423 Prof. M. Schultze on Polytrema miniaceum. 



Una {Orbitolitince) , Orbiculina, Alveolina, Siderolites, Calcarime, 

 Fusulince, &cc., which Carpenter has nowhere quoted. Even the 

 foundations of Carpenter's new system of the Foraminifera are to 

 be found expressed in my book (p. 12), in the following words : — 

 " In respect of the finer structure of the shell, the calcareous Fora- 

 minifera may be divided into two series, namely, into those which 

 have the shell perforated throughout with numerous fine aper- 

 tures or canals, and those in which the shell appears solid and 

 homogeneous.^'.,." Sufficiently transparent forms, or thin sections 

 of opake ones, when examined under the microscope by trans- 

 mitted light, either appear as colourless as glass or show a brown 

 coloration. To the latter belong all the solid and not finely 

 porous shells, and therefore the whole of the Miliolidte, the 

 Ovulina, Cornuspira planorbis, and the Peneroplidce." To the 

 same category I referred also Orhiculina and Sorites [Orbitolites), 

 although here I erroneously supposed their shell to be perforated 

 by small apertures, which, as Carpenter rightly asserts, they do 

 not possess. In opposition to these calcareous-shelled Rhizopods, 

 I placed the only siliceous-shelled species then known, the Poly- 

 morphina silicea*, observed by me at Ancona. Carpenter might 

 consequently have sought the first sure foundation of his family 

 Lituolidce also in my observations, which, however, appear to 

 have been quite unknown to him, as also my later communica- 

 tions upon a form resembling Nonionina, with a granular sili- 

 ceous shell f. The latter possesses a particular interest, inasmuch 

 as it contained in its interior numerous small globular shells 

 agreeing in structure with the large shell, and which, in accord- 

 ance with my observations on the reproduction of the Miliolidce: 

 and Rotalia, must be regarded as young. If these, therefore, 

 form a siliceous shell while still within the body of the parent. 

 Carpenter's notion that the siliceous particles of the shells of 

 Foraminifera are always derived from the surrounding sand J 

 must require modification. 



However, I must repeat that I welcome with pleasure the 

 classification of Foraminifera proposed by Carpenter, as a real 

 step in advance. That it is a natural and true expression of our 

 knowledge of the Foraminifera, which has made such consider- 



* Ueber den Organismiis der Polythalamien, pp. 9,11 & 61. Reuss 

 has since (Sitzungsber. der bohmischen Ges. der Wiss. zu Prag, Nov. 28, 

 1859) justly called attention to the fact that the species would be better 

 referred to the genus Bulimina, in which many sandy siliceous forms occur. 

 I leave it to Reuss to give the species a suitable name. 



t Nonionina silicea (Miiller's Archiv, 1856, p. 171, pi. 6. fig. 4) will 

 also have to receive a new name, and must be referred to the genus Lituolu 

 or Haplophragmiwn, Reuss. 



+ Introduction, &c,, pp. 47 & 140. 



