"REPORT ON THE FORAMINIFERA. 
711 
that is to say, not marked with longitudinal furrows ; they are either curved or straight, 
and are pointed at their extremities. The septa are double, and in large specimens the 
sutures are marked externally either by limbate lines or by rows of exogenous beads. 
The body of the test seldom measures more than ^th inch (0'5 mm.) in diameter. 
The present species must not be confounded with the Rotalia pulchella of d’Orbigny 
(Ann. Sci. Nat., vol. vii. p. 274, No. 32 ; — Modele, No. 71), which, according to modern 
nomenclature, belongs to the genus Pulvinulina. 
The Challenger collections furnish doubtful specimens of Rotalia pulchella from 
Kandavu, 255 fathoms; and Humboldt Bay, Papua, 37 fathoms. Better examples have 
been obtained from the Strait of Banca, 7 or 8 fathoms (Parker) ; off Java (Robertson) ; 
and off Penang (Siddall). The originally published habitat was the coast of Cuba. 
Calcarina, d’Orbigny. 
Nautilus, pars, Gmelin [1788], Fichtel and Moll, Dillwyn. 
Siderolites, Lamarck [1801], Montfort, Blainville. 
Siderolina, Blainville [1825], d’Orbigny (?). 
Calcarina, d’Orbigny [1826], Bronn, Reuss, Carpenter, Parker and Jones, Morris and Quekett, 
Scbwager, Giimbel, Brady, Carter, &c. 
The structural relatious of the genus Calcarina have been worked out with much 
care by Dr. Carpenter ; and his account of the minute anatomy of the testaceous skeleton, 
first published in the Philosophical Transactions for 1860 (p. 548), and subsequently in 
the Introduction to the Study of the Foraminifera (p. 216), leaves no point of importance 
unnoticed. 
In general terms, the typical form of the test of Calcarina is that of an irregular 
biconvex disk with radiating peripheral spines. These characters it shares to a greater 
or less extent with Tinoporus and with certain varieties of Rotalia. From Tinoporus 
the difference is primarily one of internal structure ; but the two types are also 
distinguishable by external features, the later chambers of the Rotaliform spire of 
Calcarina, for example, being apparent on the inferior side of the disk, whilst in Tinoporus 
no portion of the spire is visible. 
The affinity of Calcarina with Rotalia is of a much closer description, indeed it has 
been said with perfect justice that the characters which differentiate the two genera are 
altogether gradational. The most serviceable distinctions are, — firstly, the aperture, 
which in the typical Calcarina consists of a row of pores along the inner margin of the 
septal face ; and secondly, the extraordinary development of the supplemental skeleton 
and the canal system. It is true that analogous structures are occasionally met with 
amongst the higher Rotalice, but they differ from those of Calcarina both in nature and 
extent, and the exceptional specimens in which they form a conspicuous feature are not 
such as resemble the latter genus in external contour. 
