712 Xi:\V YORK STATE MUSEUM 



Pli^ llograptus a ngus tif olius liruggcr. Die sil. Etagen 2 and 3. 1882. p.41 

 Phyllogr ap tus angu st i f ol i u s Ami. Geol. Sur. Can. Rep't. 1889. 



" V.3, pt 2, p.50k flf 

 Pliyllograptus angustifolius Holm. Geol. For. Forli. 1895. Band 17, 



heft 3, p.319, pl.3 

 PLyllograptus angustifolius Wiman. Geol. Inst. Upsala. Bui. 4. 1895. 



V.2, pt 2, p.39, pl.9, lig.8 

 Pliyllograptus angustifolius Elles. Quar. Jour. Geol. See. 1898. 54:496 

 Phy Hog rapt us angustifolius Elles & Wood. Monogr. Brit. Grapt. pt 1. 



Pal. Soc. vol. for 1902. p.lOO, pl.l3, iig.7a-f 

 Phyllograptus angustifolius Ruedemann. N. Y. State Paleontol. An. llep't. 



1902. p.554, 550, 570 



Specimens referable to this species are found in all three horizons of the 

 Deep kill section ; the form does not however attain its typical expression till 

 the third horizon (with D i p 1 o g r a p t u s d e n t a t u s ) , while the 

 specimens of the first horizon ("with Tetragraptus) approach P . i 1 i c i - 

 f o 1 i 11 8 and suggest a genetic connection between the two. The typical 

 material possesses the following distinguishing characters. 



Description. Rhabdosome consisting of four elongate, semielliptic 

 branches, which have nearly equal width throughout or are a little wider 

 near the sicular end. Thecae in contact throughout, numbering 11 to 13 

 in 10mm, being very little curved and directed at a uniform angle 

 obliquely upward, the inclination inci-easing somewhat toward the anti- 

 sicular end. The thecae of the sicular end are in their proximal 

 portion nearly horizontal and slightly bent down in their distal 

 portion. 



The apertures of this species are very characteristic, the mucronate 

 extension of the lower part of the same being much longer than that of 

 the iipper, so that the margin of the aperture appears to recede in an 

 upward direction. This extension attains a length of one and one half times 

 the width of the thecae. 



Position and localities. This species occurs in all three horizons of the 

 Deep kill section. It finds its typical development in the last horizon (with 



