GRAPTOLITES OK NEW YORK, I'ART 2 



2^1 



In America the genus has been first noted by Hall, who repeatedly 

 has figured typical Corynoicles as "germs"; thus in 'Palaeontology of New 

 York, volume 3, page 508, figure 7, where the form, here described as C. 

 calicularis, is readily recognized in the woodcut. It is explained as 

 "apparently the young of one of the singly serrated forms." Another very 

 correctly drawn example [1865, pi. B, fig. 19, see text fig. 125] which dis- 

 tinctly shows the basal part as described in this paper, is 

 designated as " a germ where the solid axis is on one side ; 

 the species probably belongs to the monoprionidian type." 

 C. calicularis has been recognized in the Normans- 

 kill shale of Canada and New York by Nicholson, Lap- 

 worth and Gurley. The occurrence of a species in the Utica F ,»£- z '* . Cor X", oi , dcs 



J i calicularis Nicholson. 



11 1 ill r ~1 Copies of Gurley's manu- 



shale was later announced by the present writer [iqooJ. script figures 



Comparing the figures of Corynoicles hitherto published with my 

 material, which comprises at least three different species, and an abundance 

 of excellently preserved specimens, I find that Whitfield's early figure of 

 the germ from the Normanskill shale had for its basis 

 evidently a more complete specimen than the English 

 authors had access to, for it shows not only a nema but also 

 the small transverse basal part, which I consider as the 

 sicula. It has been necessary to reproduce a considerable 

 number of specimens in enlarged drawings to bring out the 

 details of their structure and to illustrate their various 

 aspects [see text fig. 126 el seq. and pi. 13]. 



Fig. 125 Corynoides _,. f1 111 c r^ • i 1-1 



calicularis Nichoi- i he structure of the rhabdosome of Corynoicles which 



son. Copy of Halls fig- J 



or e g Remafns rm ' my material leads me to infer is that of a sicula bearing 



three thecae in the mature rhabdosome. The sicula does not seem to differ 

 in form or character from that of other graptolite genera. It is a rather 

 short, somewhat rapidly expanding cone, suspended from a nema, which 

 sometimes attains considerable length. Its aperture is plain, without 

 appendages or spines. The thecae originate close together by successive 

 budding and remain united throughout their entire crrowth. The oldest 



