GRAPTOLITES OF NEW YORK, PART 2 



297 



D i c r an o grap t u s divaricatus Walcott. Alb. Inst. Trans, v. 10. 1883. (Advance 



sheet. 1879. ]'- 34) 

 D i c el 1 o grap t u s divaricatus Lapworth. Roy. Soc. Can. Proc. & Trans, v. 5, 



sec. 4. 1886. p. 1S4 

 Dichograptus divaricatus ? Whitfield. Amer. Jour. Sci. Ser. 3. 1883. 26: 380 

 D i c e 1 1 o gr ap t u s moffatensis var. divaricatus Ami. Can. Geol. Sur. An. 



Rep't. v. 3, pt 2. 1889. p.6oK, 116K 

 D i c el 1 o gr ap t u s divaricatus Walcott. Geol. Soc. Am. Bui. 1890. 1:339 

 Di ce 11 o gr ap t u s divaricatus Gurley. Jour. Geol. 1896. 4:296 

 Dicranograptus (1.) icellograptus) divaricatus Roemer & Freeh. Lethaea 



Pal. 1897. 1 : 618 

 Dicellograptus cf. divaricatus T. S. Hall. Rec. Geol. Sur. N. S. Wales, v. 7, 



pt 2. 1902. p. 3 ; pi. 12, fig. 3 ; pi. 13, fig. 3* 

 Dicellograptus divaricatus Elles & Wood. Monogr. Brit. Grapt. pt 4. 1 904. 



p. 143 ; pi. 20, fig. 5a, 5b 



if 



213 



Fig. 212-14 Dicellograptus divaricatus (Hall). Fig. 212 Hall's original figures. Fig. 213 Enlargement 

 (x 5) of portion of branch of the original of the first of Hall's figures. Fig. 214 Enlargement (x 5) of sicular portion 

 of rhabdosome, showing sicula (pressed against branch) and small web. Original in National Museum 



Description. Branches of rhabdosome attaining' a length of 75 mm or 

 more each, varying between straight and rigid on one hand and curved and 

 flaccid on the other; the curvature being in some (see varieties) concave in 

 a short proximal part giving to this a V-like shape and abruptly changing 

 to a straight or slightly convex direction ; in the typical form widening rap- 

 idly from an initial width of .6 mm within 20 mm to one of i mm which is 



