REPORT ON THE FORAMINIFERA. 
193 
The large thick-shelled Miliolce flattened on two sides in a direction at right angles 
o o o 
to the normal plane of compression have long been familiar to rhizopoclists under 
d’Orbigny’s name Biloculina contraria ; and the recent researches of Seguenza and 
Steinmann have led to the recognition of that species as the type of a new generic group. 
About the year 1868, a number of specimens of a form closely allied to Biloculina 
contraria were obtained by the late Edward Waller, from sands dredged in the Faroe 
Channel, during the “ Lightning ” Expedition. The specimens, which were tolerably 
abundant, differed from Biloculina contraria in their relatively thinner build, the 
frequent asymmetry of the two sides, and the tendency to assume a crosier-like rather 
than a lenticular shape. Some of these, kindly supplied by the Rev. A. M. Norman, 
from Mr. Waller’s collection, are represented in PI. CXIV. figs. 4-7. They were at 
first regarded as examples of a new species of Hauerina, and the name Hauerina 
ivalleri had been assigned to them in manuscript. Prof. Seguenza, however, in his 
recent memoir, Le Formazioni Terziarie nella Provincia di Reggio (Calabria), has 
described and figured fossil organisms identical with them in every important particular, 
under the generic appellation Planispirina. 
Very shortly after the appearance of Seguenza’s work, 1 a memoir was published by 
Dr. Steinmann of Strassburg, entitled Die Foraminiferengattung Nummoloculina, n. g., 
containing an elaborate exposition of the structure and affinities of the Biloculina 
contraria of d’Orbigny. The most important conclusion resulting from Steinmann’s 
researches was, that the planospiral habit of growth, the number of segments in the 
later convolutions, and above all the lateral extension of the chamber-walls with the 
consequent Nummuline lamination of the shell, were distinctive characters of sufficient 
importance to serve as the basis of a new generic group. 
Simultaneously with this paper appeared one by myself, in which similar forms, 
found in the “Porcupine” dredgings, amongst them those figured in PI. XI. figs. 10, 11, 
were described as examples of a new species of Hauerina. 
There seems on the whole some advantage in the course followed by Seguenza and 
Steinmann ; and, notwithstanding the close relationship of such shells to Hauerina on 
the one hand, and Biloculina on the other, it may be convenient to accept the two 
species referred to as the representatives of an independent genus, under the earlier 
name Planispirina. Aberrant forms like Biloculina irregularis , cl’Orbigny, Biloculina 
1 As the question of the relative priority of the terms Planispirina ancl Nummoloculina is involved, it may be 
stated that Prof. Seguenza’s memoir bears on the title-page the date 1879, and that it was in the hands of the Secretary 
of the R. Accad. dei Lincei in February 1877. Dr. Steinmann’s paper appeared in the N ernes Jahrb.fiir Min., &c., for 
1881, but the separate copies were printed and distributed at the latter end of 1880. I may be allowed to add that 
PL XI. of the present Report was drawn on the stone by Mr. Hollick as long ago as 1878, and that the resemblance of 
the figures of this species to some of those given by Steinmann is in a certain sense accidental. 
As a matter of choice the term Nummoloculina seems more appropriate than Planispirina to a genus comprising 
amongst others such forms as Planispirina sigmoidea , but the selection in such a case is governed by the ordinary rule 
of precedence. 
