'ON THE GENUS POLYMORPHINA. 229 
again in the Lower Oolite of Somerset, in the Upper Oxford Clay (Oxford), in the Kim- 
meridge Clay ( Kimmeridge), and in the Cretaceous system of North Germany. Since the 
Secondary period it has been even more generally distributed, being common in the Sep- 
taria-clays and Miocene deposits of Central Europe, and occurring in the Tertiary beds 
of New Zealand. Itis present in the Lower Crag of Suffolk, in the Upper Crag of Nor- 
folk, and in the Postpliocene (Glacial) clays of Norway and the west of Scotland. - 
In the living state it is cosmopolitan, especially common in the seas of temperate lati- 
tudes, but extending even into the Arctic regions. Although affecting shallow water, it 
is one of the three species of Polymorphina dredged by Prof. Sars in 300 fathoms; but 
this depth must be regarded as an exceptional range. 
POLYMORPHINA REGULARIS, von Münster. (Plate XL. figs. 13, «-e.) 
Polymorphina regularis, von Münster, 1838, fide Roemer, Neues Jahrb. für Min., Jahrg. 1838, p. 385, 
pl. 3. fig. 21; Philippi, 1844, Beiträge zur Kenntniss d. Tertiärverst. nord-west. Deutsch. pp. 41, 
70; Karsten, 1849, Verzeichn. d. Rostock. Verst. a. d. Sternberger Gestein, p. 8; Reuss, 1855, 
Sitzungsb. k. Akad. Wissensch. vol. xviii. p. 247, pl. 7. figs. 70-73; id. ibid. vol. 1. p. 38, pl. 3. 
figs. 11, 12, pl. 4. fig. 1. 
P. regularis, var. Nysti, Reuss, 1863, Bullet. de Acad. roy. de Belgique, vol. xv. p. 162, pl. 3. fig. 42. 
P. lingulata, Stache, 1865, Novara-Reise, vol. i. 2' Abtheil., Palüont. von Neu-Seeland, p. 255, pl. 24. 
fig. 1. ; 
TP. ERIS id. ibid. p. 258, pl. 24. fig. 5. 
P. dispar, id. ibid. p. 261, pl. 24. fig. 8. 
P. gigantea, id. ibid. p. 262, pl. 24. fig. 9. 
.. Oharacters.—Shell oblong, irregularly biconvex, broadest in the upper half, tapering 
towards both base and apex; periphery thin and produced but not carinate. Septal 
lines marked by slight constriction. Chambers numerous, long, oblique. Surface 
smooth. Length j inch. 
_ Notwithstanding certain differences that at first sight appear formidable, there can be 
little doubt that Polymorphina regularis is very closely allied to P. anceps. Prof. Reuss, 
in his later papers, has placed the two under the same heading, giving P. anceps pre- 
cedence, and describing them as the extreme modifications of the same series. The 
relationship i is not very manifest; but the careful study of such a set of figures as that 
given by Dr. Stache (op. cit. pl. xxiv. figs. 1-5, 8, 9) is sufficient to show that there 
is no real boundary-line between the two, and, further, that, on the side of P. regularis, 
there are still more aberrant specimens, like P. marsupium, tache, which must be 
taken into the same group. It is, however, consistent with the plan adopted in the pre- 
sent paper, and it is certainly more convenient, to recognize both as subtypes for separate 
congeries of specimens having average characters very distinct from each other. The 
same reasons that have led Prof. Reuss to merge these two varieties must, if uniformly 
pursued, result in the entire disuse of subdivisions in most of ¡the generic or typical 
groups of Foraminifera. In the case of the genus Polymorphina there is, as we have 
already stated, no single reputed “species” that does not inosculate with one or more 
other groups of similar zoological value; but whilst this fact must be borne in mind, it 
does not affect the necessity for recognizing g the more important and characteristic modi- 
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