﻿ENDOTHYRA. 



93 



Involtjtina lobata, Brady, 1869. Eeport Brit. Assoc., Exeter Meeting, pp. 379, 382. 

 Involuta lobata, Brady, 1871. (In Young and Armstrong's Catal.) Trans. Geol. 



Soc. Glasgow, vol. iii, Stippl., p. 141. 

 Endotiiyra Bowmanni, Brady, 1873. Mem. Geol. Survey Scotland ; Expl. Sheet 23, 



pp. 63, 95, &c. 



Characters. — Test depressed, usually consisting of two or three oblique convolutions, 

 of which but little more than the last is visible on the exterior. Margin thick, rounded, 

 lobulate j septal lines depressed. Segments inflated ; variable in number, usually from 

 seven to ten in each whorl. Aperture single, simple. Diameter, to inch or more 

 (0*6 mm. to 1*3 mm.). 



The figure given by Professor Phillips in his paper " On the Remains of Microscopic 

 Animals in the Rocks of Yorkshire, " he. cit., and the very partial description appended 

 to it, form, as already stated, the first record, of any paleeontological value, of the occurrence 

 of Foraminifera in the Carboniferous beds of England. The description amounts to very 

 little, and the figure which represents a nearly complete horizontal section is not given 

 with much detail. But it must be taken for what it is worth ; and the comparison with 

 a series of sections of determined forms, made for the purpose of distinguishing the species 

 present in transparent slices of the harder limestone rocks, leaves little doubt that it is 

 referable to the particular modification described by myself some years ago, under the 

 name Involutina lobata. The horizontal section represented in PI. V, fig. 4, corresponds 

 very closely with Professor Phillips's drawing. 



I have recently received, through the kindness of Dr. Meek, of Washington, some 

 pieces of Sub-carboniferous Limestone from Southern Indiana containing the Botalia 

 Baileyi of Professor James Hall, in point of fact almost entirely composed of that species. 

 Detailed examination has convinced me that, notwithstanding the somewhat stouter 

 proportions presented by the American specimens, they do not differ in any important 

 character from Endothyra Boivmarii. I regret to have to sacrifice a specific term given 

 in memory of one whom all microscopists delight to honour, but under the circumstances 

 the name employed by Professor Phillips takes precedence of the others. 



Endotiiyra Boiomani may be accepted as the best type of the genus. Not only was 

 it the first described and first named, but morphologically it occupies about a central 

 place in the range of modifications which the series presents : it is one of the largest in 

 point of size, as it is also one of the most widely distributed species of the entire group. 



The Indiana limestone before alluded to is a very remarkable microzoic rock. In 

 appearance it is not unlike a whitish oolite, but almost every individual grain is a specimen 

 of this rotaliform foraminifer; there is indeed scarcely enough of the calcareous matrix 

 to cement the fossils permanently together. The mass crumbles down readily between 

 the fingers, and the disintegrated grains are clean enough for mounting without further 

 preparation. The average size of the American specimens is greater than any hitherto 



