ON THE GENUS POLYMORPHINA. 217 
Globulina equalis, D'Orbigny, 1846, For. Fos. Vien. p. 227, pl. 13. figs. 11, 12; Reuss. 1851, Zeitsch. 
deutsch. geol. Gesell. vol. iii. p. 81. 
G. inflata, Reuss, ibid. p. 81, pl. 6. fig. 45; Bornemann, 1855, ibid. vol. vii. p. 344. 
G. equalis, Bornemann, ibid. p. 344. 
G. globosa, Reuss, 1861, Sitzungs. Akad. Wissensch. vol. xliv. p. 318, pl. 3. fig 3. 
- Polymorphina globosa, Karrer, 1865, Sitzungs. Akad. Wissensch. vol. lii. p. 497, pl. 1. fig. 12. 
-P. equalis, Reuss, 1867, ibid. vol. lv. p. 72, no. 2; Karrer, 1868, ibid. vol. lviii. p. 172; Bunzel, 1869, 
Jahrb. k. k. geol. Reichsanstalt für 1859, p. 208. 
Characters—Shell (typical) subspherical or oval, somewhat produced at the apex, 
broad and rounded at the base. Chambers few, compact, and overlapping. Sutures 
marked by lines er neither excavated nor depressed externally. Surface smooth. 
Long diameter about 4; inch. 
Polymorphina E is, perhaps, as definite in its typical characters and as apt for 
technical description as any member of the group; still some latitude must be allowed 
in the terms employed for its diagnosis. D’Orbigny’s * Modèle” represents a nearly 
globular shell, and may be taken as representing the normal form. Our first list of 
synonyms refers to specimens deviating in no striking particular from this standard. 
Perhaps the commonest modification is to be found in the compressed varieties, of 
which the best-known and most generally recognized is the Globulina equalis of the 
same author (Plate XXXIX. figs. 2, c, d) ; and the second portion of the above synonymy 
comprises (together with G7. equalis) a number of subvarieties differing from the type 
and from each other chiefly in the amount of lateral compression. 
Dr. Karrer's Polymorphina gibba, var. orbicularis, on the other hand, instead of being 
compressed laterally, is shortened in the direction of its axis, and, whilst preserving a 
cireular transverse section, is elliptical in its lateral aspect, the longer diameter being the 
horizontal one. 
Specimens like Dr. Egger's subvarieties 8, y, and à are often to be met with, and 
represent individuals in which the segments are unequally gibbous and not very regularly 
- combined, rather than groups sufficiently stable in their characters for separation, even 
under varietal names, from the type. 
Globulina punctata, D'Orb., we can regard only as representing a thin-walled condition 
in a shell of the common type. The extent to which the minute foramina in the 
chamber-walls are visible depends in great measure on the thickness and age of the shell. 
- Old and opaque specimens seldom exhibit the perforations, which, notwithstanding, are 
still present, as may be seen under favourable circumstances, like the fractured edge 
- shown at Plate XL. fig. 12,f. Just the same appearance may be observed in many other 
clear-shelled forms besides P. gibba. 
The shape of the anterior portion of the shell differs a good deal in different indi. 
viduals. In some it is acuminate, and the orifice is situate in a mamillate protuber- 
ance; in others it is truncate, and the general aperture is “flush ” with the body of the 
shell. In rare examples the orifice is turned inwards, like that of an entosolenian 
Such trifling divergences from a normal type cannot be looked upon as safe ground 
