134 



Report of the State Geologist. 



into fascicles of striae, and upon overgrowth of the whorls, are completely 

 resorbed. They occur normally at intervals, regularly increasing with the 

 growth of the whorls, so that there are about the same number, 9—11; on each 

 whorl. Their effect upon the later whorls is clearly marked, as at their 

 contact with such whorls the growth of the latter is obstructed so that the 

 umbilical margin of the whorl is crenulated or festooned, the edge extending 

 downward in the interval between the varices. Over the fifth whorl the 

 varices are lost, apparently becoming resolved into fine concentric lines which 

 make a broad concave curve forward, forming a narrow tongue-shaped lobe 

 at the shoulder of the whorl, thence being reflected into a narrow hyponomic 

 curve upon the flat periphery. 



Distribution. This species has been found in the calcareous concretions 

 in the vicinity of Honeoye lake, Ontario county and to the westward as far as 

 Conesus lake. It has not yet been seen in the Naples region, although it 

 is associated with species abundant there ; Mantle. Pattersoni, Probeloceras 

 Luih&ri, Pdheotrochus precursor, etc. Its horizon in the Portage formation 

 is the lower or shaly part of the series where all the species of the Intwwsci us 

 fauna are most fully developed. 



To the especial geologic interest in the presence of Clymenia in this 

 fauna, reference has been made in connexion with the original description of 

 this shell. Notwithstanding the various expressions assumed by this genus, 

 it has shown itself, wherever found in all its other occurrences, to be one of the 

 most reliable indices of the uppermost Devonian, so that the Clymenia-fauna 

 is a. well established upper terminal in the Devonian sections of Europe and 

 Asia. The investigations of Kayser, Munster, G umbel, Richter, Tietze, 

 Fbech, Siemiradski, Stur, Staciie, Hoernes, Karpinsky, Tschernysciiew , 

 Phillips, McCoy, Whidborne, Hebert, all establish this time-value for the 

 genus. But in its only known American occurrence the genus fails to corre- 

 spond with its position in the transatlantic sections. This fact is less 

 surprising than it would be if the genus here had attained airy great differen- 

 tiation or variety of expression. Its single species is found with a fauna of 

 such species as that witli which it is associated in the region (Westphalia and 

 Fichtelgebirge) of its most rapid evolution. 



It is, however,' a significant fact that this exiled representative of the 

 genus lias a certain goniatitine aspect and is one of the forms in which the 

 typical characters of the genus are not fully attained, as shown in the sim- 

 plicity <>f its suture Still in many of its structural features, its whorl- section 

 at maturity, its suture and the peculiar ornament of its immature whorls.it is 

 to be directly compared with the Cyrtocly'ffienia spinosa, Munster. 



