Weller — KinderhooJc 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 : — 



GLEN PARK. HAMILTON. 



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



Eunella compressa n. sp Eunella Uncklaeni (Hall). 



Atrypa spinoaa Hall - Atrypa spinosa Hall. 



Nucleospira minima u, sp Nucleospira concinna Hall. 



Nucula glenparkenais n. sp Nucula corbuliformis Hall. 



Nuculatia diversoides n. sp Nuculana diversa Hall. 



Macrodon aulcaUia n. so Macrodon hamiUoniae Hall. 



Schizodua appreasus (Con.) Schizodus appressus (Con.). 



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



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



Platyceraa erectoidea n. sp Flatyceraa erectum Hall. 



Platyeeraa evolutua n. sp Platyceraa thetis 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 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. CHOUTEAU. 



Orthothetes chemungensis (Con.) Orthothetes chemungensis (Con.). 



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



Delthyris miaaouriensis u. sp Delthyris solidirostris (White). 



Macrodon sulcatus u. sp Macrodon missourieiisis (M. & Q.). 



Modiola missouriensis n. sp Modiola northviewensis Weller. 



Tropidodiscus cyrtolites {H.a.\\) Tropidodiscua cyrtolites (Hall). 



Aside from these species, the presence of the crinoid genera 

 Agaricocrinus and Actinocnmcs, if these identifications be 



