﻿NORWOOD AND PRATTEN ON PRODUCTI. 11 



Geological Position and Locality. — This specimen was found by Mr. H. A. Ulffers, 

 •among the debris from rocks collected at Grayville, Illinois, where it occurs in the 

 upper part of the coal measures. 



Explanation of the Figures. — PI. I., Jig. 4, a. View of the dorsal valve, with so 

 much of the prolongment as is preserved. 



Fig. 4, b. The beak. 



Fig. 4, o. View of the transverse bands of the visceral part, magnified four times. 

 Collection of H. A. Ulffers. 



Section IV. 

 PRODUCTI SEMIRETICULATI. 



P. Boliviensis, A. iV Orbigny. De Koninck " On the Genus Productus," PI. VIII., 

 %. 2. 



Geological Position and Locality. — Found twelve miles North-West of Richmond, 

 Missouri, in limestone, where it is associated with fossils belonging to the coal 

 measures. H. Pratten's collection. 



P. semireticulatus, Martin sjp. — De Koninck's Monograph, PI. VIII., fig. 1, pi. 

 IX., fig. 1, and pi. X>, fig. 1. 



Geological Position and Locality. — This species is very generally distributed in the 

 mountain limestone of the Western States. Illinois State Collection. 



P. carbon arius, de Kon. — De Koninck " On the Genus Productus." PI. V., fig. 4. 

 Geological Position and Locality. — This species is very common at Fountain Bluff, 

 Illinois, in the mountain limestone. Illinois State Collection. 



P. costatus, Sowerby. — De Koninck's Monograph. PI. VIII., fig. 3, pi. X., fig. 3, 

 and pi. XVIIL, fig. 3. 



Geological Position and Locality. — This fossil, although belonging to the mountain 

 limestone of Europe, is, in the Western States, a characteristic fossil of the coal 

 measures. It occurs in limestone at Caseyville and Belleville, Illinois, and at Char- 

 boniere, St. Louis county, Missouri. 



P. Flemingii, de Kon. — De Koninck " On the Genus Productus." PI. X., figs. 2 

 and 3. 



Geological Position and Locality. — This fossil occurs in the mountain limestone of 

 Hardin county, Illinois ; Leavenworth, Indiana, and Burlington, Iowa. 



P. splendens, nob. — PI. I, fig. 5, a, by c, d. 



Shell small, transverse, the cardinal edge being the widest part ; somewhat inflated ; 

 but with its visceral and anterior parts rather flattened. Ears very much extended, 

 each bearing, generally, two thick tubes, and are a little enrolled. The surface is 



