GRAPTOLITES OF NEW VttRK, PART 2 269 



Pleurograptus linearis (Carruthers) 



Plate 15, figure i 



Cladograpsus linearis Carruthers. Roy. l'hys. Soc. Edinburgh. Trans. 1858. 



p. 467, fig. 1 

 Cladograpsus linearis Carruthers. Ann. & Mag. Nat. Hist. Ser. 3, v. 3. 1859. 



P- 2 4, fig. 3 

 Dendr ograp s u s linearis Carruthers. Geol. Mag. 1867. 4:70 

 PI eu r o gr ap s u s linearis Nicholson. Geol. Mag. 1867. 4: 257, pi. 15, fig. 1-5 

 Pleurograptus linearis Lapworth. Cat. West. Scott. Foss. 1876. p. 5, pi. 3, fig. 69 

 Coenograptus (Pleurograptus) linearis Roemer & Freeh. Lethaea pal. 



1897. 1:586, fig. 158 

 Pleurograptus linearis Clark. Geol. Mag. Ser. 4, v. 9. 1902. p. 498 

 Pleurograptus linearis Elles & Wood. Monogr. Brit. Grapt. pt 3 (in Pal. Soc. 



1903). p. 119; pi. 14, fig. 7; pi. 17, fig. 1 

 Pleurograptus linearis Oiin. Kongl. Fysiogr. Sallsk. Handl. N. F.. Bd 17. 1906 



But a single representative of this common zone fossil of the Hartfell 



shales of Scotland has, to my knowledge, been 



found thus far in the Utica shale. It comes from 



Fig. 186 Pleurograptus line- 



H11 1 -T) . /-\ ■ 1 -NT \T 1 • aris (Carruthers). Enlargement 



olland Patent, Oneida co., JN. \. and is now in ( x 4 > f portion of branch of the Hol- 

 land Patent specimen 



the New York State Museum. This has been 



described by Gurley in his manuscript as follows : 



Proximal end of rhabdosome not visible ; main stem somewhat S-curved, 

 giving off primary branches from the convex sides, at first at about a right 

 angle and subsequently at a constantly diminishing angle. Primary branches 

 curving gently distalward, giving off secondary branches at a much smaller 

 angle than that at their own origin. Primary branches near origin 0.4 mm 

 wide, distally 0.6 mm wide. The branches all increase slowly in width and 

 measure ad max. 0.7 mm. Thecae proximally on main stem, 20 in 25 mm. 

 Distally on branches, 25 in 25 mm. 



The bases of the branches are as far apart (15 mm) as in the van 

 simplex (Lapw. manuscript) Elles & Wood, but the branches are not 

 simple as in the latter. The thecae [see fig. 186] are long and slender; 

 seven to eight times as long as wide, overlapping one half their length and 

 inclined about 10". The free ventral margin is straight, the apertural part 

 introverted and opening within a shallow excavation. 



The associated forms of this fossil are unknown. 



