WeJler — Kinderhook Faunal Studies. 463 



relatives, this relationship must be considered as genetic. 

 The following list of species with their Hamilton analogues 

 are present in the fauna : — 



GLKN PARK. HAMILTON. 



Orthothetes chemungensia (CJon.; Orthothetes chemungensis (Con.) . 



Eunella compreasa n.^p • Eunella lincklaeni (Hall). 



Atrypa spinosa Hall — Atrypa spinosa Hall. 



Nue.leospira minima n. sp Nucleospira concinna Hall. 



Nucula glenparkentis n. sp Nucula corhuliformis Hall. 



NxiGulana diveraoides n. sp Nuculana diveraa Hall. 



Macrodon aulcatus n. sp Macrodon hamiltoniae Hall. 



Schixpdua appreaaua (Con.) Schizodus appresaua (Con.). 



Modiomorpha lamelloaa n. sp Modiomorpha concentrica (Coo.). 



Cypricardinia auhcuneata n. sp Cypricardinia indenta (Con.). 



Platyceraa erectoidea n. sp Platyceraa erectum Hall. 



Platyeeraa evolutua n. sp Platyceraa thetia Hall, 



The pre-ence of the species of the genus Ptyctodus is 

 another characteristic of the fauna strongly suggestive of its 

 Devonian age ; although this genus has never been recognized 

 in the Hamilton faunas of New York, it is not an uncommon 

 member of the later Devonian faunas of the Mississippi valley, 

 and has never been recorded from any fauna of unquestioned 

 Mississippian age. The entire absence from the fauna of all 

 members of the genus JProductus is another notable charac- 

 teristic which suggests its Devonian age. 



Notwithstanding this unquestioned strong Devonian aspect 

 of the Glen Park fauna, there are several species which point 

 to a relationship with the Kinderhook fauna of Southern and 

 Central Missouri, the fauna which has its typical expression 

 in the Chouteau limestone and in other contemporaneous for- 

 mations. This Chouteau element in the fauna is not so large 

 as the Devonian element, and consists of the following species 

 with their analogues : — 



GLEN PARK. CHOUTKAU. 



Orthothetes chemungensia (Con.) Orthothetes chemungenaia (Con.). 



Chonetea glenparkensis n. sp Chonetes logani N. & P. 



Delthyria miasourienais u. sp Delthyria solidiroatria (White). 



Macrodon aulcatua n. sp Macrodon miasouriensia (M. & G.). 



Modiola miasouriensia n. sp Modiola northviewenais Weller. 



Tropidodiacua cyrlolitea (Hall) Tropidodiscua cyrtolitea (Hall). 



Aside from these species, the presence of the crinoid genera 

 Agaricocrinus and Actinocrinxts^ if these identifications be 



