(iUAl'TOLI'J'ES OF NEW YORK. I'AUT 1 709 



P li J 1 1 o g r a p t u s t y p u s Brclgger. Die sil. Etageii 2 and 3. 1882. p. 41 



Ph y 11 ogr ap t us cf. typus Tnlll)erg. Skanes Grapt. in Sver. Geol. Und. Afli. 



och upps. ser. C, no. 60. 1882. p.21 

 Phy 11 ogr apt n s typus Malaise. Ann. dela Soc. Geo), de Belg. 1888. t.l."), bul. 



' p.42 

 Phy 11 og rap t us typus Ami. Geol. Sur. Can. Rep't. 1889. v..3, pt 2, p.50k ff 

 Phyllograp t u s typus Gurley. Jour. Geol. 1896. 4:294 

 Ph y 1 logr apt u s typus Roemer & Freeh. Lethaea palaeozoica. 1897. 1:605 

 Phyllograptus typus Elles. Quar. Jour. Geol. Soc. 1898. 54:494f 

 Phy Hog rapt us cf. typus Elles & Wood. Monogr. Brit. Grapt. pt 1. Pal. 



Soc. vol. for 1902. p.99, pi. 13, lig.5a,b 

 Phyllograptus typus Ruedemann. N. Y. State Paleoutol. Ann. Rep't. 1902. 



p.566 



This species, whicli, both b)' the gigantic size and the gi-eat variabilit\' 

 of its individuals, marks the acmic stage of development in the slioi't lived 

 genus Phyllograptus has been fully described Ijv its author and lately by 

 Elles and Wood. From these descriptions and the material in hand we 

 derive the following enumeration of the distinctive features of the 

 species. 



Description. The rhabdosome is exceedingly variable in relative length 

 and width, or in outline generally. Hall described it as being " elongate 

 ovate or lanceolate, broad oval or obovate," and Miss EUes's extensive measure- 

 ments demonstrate that in the Skiddaw s])ecimens, the variations extend from 

 long and narro^v forms, whose relative length and >\idth are .')7 and (i . 3 mm, 

 to short and broad forms with 25.4 and S.7 as corresponding figures. 

 Our material does not ([uite I'each these extremes, but still illustrates -well 

 the lack of fixation of the outline, and specially the fix'(|uent occurrence of 

 lanceolate forms and the tendency of the I'habdosome to attain its maximal 

 ^\■idtll in the sicular half. 



The thecae are in contact throughout their length, number i) to 10 in 

 10 mm, and are curved in all parts of the rhal)dosonie, viz in the sicular 

 portion slightly upward, which curvature lessens toward the middle poi-tion 

 and finally assumes an obliquely upAvard direction in the antisicular portion. 

 The apertures are but slightly mucronate. 



