Nomenclature of the Foraminifera. 167 



2. Alveolina montipara, Ehrenb. Mikrogeol. pi. 37. x. c. figs. 5, C. 



3. Borelis sphaeroidea ?, Ehrenb. Monatsb. Berlin, 1842, p. 274 ; Mikro- 



geol. pi. 37. x. d. figs. 1-4. 



4. Borelis eonstricta, Ehrenb. Monatsb. Berlin, 1842, p. 274 ; Mikrogeol. 



pi. 37. x. d. figs. 5, 6. 



5. Alveolina prisca, Ehrenb. Monatsb. Berlin, 1842, p. 274 ; Mikrogeol. 



pi. 37. x. d. figs. 7-9. 



Nos. 2 and 5 differ from the others in being fusiform. No. 4 

 appears to be the same as the Fusulina Hyperborea, Salter, 

 Belcher's Arctic Voyage, 1855, ii. p. 380, pi. 36. figs. 1-3. 



We have examined (with the assistance of Mr. George West) 

 the structure of some Russian specimens equivalent to No. 3, 

 and find them to be really Alveolina, but having the following 

 interesting features, which Mr. G. West, who so well knows the 

 characters of Alveolina, having worked with Dr. Carpenter on 

 that subject, recognized and pointed out to us. In this palaeo- 

 zoic Alveolina the chambers have a simple character as compared 

 with those of the recent Alveolina : the transversely long cham- 

 bers are divided, by comparatively few secondary septa, into 

 rather large compartments, the gibbous roofs of which give a 

 faintly nodular appearance to the surface of the shell ; whilst 

 the recent Alveolina (see Dr. Carpenter's Monograph on this 

 species, Phil. Trans. 1856, pi. 28. fig. 23) has its chambers di- 

 vided into very numerous narrow oblong cells, giving a striated 

 appearance to the shell. An analogous difference in structure is 

 observed (as Mr. G. West has also remarked to us) between the 

 simple and the compound Orbitolites, as is well shown in Dr. 

 Carpenter's Monograph on the Orbitolites in the Phil. Trans. 

 1856, pi. 5. figs. 1 & 6. 



In some shells the septal apertures may be seen obscurely 

 as minute round openings ; but in other individuals the prin- 

 cipal aperture of the middle chambers forms a slit-like open- 

 ing, as shown by D'Orbigny. If the casts figured by Ehren- 

 berg bore small offshoots on the casts of the lateral portions 

 of the chambers, answering to intercommunicating passages, 

 they would then appear to correspond more exactly to the in- 

 terior of these curious Alveolina than they now do. 



Another old Alveolina is Ehrenberg's Borelis (Melonia) sph<e- 

 roidea (Monatsbericht. Berlin, 1843, p. 105; and Mikrogeol. 

 pi. 37. ix. a. figs. 1-3), obtained by him from the yellow " Me- 

 lonien-Jurakalk " of the Kaiserstuhl, Baden. In this specimen 

 the figured sections are those of the simple form ; but the exte- 

 rior has much of the aspect of a compound Alveolina. The 

 recent Alveolina Melo (from Karst, near Trieste) is figured, for 



