cuAr'i'oi.rrKS of new youk. part i 711 



liemai-l'S. Aocoi'ding to Elles this species is characterized b}' (1) the 

 number df tliecae in a given nnit of length, (2) the foi-m of the aperture, 

 which is e(piall\ extended at its u])per and lower limits. These characters 

 serve speciall}' to distinguish the narrow variation of P . t y p u s from 

 P . a n g n s t i f o 1 i u s , -which has more closely arranged thecae, and longer 

 apertural niucros, \\'liich are extensions only of the lower part of the 

 apertures giving the latter an oblique direction. x\.lso, the character of the 

 curvature of the thecae and, specially, the direction of those of the 

 antisicular })ortion furnish a means of distinction of P . t y p u s from 

 P . a n <>• u s t i f o 1 i u s . 



P. ilicifolius exhibits, in the Deep kill section, a variability of 

 foi'in similar to that of P. typus. It also possesses a similar character 

 of curvature of the thecae, but has cori-esponding to its generally smaller 

 size, more closely arranged thecae, and, besides, longer and diflPerentl}' 

 shaped apertural mticros. P. typus and ilicifolius, though not 

 mentioned by Hall as occurring in different associations are in their principal 

 development, separated in the Deep kill section, where P. ilicifolius 

 precedes P . typus. 



Phyllograptus angustifolius Hall 



Plate 15, liguies 31-34 



P h y 1 1 o gr a p tu s angustifolius Hall. Geo). Sur. Can. Rep't. foi'1857. 1858. 



p.l39 

 P li y 1 1 o g r a p t u s angustifolius Salter. Quar. Jour. Geol. See. 1863. 19:137, 



fig. 7a, h 

 Pliy 11 ogr a pt u s angustifolius Hall. Geol. Sur. Can. decade 2. 1865. p.l25, 



pl.l6, fig.17-21 

 P h y 1 1 g r a p t u s angustifolius Nicholson. Quar. Jour. Geol. Soc. 1868. 



24:132 

 Pbyllograptus angustifolius Linnarsson. Sver. Geol. Und. 1879. Afh. 



och upps. ser.C, no. 31. p. 5 

 Phy llogr a p t u s cf. angustifolius Tullberg. Sver. Geol. Und. 1882. Afh. 



och upps ser.C, no.50. p. 22 



