REPORT ON THE FORA MINIFERA. 
191 
Tertiary beds of the neighbourhood of Vienna, somewhat thinner also, and with scarcely so 
many segments in the outermost convolution. But these are variable characters, in which 
considerable latitude may properly be allowed. Recent specimens are occasionally as much 
as 1 ’0 mm. in diameter, and seldom have more than three chambers in the final whorl, 
whilst those from the Miocene are stated to be about one-third smaller, and have usually 
four peripheral segments. 
So far as can be gathered from the Challenger material, the present distribution of 
Hauerina compressa is restricted to a very small area. It occurs in two dredgings in the 
narrow sea between the northernmost part of Australia and the island of New Guinea, 
namely, off Booby Island, 6 to 8 fathoms, and off Raine Island, 155 fathoms, and a few 
small and doubtful specimens have been found in an adjoining locality ; but beyond 
these limits it has not been observed. Some years ago the species was included in a list 
of Foraminifera obtained from Dr. Gwyn Jeffreys’ Hebrides dredgings, 1 but these specimens 
must now be referred to the genus Planispirina. 
Of its geological history nothing is known beyond its occurrence at one or two points 
in the Miocene of the Vienna Basin. 
Hauerina circinata, H. B. Brady (PL XI. figs. 14-16). 
Hauerina circinata, Brady, 1881, Quart. Journ. Micr. Sci., vol. xxi., N. S., p. 47. 
Test nautiloid, thin, complanate ; composed of two or three convolutions, the last of 
which, consisting of six or seven segments, completely encloses those previously formed, 
segments arched, thin and rounded at their peripheral margins ; sutural lines marked by 
external constrictions. Colour milky white, sufficiently translucent to show the outline 
of the inner whorl of chambers. Aperture consisting of a number of perforations distri- 
buted irregularly over the septal face of the terminal segment. Diameter, ^gth inch 
(1 mm.). 
Hauerina circinata i is distinguished from the typical Hauerina compressa, not only 
by its more regularly nautiloid form and the larger number of chambers in each circuit, 
but by its embracing segments and thin diaphanous shell. The almost complete invest- 
ment of each convolution by the succeeding one, and the jDresence at the same time of 
the true Hauerine aperture, mark the species as a. connecting link between Hauerina, 
and Planispirina. 
In distribution Hauerina circinata appears to be limited to the same narrow area as 
the typical form. It has only been found in four shallow-water dredgings, amongst the 
islands lying between Australia and Papua, namely, — off Booby Island, 6 to 8 fathoms ; 
off Wednesday Island, 8 fathoms ; Flinders Passage, 7 fathoms ; and Torres Strait, 3 to 1 1 
fathoms. 
i Report Brit. Assoc., Nottingham Meeting, 1866, Trans. Sections, p. 69, 
