Weller — Kinderhook Faunal Studies. 471 



origin of tlie northern Kinderhook fauna from the Chemung, 

 although the main portion of the Chouteau fauna is believed 

 to have originated or at least to have migrated from the far 

 west. 



EXPL.\NATION OF PLATES. 



Plale I. — 1, Zaphrentis sp. undet. — 2-3, Actinocrinus ? ap. uadet. 4. 

 Agaricocrinus ? sp. undet. — 5-6, Orthothetes chemimgensis (Con.), Two ped- 

 icle valves. — 7, Chonete» glenparkensis n. sp. — 8-12, Chonetes sp. undet. — 

 13-16, Eunella compressa u. sp., Brachial views of four individuals. — 17, 

 Atrypa spinosa Hall, Brachial view of the only specimen observed. — 18- 

 22, Spirifer yffersonensia x\. sp., two views of one pedicle valve and views 

 of three bracaial valves. — 23-26, Delthyris missouriensis u. ep., two views 

 of one pedicle valve and views of two brachial valves. — 27-28, Dtlthyris 

 suborbicularis n. sp., two views of a pedicle valve. — 29-30, Nucleospira 

 minima u. sp., views of a pedicle and a brachial valve. — 31-32, Ptyctodus 

 eastmani n. sp., two lateral views of a nearly perfect tooth. 



Plate II. — 1-3, Nucula glenparkensis n. sp., loft lateral views of three 

 complete specimens. — 4-5, Nuculana diversoides n. sp., lateral viewB of a 

 right and a left valve. — 6-9, Macrodon sulcatus n. sp., views of two left and 

 two right valves. — 10-11, Schizodus appressus (Con.), lateral views of two 

 right valves. — 12-13, Modiomorpha lamellosa n. sp., lateral views of two 

 left valves. — 14-17, Modiola missouriensis'ii. sp., lateral views of three right 

 valves and one left valve. — 18-19, Cypricardinia subcuneata n. sp., lateral 

 views of two right valves. — 20-23, Bellerophon ulrichi n. ep., dorsal views 

 of three individuals and a view of the aperture of a fourth. — 24, Bellero- 

 phon jefersonensis n. sp., dorsal view of a typical specimen. — 25-26, 

 Ptychomphalus missouriensis n. sp., lateral view of a nearly complete indi- 

 vidual, and an apical view of another less complete one, — 27-28, Naticop- 

 tis paucivolutus n. sp.. lateral views of two specimens, one of them show- 

 iing the aperture. — 29, Tropidodiscus cyrtolites (Hall), lateral view of the 

 most perfect individual observed. — 30-31, Platyceras glenparkensis n. 

 sp., right lateral views of two individuals. — 32-33, Platyceras evolutus n. 

 sp., right lateral views of two individuals. — 34-35, Platyceras erectoides 

 n. sp., right and left lateral views of one specimen. — 36-37, Orthonychia 

 ungiila n. sp., right lateral views of two individuals, the larger and straighter 

 one being the type of the species. — 38-31>, Orthoiiychia jefferiontnsis n. sp., 

 lateral views of two individuals. 



Issued, December 11, 1908. 



