3 86 



NEW YORK STATE MUSEUM 



Diplograptus pristis (Ruedemann) Tornquist. Zool. Centralbl. 1897. 4:4 

 Diplograptus aff. whitfieldi Roemer & Freeh. Lethaea Pal, 1897. v. 1, 



pi. A, fig. ib, ic 

 Diplograptus foliaceus Ruedemann. Am. Xat. 1898. 32:6 

 Diplograptus quad rim ucronatus et foliaceus Ruedemann. X. Y. State 



Mus. Bui. 42. 1901. p. 528 

 Diplograptus foliaceus Ruedemann. N. Y. State Mus. Mem. 7. 1904. p. 528, 



ng- 9 

 Orthograptus quadrimucronatus Ami. Geol. Sur. Can. Sum. Rep't for 



1904. (1905) p. 12 

 Diplograptus (Orthograptus) quadrimucronatus T. S. Hall. Geol. 

 Sur. Victoria Rec. 1906. v. 1, pt 4, p. 275; pi. 34, fig. 10, 11 

 Description. Entire colony forming a synrhabdosome which is com- 

 posed of 30 or more sicula-bearing rhabdosomes. The latter stout and long, 

 quadrilateral, the lateral and frontal sides of approximately equal width ; 

 the lateral faces plain, the frontal ones straight or very 

 gradually increasing in width to 3 mm (indicating a width 

 of 1.5 mm for one side, exclusive of the apertural spines); 

 attaining a length of 60 mm and more in the largest 

 fragments. Periderm consisting of a thick outer layer 

 and a fibrous inner one [see " Remarks "]. Sicula stout, 

 nearly 2 mm long, provided with a straight apertural 

 margin and a distinct virgella. Thecae relatively broad 



Fig. 336 Glossograp- 



(Haii?. u cop r y^fone r of n Hai l i's and short, three times as long as wide, overlapping two 



original figures. Sreatso text i i i • i i r 1 r '11 



fiK'"-e 9 thirds their length ; forming an angle of 3CV-32" with the 



axis, numbering 11 in the space of 10 mm at the sicular end and 10 at the 

 antisicular end in the typical form. Each apertural angle produced into a 

 mucronate spine which equals in length the width of the aperture and is 

 rectangular on the axis of the theca. Nemacanlns thin and apparently 

 little flexible, hence mostly missing ; in some cases broad and expanded 

 into a " vesicle." 



Position and localities. Mall originally described Grapt. quadri- 

 mucronatus from the Utica shale at Lake St John, in the Province of 

 Quebec, where it occurs in association with Leptogr, flaccid us 



