482 



NEW YORK STATE MUSEUM 



Lasiograptus bimucronatus Tullberg. Sver. Geol. Und. Ser. C, no. 50. 



1882. p. 20 

 Lasiograptus mucronatus Lapworth. Roy. Soc. Can. Proc. & Trans. 



1887. 4:178 f 

 Lasiograptus bimucronatus Gurley. Jour. Geol. 1896. 4:299 

 Hallograptus (Lasiograptus) bimucronatus Roemer & Freeh. 

 Lett). Pal. 1897. 1:672, fig. 224 



Lasiograptus bimucrona- 

 tus Roemer & Freeh. Lethaea 

 Pal. 1897. 1:672, fig. 224 

 Diplograptus bimucrona- 

 tus Clark. Geol. Mag. Ser. 4. 

 1902. 9:499 



Besides the slender form 

 with loosely arranged thecae just 

 described, there occurs in some 

 outcrops of the Normanskill 

 shale, notably those at Glenmont 

 and Mt Moreno, still another 

 coarser form, which differs in 

 greater final width of rhabdo- 

 some, closer arrangement of 

 thecae and the mucros, which on 

 account of their earlier divergence 

 appear nearly always paired in 

 the shale material. The peri- 

 derm is thicker, and the mucros 

 are stronger, frequently straight 

 and of the appearance of the hori- 

 Loison.) zontal spines of Glossograp- 

 q u a d r i m u c r n a t u s . 



Fig. 458-63 Lasiograptus bimucronatus (Nicholson. 

 rig. 458-61 Copies of Hall's figures (originally referred to G rap 



tolithus whitfieldi). Fig. 462 Portion of specimen showing | ,, g 



the appendages in a much macerated (the usual idition. Fig. 



46-1 Young rnabdosoine showing at the upper end the fixation "I T 



the ledges to-the nemacaulus. The last two figures, x 5 It agrees 111 its Cliai'aCtei'S aiUl 



dimensions with Nicholson's original description which is the only one 

 extant. 



