168 Proceedings of the Royal Irish Academy. 



with the following diagnosis, in which the arenaceous constitution of tlie test 

 is not referred to.'' 



" Bulimina jpob/s/ropha. Distinguishes itself from all other species hy 

 the great number of its convolutions, and by its slender elongated-egg 

 configuration. It is 1-1"5 mm. high, rounded off above, obtusely (bluntly) 

 pointed ; 9-10 obscure convolutions, each consisting of three moderately 

 arched chambers separated by slender but distinct septa. The upper 

 chambers, especially the last, extremely arched. Ou the inner edge of the 

 last chamber is the aperture, as a small semicircular cutting-out. 



" Eare in the Planer chalk of Weisskirchlitz." 



In 1854 the species was described anew by Schultze as Pol i/morphina 

 silicca.*' It must be borne in mind that at this time the arenaceous Foramini- 

 fera had not received tlie attention, separation, and classification which 

 resulted later from the work of Brady, Parker, and Jones. The diagnosis 

 of Schultze was as follows : — 



" Polymorphina silicea nov. spec. A botryoid (grape-cluster-like}, 

 sometimes slightly compressed sliell, on which only the last- formed, rather 

 strongly prominent chambers arc distinctly \ isible ; the small older ones 

 are covered up. The shell is yellow in colour, marked by many quite 

 irregular and non-perforating depressions, and is composed for the most part 

 of silica. A single, large, round aperture is situated ou the prominent part 

 uf the last chamber, through which the animal protrudes numerous fine 

 pseudopodia. Greatest diameter of the ."hell, 0'2-lniin. 



" This remarkable species, of which 1 found one living and many dead 

 specimens at Ancona, and which is distinguished fiom all hitherto known 

 Foraminifera by its siliceous cuirass, I have left in the genus Polymorphina, 

 on account of its jirecisely similar construction to the other species of the 

 genus, although the different anomalous) chemical constitution of the shell 

 might properly justify the institution of a new one. I have not hitherto been 

 able to establish (identify) the presence of silica in the shell in any other 

 species of this genns." 



Schultze came to the erroneous conclusion that the sand-grains forming 

 the test were not gathered from its suiToundings by the organism, but were 

 secreted by the animal itself, in the same manner as the plates of Dilllugia. 

 He goes on : — 



"That the silica (which is identified by its complete insolubility in 



*• A. E. Rsu&s ; " Die Versteinerungen der Bohmischen Kreideformation." 

 Stuttgart, 1845-C, Part 11 (1*46). p. 1U9, PI. xxiv, fig. .'.3. 



** M. S. .Schtiltze: " Ueber den Organismus der PolythnUniien (Foraminiferen)." 

 LviprJii. 18."»4, p. fit, PI. vi. fis;». lU, 11. 



