712 NEW YORK STATE MUSEUM 



Pli} llograp tus an gii8 tif ol ius Jiruggcr. Die sil. Etagen 2 and 3. 1882. p.41 

 Phyllograptus angiistifolius Ami. Geol. Sur. Can. Rep't. 1889. 



V.3, pt2, p.SOkff 

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



heft 3, p.319, pl.3 

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



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

 Phyllograptus angustifolius EUes, Quar. Jour. Geol. Soc. 1898. 54:^196 

 Phyllograptus angustifolius Elles & Wood. Monogr. Brit. Grapt. pt 1. 



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

 Phyllograptus angustifolius Ruedemann. N. Y. State Paleontol. An. liep'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 lio^vever 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 hoiizon (Avith Tetragraptus) approach P . i li c i - 

 folins 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 Avidth throughout or are a little ^vider 

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

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

 obliquely uj)ward, the inclination increasing 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 upper, 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 



