544 Transactions of the Society. 



the Tcrmian seas it was scarce, and apparently was still more rare in 

 Carboniferous times, when the arenaceous types were in the ascendant. 

 Only one undoubted example of this species was obtained from the 

 material searched, but with the exception of exhibiting a mineraliza- 

 tion corresponding to the much older formation from which it was 

 obtained, it does not materially differ from the examples of later age. 

 It is a minute shell with a clear calcareous appearance. Test slightly 

 compressed laterally. The chambers, which are elliptical in shape, 

 number six, in a curved linear series, and increase somewhat rapidly 

 in size in the direction of growth. Septal lines marked by oblique 

 and rather deep constrictions. Primordial cud apiculatc. Length 

 1/28 in. 



Distribution. — Only known from the "D" Limestone, Tipalt; rare, 



FamUy EOTALIDiE. 



Sub-family Rotalinae. 



Genus Patellina, "Williamson. 



Patellina Brachjana, sp. nov. Plate IX. JBgs. 22-25. 



Test free ; conical ; trochoid ; primordial end obtusely pointed ; 

 transverse section circular; length equal to two or three times the 

 diameter of the test ; inferior side slightly concave ; external surface 

 limbato, exhibiting numerous annular, semi-annular, or spiral whorls of 

 raised shell-substance alternating with lines of depression ; depressed 

 areas bridged by minute crenulations of the test, which, as raised 

 transverse lines, connect the limbate septal ridges. Internal structure 

 a simple, undivided and continuous spiral chamber (or alternating 

 semi-annular chambers ?). Chamber cavity compressed. Umbilical 

 region extending almost the entire length of the shell and of nearly 

 equal diameter throughout, filled with uniform shell-substance. Con- 

 volutions of spire varying from five to twelve ; average number ten. 

 Aperture a narrow slit, extending from the periphery to the umbihcal 

 margin. Umbilicus depressed ; or, frequently, marked by a raised 

 lip extending from the umbihcal termination of the orifice, forming a 

 low, semich'cular wall defining the central portions of the test. Length 

 about 1/38 in. ; diameter, at base, 1/100 in. 



This is, perhaps, the most interesting find in the present group of 

 new forms. The oldest record of Patellina has not, hitherto, extended 

 beyond the Cretaceous formations, in which, as well as in rocks of early 

 Tertiary age, the genus was represented by shells of relatively large size 

 and complicated structure. The common recent species, P. corrugata, 

 exhibits to some extent the subdivision of chambers by secondary 

 septa, so remarkably developed in some of the earlier Ibnns. The 

 Carboniferous examples are of a simpler type, and do not possess any 

 subdivision of the chamber cavities. Mr. H. B. Brady, in the 

 " Challenger Foraminifera," describes a new recent species, Patellina 

 campani^ormis, which shows the same simple and undivided chamber 



