218 MESSRS. BRADY, PARKER, AND JONES 
for the subdivision of an otherwise compact group. We are conscious that the principle 
we have adopted in endeavouring to simplify the nomenclature of the genus might be 
carried legitimately much further, and that the compromise arrived at has been in a 
measure influenced by motives of convenience; but the primary consideration of natural 
relationship has been steadily kept in view. 
Distribution.—The range of Polymorphina gibba, geological and geographical, is very 
extended. It appears as a cretaceous fossil in Bohemia, and we have specimens from the 
Kimmeridge Clay of the South of England. It is found in the Septaria clays of Northern 
and Central Germany, in the Miocene of the Vienna Basin (Baden and Nussdorf beds) 
and Lower Bavaria, in Pliocene clays near Sienna (Coroncina), at Turin, and Palermo, 
in the Crag of our Eastern Counties, and in other Tertiary deposits. 
It is equally common in the recent state. We have note of its occurrence off almost 
every portion of the shores of Europe, though never in very deep water. 
POLYMORPHINA GUTTA, D'Orbigny. (Pl XXXIX. figs. 3, a,b.) 
Polymorphium pyriformium, Soldani, 1789, Testac. ac Zoophytograph. vol. ii. p. 117, pl. 122. fig. gg. 
Polymorphina (Pyrulina) gutta, D'Orbigny, 1826, Ann. Sci. Nat. vol. vii. p. 267, no. 28, pl. 12. figs. 5, 6; 
Modèle no. 30. 
? P. (Globulina) clavata, Roemer, 1838, Neues Jahrb. für Min., Jahrg. 1838, p. 386, pl. 3. fig. 38. 
Pyrulina obtusa, Reuss, 1862, Sitzungsb. d. k. Akad. Wissensch. vol. xlvi. p. 79, pl. 9. fig. 9. 
Polymorphina gutta, Jones, Parker, and Brady, 1866, Monogr. Crag Foram. pl. 1. figs. 46, 47. 
Rostrolina, sp., Von Schlicht, 1869, Foram. Septar. Pietzpuhl, p. 72, nos. 408, 409, and 411, pl. 26. 
figs. 1-6, 10-12. 
Pyrulina, sp., id. ibid. nos. 423, 424, pl. 25. figs. 55, 56, pl. 27. figs. 13-15. 
Characters.—Shell ovate-elongate, symmetrical, pyriform ; anterior portion tapering, 
acuminate; posterior obtuse, rounded; margin entire, septal lines not depressed. 
fparmbers elongate, epee embracing, arranged triserially. Surface smooth. Length 
5 inch. 
sch explained in the introduction (vide ante, p. 209), the earlier writers were accus- 
tomed to divide the Polymorphine into several genera or subgenera, and the present 
species was made the type of one of the groups, under the name of Pyrulina gutta. As 
this subdivision of the genus is being gradually abandoned, even by those who have been 
its upholders, it is unnecessary to make further allusion to it. 
P. guita, in good specimens, presents tolerably definite characters, its triserial ar- 
. rangement, closely-embracing chambers, and circular transverse section being sufficient 
for ordinary diagnosis. Its long, tapering upper extremity and numerous chambers dis- 
tinguish it from P. gibba, and the rounded base and compact spiral build from its near 
ally P. acuminata. 
Pyrulina obtusa, Reuss, is more regularly elliptical than the generally accepted type, 
but may fairly be associated with it. The number of individuals that agree in every 
point with D'Orbigny's model is very limited, and we are obliged, as in every other 
group, to make some allowance for variation amongst the specimens associated under 
one specific name. 
