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98 CONTRIBUTION TO THE PALEONTOLOGY OF TRINIDAD. 



Remarks.— The majority of the Mesalias from Soldado Rock, Bed No. 2, 

 are somewhat further removed from Gabb's type of M . pumila than the variety 

 allentonensis. These correspond to Dr. White's description and figures of M. 

 nettoana from the Rio Maria Farinha beds in Brazil. The Soldado shells are of 

 practically the same size and are also ornamented with seven, or more rarely 

 eight, raised revolving lines. There is no question of the identity of the Soldado 

 and Brazilian shells. 



White 9 s original description. — "Shell moderately elongate; volutions ten or 

 more in number; distinctly and regularly convex, and marked by seven abruptly 

 raised revolving lines or slender ridges of nearly uniform size, and which are 

 separated by interspaces of about equal width with the ridges; the anterior side 

 of the last volution is marked by four or more revolving ridges similar to the 

 others; aperture moderately large, subcircular in outline. 



Length about 55 millimeters; breadth of the last volution 22 mm. 



Comparison of the Soldado with other forms. — On the front of the specimen 

 figured, the four revolving ridges at the very base of the last volution, mentioned 

 by Dr. White, have apparently been eroded away and the surface seems smooth, 

 but the lines show well on the other side of the shell. 



Height of largest fragment from Soldado 42 mm. Diameter of specimen 

 figured 20 mm. 



This variety would seem not to have been confined to the tropics; for in the 

 Paleontological Museum of Cornell University there is a specimen (No. 10122) of 

 Mesalia pumila Gabb from one mile north of Midway of Alabama of precisely 

 the same form and size as one of these Soldado shells, from which it differs only 

 in having one or two finer raised revolving lines. Otherwise they cannot be 

 distinguished. 



Locality. — Bed No. 2, Soldado Rock, Gulf of Paria. 



Geological horizon. — Midway Eocene. Equivalent to the Midway of Ala- 

 bama and of the Rio Maria Farinha beds in Brazil. 



Genus SOLARIUM Lamarck, 1799. 

 Solarium stephanephorum new species. Plate XIII, Figures 1, 2. 



Description. — Shell circular in outline, depressed conic, being rather more 

 flattened than the majority of the genus; whorls six, of which the uppermost are 

 small and nuclear; volutions ornamented by (a) transverse, oblique, faint lines 

 of growth, visible only with a lens; (6) coarser and finer raised spiral threads, 

 not beaded. The sculpture of the last volution consisting of (counting from the 

 suture towards the periphery) three or four fine, close-set spirals, bounded by a 

 more prominent spiral, these occupying the flat area of the whorl; then follows a 

 sloping area ornamented by two fine spirals followed by a stronger one, which 

 with two following form the rounded keel of the shell; under surface as far as 

 not obscured by the matrix is also ornamented by spiral threads. 



Height of shell 7, greatest diameter 17 mm. 



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