GRAPTOLITES OF NEW YORK, PART 2 



243 



Protovirgularia dichotoma (McCoy) ? Gurley 



Plate 10, figure 9; plate 11, figures 8, 9 



Protovirgularia dichotoma McCoy. Ann. & Mag. Nat. Hist. 1850. 6:272,273 

 Protovirgularia dichotoma McCoy. Brit. Ass'n 20th Rep't. Notices and 



Abstract. 185 r. p. 107 

 Protovirgularia dichotoma McCoy. In Brit. Pal. Foss. (Sedgwick Brit. Pal. 



Rocks). 1853. p. 10; pi. 1 B, fig. 11, 11a, 12, 12a 

 Protovirgularia d i c h o t o m a Malaise. Acad. Roy. Belg. Bui. 1890. 20: 447 



The collection of graptolites from the Normanskill shale at Stockport, 

 Columbia co., N. Y. in the National Museum, contains two curious small 

 fossils which are obviously graptolites but differ in structure from all 

 associated forms. They have been identified by Dr Gurley 

 with Protovirgularia dichotoma and the follow- 

 ing description is given in his manuscript : 



Of this species, which appears not to have been 

 observed since McCoy's time, I have two specimens, one 



not very well preserved, showing two branches of the poly 

 pary and the other a short fragment of a branch in a fair 

 degree of preservation. Neither of these show any details, 

 such as McCoy describes and figures. All that can be 

 said from them is that the branches are about 1.5 mm 

 wide and the transverse spiculate processes about 32 in 

 25 mm. The last feature contrasts with McCoy's descrip- J&^ ciney/pen* ac- 

 tion, which gives the number as 24 in 25 mm. Besides Ipf c °mens ma'al un a C er P Dr 

 these definite points of structure, both specimens are sur- Gurle > , ' s supervision. x 2 

 rounded in the rock by some indefinite lines and a general filmy appear- 

 ance somewhat resembling that occurring in the scopulate specimens of 

 Diplograptus pristis (?). I suspect that the present species possesses 

 more structure than is now known and that perhaps the polypary described 

 by McCoy may prove only the framework (of a more resistant substance) 

 than the rest of the individual. 



Horizon and locality. Two specimens from the Lower Dicellograpsus 

 zone, Stockport, N. Y. 



The text figure 149 was made under the supervision of Dr Gurley. 

 We add two camera enlargements which were obtained with the aid of a 

 strong illuminating lens when the specimens were immersed. From these 

 latter figures one gets the impression that the transverse spiculate processes 



