REPORT ON THE FORAMINIFERA. 
189 
rounded, whilst in the other the chambers are more or less kept apart by thin shelly 
plates, and the margin is carinate. 
Ophthalmidium inconstans, H. B. Brady (PL XII. figs. 5, 7, 8). 
Hauerina inconstans, Brady, 1879, Quart. Journ. Micr. Sci., vol. xix., N. S., p. 54. 
Test complanate, thin ; commencing growth as a planospiral non-septate tube en- 
circling a somewhat inflated primordial chamber. At a later stage the spiral becomes 
segmented by constrictions at two opposite points in each convolution, and the chambers 
assume a Spiroloculine arrangement ; and in large specimens the latest convolutions 
often consist of three or (more commonly) four arcuate or sigmoid chambers. Segments 
furnished with a broad peripheral wing, which serves to separate the successive convolu- 
tions to a greater or less degree. Diameter of large examples, -^th inch (1*6 mm.). 
Specimens of Ophthalmidium inconstans in their fullest development partake more or 
less of the characters of Cornuspira, Spirolocidina .and Hauerina; and in the absence of 
sufficient material to serve as the basis of a new generic group, the form was treated in a 
previous paper as an aberrant species of the last-named genus. A considerable number 
of specimens, however, have since been collected, and the identity of their general struc- 
ture with some of the Mesozoic fossils, described by Kfibler under the generic term 
Ophthalmidium , has been satisfactorily made out. 
It is only rarely that large winged specimens, such as that represented in fig. 5, are 
met with, and all that have been found hitherto are a good deal broken at the edges ; 
but small shells, with the more regular contour of figs. 7,8, measuring about g^th inch 
(0'5 mm.) in diameter, are not uncommon. 
The distribution of the species appears to be world- wide. I have record of its 
occurrence at upwards of twenty Stations, scattered over the North and South Atlantic, 
the Southern Ocean, and the North and South Pacific. The depths vary from about 
100 to 2300 fathoms, but they are mostly between 350 and 1000 fathoms. The number 
of specimens found in any single locality is never very large. 
Ophthalmidium tumididum, n. sp. (PI. XII. fig. 6). 
Test complanate, commencing growth as a rounded tube coiled upon a somewhat 
inflated primordial chamber in a planospiral manner ; the earlier convolutions non- 
septate and Cornuspira-\ike, the subsequent ones constricted at intervals and eventually 
more or less regularly Spiroloculine ; peripheral edge rounded. Aperture arched or 
rounded, formed of the slightly constricted end of the tube. Longer diameter, 3 ] ^-th inch 
(0‘8 mm.). 
(ZOOL. CHALL. EXP. PART XXII. 1883.) 
Y 25 
