PRODROMITP]S. 37 



of Osage age. Tliis liorizon may then be correlated with the Chouteau 

 limestone of central Missouri. 



A fourth specimen of Prodromites (/orhi/i was studied in the collection 

 of Fred. IJraun, of Brooklyn, N. Y. ; it came from the goniatite beds of the 

 Kinderhook of Rockford, Ind., associated with Prolccanifes lyoni Meek and 

 Worthen, Aganides rotatoritis de Koninck, Muensteroceras otveni Hall, M. 

 2)araUelum Hall; thus it is certainly in the zone oi Aganides rotatorius of the 

 Tournaisian horizon of the Lower Carboniferous (Mississippian or Dinantian). 



A fifth specimen of the genus, No. 6223, belongs to a new species, 

 (P. jyrfematurHS Smith and Weller) ; it came from the goniatite beds of the 

 Kinderhook of Rockford, Ind. 



Occurrence. — Since this genus occurs in the same horizon, in rocks 

 of different lithologic character, and in three localities, separated by hun- 

 dreds of miles, it may be considered as characteristic of the Kinderhook or 

 Chouteau horizon of the Lower Carboniferous, equivalent to the lower part 

 of the Tournaisian division of the European Dinantian formation. At 

 present, Prodromites is not known outside of America, and but three species 

 are known, in the Mississippi Valley region, from the three localities 

 mentioned. 



Prodromites gorbyi Miller. 



PI. XXIII; PI. XXV, figs. 1, 2. 



1891. Goniatites gorhji., S. A. Miller, Advance sheets Seventeenth Ann. Rept. Geol. 



Surv. Indiana, p. 90, PI. XV, fig. 1. 



1892. Goniatitea gorhyi, S. A. Miller, Seventeenth Ann. Rept. Geo). Surv. Indiana, 



p. TOO; PI. XV, fig. 1. 

 1901. Frodronutes gorhiji. Smith and Weller, Jour. Geol., Vol. IX, No. 3, p. 259, 

 PI. VI, fig. 1; PI. VII, fig. 1; PI. VIII, figs. 1 and 2. 



Neither the description nor the figure of this type given by Miller is 

 accurate, the drawings of the septa being nmch too generalized. The form 

 is laterally compressed, involute, discoidal, with very narrow umbilicus. 

 The abdomen is narrow and surmounted by a high hollow keel, which, 

 however, is not usuall}^ preserved. Where the keel is broken away the 

 abdomen is narrow, less than a millimeter wide, with angular edges. The 

 sides are smooth, devoid of constrictions, ribs, or other ornamentatioir, so 

 far as could be determined from the easts. 



The septa are complex, ceratitic, with many lobes and saddles. The 



