C.RAPTOLITES OF NEW YORK, PART 2 



0/ . 



pressed state from the adjoining strata | nos. 1 1 and i 3 | of the same locality ; 

 and still others from the same horizon in Granger, Minn, and from the 

 Triplecia bed [no. 10 1 near Wyckoff, Minn. All of these were kindly 

 furnished by Professor Sardeson. 



All these specimens agree without the least variation. From them 

 the following data, supplementary to Hall's description can be gathered : 



The rhabdosomes are throughout of small size (the greatest length 



observed in an incomplete specimen being only 



20.5 mm and the majority not attaining more 



than 14 mm), and small width (Hall's type 



2.6 mm, the majority not over 2 mm) this width 



being attained very gradually, while the sicular 



end is already 1.4 mm wide, so that the rhabdo- 



some gives the impression of being of uniform 



width. The section of the rhabdosome is, as 



described by Hall, broad oval and both lateral 



sides are convex. The sicular extremity is 



rounded, furnished with a minute virg-ella and 



two short lateral spines. Siculae extremely 



common in seme of the beds, small (1.6 mm), 



slender, with straight transverse aperture, a 



short rodlike virgella and small opposite lappet 



or mucro. Thecae numbering: 11 to 1 3 in 10 mm 



& o -rj . 5 - ZKi , x 323 



(28-32 to the inch), 1 inclined at an angle of 30 Fig. 3 i 9 ?2 Di P iogra P tus P eost a 



(Hall). Fig. 31Q Hall's tvpe specimen, 



to 40 , imbricated on the median line; overlap- *£^J^£*£j£e*l&$^ 



...... . , . . Granger, Minn. Fig. 320 Original of 



ping- two thirds their length ; lour times as long Hair's figure of Gr. pristis [ P i. 72 , 



10 o > o fig if, ig]. The original of this fig- 



•1 f t_ 1 »_* 'i-1 J J ure is from the Lorraine shale at Lor- 



as wide ; ot subrectangular section ; with rounded raine. n.y. Fi g . 3 2 3 sicuia, from Granger, 



Minn. X 5 



sides. Aperture normal on axis of theca. 



Position and localities. This is the common Diplograptus of the " Dip- 



1 Hall gives 26 in the space of an inch, which is a little less than our specimens show, 

 the New York type included, which has nearly 30 in the space of an inch. Hall's smaller 

 figure is undoubtedly due to the inability of obtaining camera drawings at the time. 



