CLAss n HYDROZOA— GRAPTOLITOIDEA 131 



outline and rounded extremities, ornamented with two rows of isolated spurs ; 



Fig. 205. 



a, c, Cliiruicograptus typicalis Hall. Ordovician (Tren- 

 ton limestone) ; Cincinnati, Ohio ; a, Vertical section, 

 showing common axis in the centro, enlarged ; 5, Poly- 

 paiy of the natural size ; c, Cross-section, enlarged. 

 d, e, Di'plo(}raptus jmlmeus Barr. Silurian ; Prague ; d, 

 Polypary of the natural size ; e, Polypary enlarged. 

 /, Diplograftus foliaceus Murch. Silurian (Llandeilo 

 Group) ; Scotland. Natural size. 



Fio. 206. 



Diplograptus foliaceus Hall.iUtica shale (Ordovician); 

 Dolgeville, New York. Synrhabdosome showing 

 central organs and primary disk (hl) with funiculus 

 (/), to which the rhabdosomes (r) are attached by a 

 slender nemacaulus (n). Gonangia (f/) with young 

 siculae (s) are also present. x % (after Ruedeniann). 



Fkj. 207. 

 Glofisogriiptus (luadrimiicronatus Hall var. approximatus 

 Rued. Utica shale (Ordovician) ; Dolgeville, New York. 

 Synrhabdosome. x Vi (after Ruedeinann). 



Fio. 20S. 



Glossograptus quadrimucronatus (Hall) 

 var. apjyroximatus Rued. Utica shale 

 (Ordovician) ; Dolgeville, New York. 

 Young synrhabdosome showing central 

 disk and siculae. x »/i (after Ruedeniann). 



each theca with two long spines. Ordovician. lletiograptus Hall ; Lasiograptus 

 Lapworth. Ordovician. 



