1896.] ^'^'^ [Smith. 



N., 6 W., section 18, southeast quarter of southeast quarter, near Moore- 

 iield ; Marshall shale, probably Warsaw division, Independence county, 

 13 N , 6 W., section 12, and Stone county, Blue mountain, 14 N., 11 W.; 

 Archimedes Limestone, probably of St. Louis age. Independence county, 

 13 N., 6 W., section 14. 



Marcj' (Expl. Red River of Louisiana, p. 187) cites this species from 

 Subcarboniferous limestone of Washington and Crawford counties, but 

 does not give the localities. 



Productus (Jlarginifera) splendens Norwood and Pratten. Productus 

 splendens Norwood and Pratten, Jour. Acad. Nat. Sci. Phil., 1854, 

 Vol. iii, p. 11, PI i. Fig. 5. P. loabashensis Norwood and Pratten, 

 Jour. Acad. Nat. Sci. Phil., 1854, p. 13, PI. i. Fig. 6. P. longisjnnus 

 Meek (non SoAverbj'), Final Report U. S. Oeol. Survey Nebraska,, 

 p. IGl. Margi/iifera splendens N. and P., Waagen. Palceontologia 

 Indica, Salt Range Fossils, Productus Limestone Fossils, Brachio- 

 poda, p. 714. 



This typical Upper Coal Measure and Permian species is a probable 

 ■descendant of Productus longispinus Sowerby, and so closely are these 

 two related, that for many j'ears they were considered identical. But 

 the Marginifera type of Productus seems to be confined to the Upper 

 Carboniferous and Permian, while P. longispinus Sow erhj is also found 

 in the Lower Carboniferous. The Arkansas specimens agree perfectly 

 with specimens from Indiana and Illinois. This species is very common 

 in the Coal Measures and Permian of North America, and probably 

 occurs also in Asia A very similar small species occurs in the Lower 

 Carboniferous limestone. Stone county, 14 N., 11 W., on Blue moun- 

 tain, but this lacks the ventral sinus, and has fewer spines, and there 

 fore probably belongs to the true P. longispinus Sowerby. 



P. {Marginifera) splendens N. and P. was found in the Upper Coal 

 Measures of Sebastian coianty, Arkansas, 8 N., 88 W., section 12, and 

 on Poteau mountain, Indian Territory, in strata that are either of upper- 

 most Coal Measure or of Lower Permian age. 



Productus pnnctatus Martin. Anoinites panctatus Martin, Petrif. Derh., 

 PI. 37, Fig. 6. Productus punctatus Martin, Davidson, J/on. Brit. 

 Garb. Brachiopods, p. 172. 



This species is cosmopolitan in the Coal Measures and Lower Carbon- 

 iferous, although more common in the latter horizon. It is very sel- 

 dom that the shell is so preserved that the internal characteristics can 

 be seen. In the figured specimen the arm impressions, adductor muscle 

 scars, median septum, and the cardinal process are all perfectly pre- 

 served. 



The dorsal valve is somewhat squarer than those figured by Davidson 

 {Mon. Brit. Garb. Brach., PI. 44, Figs. 9-17). but the internal markings 

 are the same in every detail, except that Davidson's figure makes the 



