus typicalis Roemer & Freeh. Lethaea Pal. 1897. 1 :6i2 

 Climacograptus typicalis Ruedemann. N. Y. State Mus. Bui. 42. 1901. 



P-5 2 3 « 

 Climacograptus typicalis Nickles. Cin. Soc. Nat. Hist. Jour. 1902. 20:68 



Description. Synrhabdosome not observed. Rhabdosome long (66 

 mm+), narrow, with extremely narrow whip-shaped sicular end (.3-4 mm) 

 which in the space of about 16 mm attains the mature width (2-2.4 mm). 

 The latter is maintained to the growing end. Lateral sides convex, smooth, 

 broad. Sutural grooves so faint that they are observed only in exceptional 

 cases. Sicula short (1.2 mm), its aperture possessing two short mucros. 

 Thecae closely arranged (11-15 in 10 mm), overlapping one third in mature 

 part, one fourth and less at sicular end ; twice bent ; in the proximal half 

 parallel to axis of rhabdosome, then abruptly turning outward at nearly right 

 angle and finally again becoming parallel to axis. Aperture horizontal to 

 slightly everted (especially in neastic part) apertural excavation short (one 

 fourth of ventral margin) and deep (one fourth of width of rhabdosome). 

 Nemacaulus very thin and short and hence rarely observed. 



Position and localities. Hall cites this species from the " Hudson 

 river" ; Walcott from the Utica and " Hudson" shales ; Winchell and Schu- 



