460 



NEW YORK STATE MUSEUM 



I see in these the detached secondary branches of a Cyrtograptus, although 



there has not been found a complete rhabdosome which would give undis- 

 putable evidence of the generic position of the form. The absence of a 

 sicula at the narrow extremity of the bodies, however, demonstrates their 

 incomplete condition or their nature of broken-ofT branches of a larger rhab- 

 dosome, thereby refuting a possible reference to Monograptus, while the 

 peculiar sickle-shaped form, the equal size of the fossils and their geologic 

 horizon (late Niagaran), all point to a reference to Cyrtograptus as the 

 most satisfactory one. 



Fig. 441 Cyrtograptus murchisoni Carruthers. Copy from Perner to show form of 

 rhabdosome of Cyrtograptus. Fig. 442, 443 Cyrtograptus ulrichi sp. nov. Portions of 

 branches, enlarged x 5 



442 



443 



Description. Branches medium sized (30-40 mm), falciform, most 

 strongly curved at the proximal end, and becoming less curved and some- 

 times nearly straight toward the distal extremity; very narrow (.2 mm) at 

 the beginning, but gradually (within 20-25 mm) attaining their full width 

 (1.4 mm— 2 mm), which is then maintained. Thecae numbering 8 to 10 in 

 10 mm ; broad and relatively short (two and one half times as long as wide), 

 but possibly not preserved in full length, inclined at 20° overlapping two 

 thirds their length; without spines; not contracted towards the aperture 

 which is normal to the axis of the theca and straight ; ventral margin also 

 straight. 



Position and locality. Upper part of Bainbridge limestone (corre- 



