Recent and Fossil Foraminifera. 333 



attention, but which, in the earlier stages of our examination, were set 

 aside and regarded as probably referable to the genus Planorbulina. 

 After a considerable number of specimens in all stages of growth had 

 been collected, we found that they presented features which could 

 not be correlated with that genus, and as a result of careful ex- 

 amination, including the cutting of sections of the test in various 

 planes, we are enabled definitely to identify our specimens with an 

 interesting type, of which the first, and we believe only, record 

 appears as above from the pen of the late Charles Schlnmberger. 

 As his paper has received little or no notice, we cannot do better than 

 quote its essential parts, which are as follows : — 



" The species was discovered by " mon ami M. Linder, Inspecteur 

 General des Mines," in the rubbish from borings in the Dept. of the 

 Gironde. 



" Test discoidal, thickened in the centre, composed of a single 

 layer of numerous chamberlets disposed circularly around a central 

 chamber and on the same plane. The partition-walls of each circle 

 of chambers extend towards the centre above the already formed 

 chambers. This calcareous envelope is traversed by coarse per- 

 forations which communicate directly with the inner chambers. 

 He describes two forms, A and B. 



Linderina Brugesii Scklumb, sp. n. 



" Form A. — A transverse section made perpendicularly to the 

 circumference, shows in the centre a large primordial chamber, 

 spherical, and accompanied on the right and left, and on a more or 

 less curved line, by a series of chambers which grow gradually 

 taller. They are invested above and below by a calcareous deposit 

 which is thicker at the centre than at the periphery ; this massive 

 formation is produced as is seen by the sutural lines, by the pro- 

 longation, towards the centre, of the walls of the chambers. 



" These walls are coarsely perforated, and these perforations are 

 continued in a straight line, increasing slightly in diameter, across 

 the whole thickness of the calcareous envelope to reach the surface 

 of the test, and thus establish a communication between all the 

 chambers and the exterior. The section being rather thick, one 

 sees in the outermost chambers unevenly distributed openings by 

 which the adjoining chambers of the same ring communicate with 

 one another. 



" In a section at right angles to the last (horizontal) it is impos- 

 sible to see all the chambers from the megalosphere outwards, 

 because they are generally situated on a concave surface. One 

 sees by a higher magnification that the wall of all the chambers is 

 continuous right round the test without any sutures, and forms 

 the chambers by its waviness. 



" Form B only differs from Form A in that it is microspheric. 



June 21st, 1911 z 



