278 NEW YORK STATE MUSEUM 



Coenograp tus gracilis Lapworth. Cat. West. Scott. Foss. 1876. p.5; pi. 3, fig. 65 

 Coenograptus gracilis Lapworth. Belfast Nat. Field Club. F.ep't & Proc. Apx. 



1877. p.142; pi. 7, fig. 11 

 Gr.aptolithus gracilis Walcott. Alb. Inst. Trans, v. 10. 1883. (Advance sheet. 



1879- P-35) 

 Coenograptus gracilis Tullberg. Sver. Geol. Unders. Ser. C, no. 50. 1882. p.20 

 Mon o gr apt u s graci 1 i s Whitfield. Am. Jour. Sci. Ser. 3. 1883. 26:380 

 Coenograptus gracilis Herrmann. Nyt Mag. f. Naturvidensk. 1885. 27:359; 



pi. 2, fig. 21 

 Coenograptus gracilis Lapworth. Roy. Soc. Can. Proc. <S; Trans. 1887. 4: ij8f 

 H eli co grap t u s graci 1 i s Dodge. Am. Jour. Sci. Ser. 3. 1890. 40:153 

 Stephanograptus gracilis Walcott. Geol. Soc. Am. Bui. 1890. 1:338 

 Coenograptus gracilis Gurley. Geol. Sur. Ark. An. Rep't. 1892. 3:408 

 Stephanograptus gracilis Gurley. Jour. Geol. 1896. 4:296 

 Coenograptus gracilis Roemer & Freeh. Lethaea Pal. 1897. 1: 584, 585, fig. 155 

 Coenograptus gracilis T. S. Hall. Geol. Mag. n. s. Dec. 4, 1899. 6:445 

 Coenograptus gracilis Ruedemann. N. Y. State Mus. Bui. 42. 1901. p. 528 

 Coenograptus gracilis Ruedemann. N. Y. State Mus. Bui. 52. 1902. p. 583, fig. 13 

 Coenograptus gracilis Fearnsides. Section C, Belfast. 1902. p.i 

 Coenograptus gracilis Clark. Geol. Mag. Ser. 4, v. 9. 1902. 13.498 

 C o e n o g r ap t u r. g r a c i 1 i s Weller. Geol. Sur. N. J. Pal. 1902. 3:53 

 Nemagraptus gracilis Elles & Wood. Monogr. Brit. Grapt. pt 3. 1903. p. 127; 

 pi. 19, fig. ia-f 



Description. Rhabdosome consisting of two narrow (.2-6 mm) prin- 

 cipal branches which are bent in a sigmoid curve, and attain a length of 

 60+ mm; and of numerous (as many as 18 on cither side) secondary 

 branches, which are arranged in regular series on opposite sides of the 

 main branches near the center of the colon)' , are gently curved, in their 

 gfeneral direction conforming to the curvature of the main branches, fre- 

 quently quite flaccid and attaining great length ( 1 10 mm and more). They 

 begin at a distance of 1 mm from the sicula, and are, in the typical speci- 

 mens from 1.4-2 mm apart; each arising opposite the aperture of a theca. 

 They increase in width from .4 mm (in lateral aspect) to .8 mm. The sicula 

 is small (1 mm), though conspicuous owing to its position in the center o( the 

 rhabdosome ; but most frequently placed vertically in the shale and hence 



