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NEW YORK STATE MUSEUM 



the var. o r n a t u s of Dicellograptus complanatus which occurs 

 in the Upper Hartfell shales of S. Scotland. Of this variety it is stated in 

 the Monograph of British Graptolitcs, part 4, page 141, that "in some speci- 

 mens these two primary thecae appear to have been entirely modified to 

 stout spines which have a length of 4 mm-4.5 mm." In our specimen the 

 virgella seems to have been likewise developed abnormally (to a length of 

 5 mm) and the primary thecae also modified into large apertural winged 

 spines. The proximal halves of the three spines are connected by a web 



Fig. 179 Leptograptus flaccidus var. sp i n i f er mut. trifidus nov. The type specimen enlarged x 5 



and the entire center of the rhabdosome is thickened by peridermal layers 

 apparently to serve as a basis for the spines. 



Leptograptus annectans (Walcott) 



Plate 14, figure 5 



Graptolithus annectans Walcott. Utica Slate and Related Formations. Alb. 



Inst. Trans, v. 10. 1883. (Advance sheet. 1879. p.20, 35; pi. 1, fig. 2, 2a) 

 Graptolithus tenuis ? (Portlock) Ulrich. Cat. Foss. occur, in Cin. Gr. etc. 1SS0 

 Leptograptus annectans Ami. Can. Rec. Sci. [893. 9:1 So 

 Leptograptus annectans Lapworth. Roy. Soc. Can. Trans. 18S6. 4:183- 

 Leptograptus annectans Gurley. Jour. Geol, 1896. 4:296 



Description. Rhabdosome of medium size, branches attaining a length 



of 50 f- mm and showing gentle double curvature (first concave and then 



