166 Messrs. W. K. Parker and T. R. Jones on the 



1830. Fusulina cylindrica, Fischer, Oryctographie du Gouvernem. de Mos- 



cou, p. 17, pi. 13. figs. 1-5. 

 1830. Fusulina depressa, Fischer, ibid. figs. 6-11. 

 1815. Fusulina cylindrica, D'Orb. Geol. Russ. ii. (Pakeont.) p. 15, pi. 1. 



fig. 1. 

 1846. Fusulina cvlindrica, D'Orb. Foram. Foss. Vienne, p. 112, pi. 21. 



figs. 15-17. 

 1859. Fusulina cylindrica, Eichw. Leth. Rossica, 5th livr. p. 349. 



In the 'Geology of Russia and the Ural Mountains/ vol. ii. 

 p. 15, pi. 1. fig. 1, D'Orbigny figured and described the Fusulina 

 cylindrica, and again in his ' Foram. Foss. Vienn/ p. 112, pi. 21. 

 figs. 15-17; and it may be noticed that the figures show a re- 

 markable longitudinal, slit-like septal aperture, and that his 

 description also points to a N onion ine style of shell. 



In his great work * on fossil microscopic remains, Ehrenberg 

 has illustrated several varieties of Alveolina from the Carboni- 

 ferous Limestone of Russia under the generic names " Alveo- 

 lina " (the fusiform varieties) and " Borelis " (the more globular 

 forms) : most of these he recognized in 1842 and 1843f, com- 

 paring them with the Melonia spharoidea of Blainville ; and he 

 stated also that Fusulina was a closely allied shell (Bericht. 1842, 

 p. 274). He has also, in the ' Mikrogeologie/ figured several 

 natural siliceous casts of a shell, which he also terms " Alveo- 

 lina " and " Borelis," according to their fusiform or spherical 

 shapes, but which at first sight appear to belong to a Noniouine 

 Foraminifer, such as D'Orbigny described his "Fusulina" to 

 be. These casts indicate the presence of a large slit-like aperture 

 in the shells to which they belonged; and the lateral portions 

 of the chambers taper off more or less rapidly. Of this Nonio- 

 nine form Ehrenberg's figures illustrate five varieties, namely — 



1. Alveolina prisca, Ehrenb. Mikrogeol. pi. 37. XI. figs. 1, 2 (the shell of the 



Alveolina of this name is also figured on the same plate). 



2. Borelis labyrinthiformis, Ehrenb. Monatsb. Berlin, 1843, p. 106; Mikro- 



geol. pi. 37. xi. fig. 3. 



3. Borelis Palreolophus, Ehrenb. Mikrogeol. pi. 37. xi. figs. 4, 5. 



4. Borelis Pahcophacus, Ehrenb. Mikrogeol. pi. 37. xi. fig. 6. 



5. Borelis Palreosphaera, Ehrenb. Mikrogeol. pi. 37. XI. figs. 7, 8. 



Four of these vary merely in the gradually greater compres- 

 sion of the shell (their order, if arranged according to the amount 

 of compression, being fig. 1, fig. 7, fig. 6, and fig. 4). 



Ehrenberg's Alveoline shells from the Carboniferous Lime- 

 stone are — 



1. Borelis princeps, Ehrenb. Monatsb. Berlin, 1842, p. 274; Mikrogeol. 

 pi. 37- x c. figs. 1—4. 



* Mikrogeologie, von C. G. Ehrenberg. fol. Leipzig, 1854. 



t Monatsberichte Akad. Wissensch. Berlin, 1842, p. 273; 1843, p. 105. 



