UUAPTOLITKS OF NEW YOUK. PAllT 1 731 



Climacograptus? antennarius Hall (sp.) 



Plate 16. flKures 21-28 



Climaeograptus antennarius Hall. Geol. Snr. Can. decade 2. 1865. p.ll2, 



pl.l3, fig.11-13 

 Diplograpsus antennarius Nicholson. Quar. Jour. Geol. Soc. 1868. 



24:139 

 Cryptograptus? antennarius Lapworth. Ann. and Mag. Nat. Hist, ser 5. 



1880. 5:174 

 Cryptograptus antennarius Gurley. Jour. Geol. 1896. 4:299 

 Cryptograptus? antennarius Elles. Quar. Jour. Geol. Soc. 1898. 



54:5 19ff, fig.31 

 Climaeograptus antennarius Roerner & Freeh. Lethaea palaeozoica. 1897. 



1:611 

 Cryptograptus antennarius Ruedemann. N. Y. State Paleontol. An. Rep't. 



1902. p.57l 



Description. Rhabdosome medium sized (about 20 mm), of nearly 

 uniform width (2.7 to 3.5 mm) ; provided with a stout sicular spine and 

 two long, slightly curved, rigid lateral spines, diverging at an angle of 

 100° to 110° and attaining a length of about 5 ram. Sicula not distinctly 

 observed. Thecae closely arranged (9 to 11 in 1 ram) ; parallel to the axis 

 of the rhabdosome ; apertures transverse oval incisions. Nemacaulus stout 

 and straight, its proximal extension relatively very long, measuring 18 mm 

 in one instance. 



Position and localities. Common in the horizon with D i p 1 o g r a p t u s 

 dentatus, exposed at the dam of the Deep kill. Hall's types came 

 from the Quebec group at Point Levis (upper horizon). Nicholson and 

 Elles have recognized this form among the Skiddaw gi-aptolites, and record 

 it as occurring at various places in the Upper Skiddaw slates ; Gurley lists 

 it also among the Arkansas graptolites. 



Remarhs. The synonymy shoAvs that this small form, which by its 

 outline and distal spines appears so well characterized, presents indeed, con- 

 siderable difficulties to a determination of its generic relations. While Hall 

 descri])e(l it as a Climaeograptus, it has subsequently been referred to 

 Diplograptus by Nicholson, to Cryptograptus bj- Lapworth, Gurley and 



