THE FAMILY LITUOLID^ 155 



examples came from the Carboniferous limestone of 

 England and Scotland. The author has described 

 the same form from the Eh^tic of Somerset. 

 Garhoniferous. BJuetic. (Plate 8, fig. M.) 



GrENUS InrolKtina, Teequem. 



Test discoidal to conical ; consisting of a coiled 

 tube wound spirally either in a plane or to form a 

 hollow cone. When conical the hollow inferior 

 surface is filled in with exogenous shell-growth ; 

 when discoidal both surfaces are thickened with 

 exogenous tubercles. The tube is sometimes 

 partitioned at intervals by incomplete septa. Aper- 

 ture circular or slit-like. Shell-wall more or less 

 perforate. Jurassic. 



Example. — I. Bemesiana, Chapman, ' Journ. 

 Linn. Soc. Lond., Zool.' vol. xxviii. 1900, p. 29, pi. 

 5, figs. 5, a-c. 



This form has a conical test, depressed, and 

 consisting of a simple coiled tube of about five 

 whorls ; the sutures distinct. The inferior surface 

 is slightly convex, and covered with papilhe of 

 exogenous shell grow^th, excepting the last wdiorl, 

 which is marked on the periphery with distinct 

 furrows at right angles to the edge. The test is 

 finely perforate on the inner parts of the tubes, and 

 calcareo-arenaceous on the outer. The aperture 

 opens on the inferior side of the test. Tipper 

 Jurassic (TitJionicm), of Nesselsdorf, Austria. (Plate 

 8, figs. 1, /, /.) 



