Weller — KinderJiook 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: — 



GLBN PARK. HAMILTON. 



Orlhothetes chemungensis (Con.j Orthothetes chemnngensis (Con.). 



Sunella compreasa n. sp Eunella lincklaeni (Hall). 



Atrypa spinosa Hall .- Atrypa spinosa Hall. 



Niw-leospira minima n. sp N'ucleospira concinna Hall. 



Nucnla glenparkenais n. sp Nueula corbuliformis Hall, 



Niiculana divtrsoides n. sp N'uculana diversa Hall. 



Macrodon sulcatus n. so Macrodon hamiltoniae Hall. 



Schizodua appreaaua (Con.) Schizodus appressus (Con.). 



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



Cypricardinia aubcuneata n. ep Cypricardinia indenta (Con.). 



Platycf.raa 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 Produclus 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 liuiestone and in other contemporaneous for- 

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

 as the Devonian element, and consists of the following species 

 with their analogues : — 



GLEN PARK. CHOUTEAU. 



Ortkothetes chemungensia (Con.) Orthothetes chemungensia (Con.) . 



Chonetea glenparkenais D. sp Chonetes loganiN. & P. 



Delthyria miaaouriensis n. sp Delthyris solidirostris (White). 



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



Modiola miaaouriensis n. sp Modiola northvieioensis Weller. 



Tropidodiacus cyrtolites (Hall) Tropidodiscua cyrtoUtea (Hall). 



Aside from these species, the presence of the crinoid genera 

 Agaricocrinus and Aclinocrinus^ if these identifications be 



