132 



Report of the State Geologist. 



protoconch agrees fully with that ascribed by Branco to the only other 

 species of the genus in which the primitive shell has been observed (O. cf. 



102 



Figures 102-i04. CyTtoclym6nianeapoliia.no.. Fig. 102. The protoconch. x 25. Fig. 103. Side view of the proto- 

 conch with portion of the nepionic shell x 25. Fig. 104. Similar view of another specimen showing the striations 

 extending to the neck of the protoconch. x 25. 



undulata, Minister),* but it is a notable fact that the size of this shell in 

 O. neapolitana is very much greater than, not far from thrice, that of the 

 European species. In view of this fact not infrequent among the Groni- 

 atitinse, we quote the expression of Hyatt, that " the whole range of the 

 transformations of the Goniatitinae are paralleled in this short series" 

 (Clynieninae). Branco cites as an important feature of the Clymenia proto- 

 conch, the absence of depressions at its neck such as occur in all 

 ammonoids, and which Hyatt has construed as remnants of the umbilical 

 perforation. We can not say that our specimens clearly substantiate this as a 

 feature characterizing the group. These depressions may possibly be some- 

 what more obscure in O. neapolitana than in its 

 associated goniatites, but not to such a degree as to 

 attract attention without previous suggestion. The 

 protoconch is much narrower at its distal extremity 

 than on the opposite surface, which appears to be 

 rather broadly flattened. This is shown in views 

 represented in figures 102—104. 



The Early Whorls. The cross-section of the first 

 whorl shows its narrow anarcestian outline, a form 

 which is only very gradually lost by the increasing 

 definition of the ventral flattening, so that the vertical 

 elongation of the whorl section manifests itself rather 



Figaro 105 Cyrloclymenia neo- . 



poutana. .Sections of the early rapidlv after the close of the fourth volution. The 



wuoils. x 25. - * 



second and third whorls are broad-backed and rounded, 

 the narrow peripheral flattening manifesting itself first upon the fourth whorl, 

 occupying the median portion of a broad ventral curvature. 



Palaoonlogruphica, vol. xxvii, pi. vii, fij. III. 



