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versely on tlie septal face of the terminal segment, close to the margin of the previous 
convolution, nearly median ; adult shells have also a supplementary orifice, in the form 
of a vertical slit in the beak-like projection of the peripheral angle of the final 
segment. Walls coarsely perforated. Diameter, -^th inch (0‘84 mm.). 
This is an exceedingly interesting modification of the Planorbuline type. The test is 
nautiloid, and the later segments of adult shells are furnished with two apertures, one at 
the inner margin, close to the edge of the previous convolution, the other at the distal 
or peripheral angle ; so that in point of fact the species is isomorphous with both 
Nonionina and Cristellaria. The anomalous feature is the peripheral orifice ; and this, 
though invariably present in fully formed specimens, does not make its appearance during 
the earlier stages of growth, indeed it has not been traced with any certainty before the 
last four or five segments. A similar abnormal condition has been observed in 
Pulvinulina elegans. 
Truncatulina rostratci occurs on the northern shores of Papua, namely, in Humboldt 
Bay, 37 fathoms, and near the Admiralty Islands, 16 to 25 fathoms; and it has also 
been taken off Tongatabu, Friendly Islands, 18 fathoms. 
Truncatulina reticulata, Czjzek, sp. (PI. XCYI. figs. 5-8). 
Rotalina reticulata, Czjzek, 1818, Haidinger’s Naturw. Abkandl., vol. ii. p. 145, pi. xiii. 
figs. 7-9. 
Siplionina fimbriata, Reuss, 1849, Denkschr. d. k. Akad. Wiss. Wien, p. 372, pi. xlvii. fig. 6, a.b. 
„ puteolana, Costa, 1856, Atti dell’ Accad. Pontan., vol. vii. p. 27, fig. 22, A.JB.C. 
Planorbulina reticulata, Parker and Jones, 1865, Phil. Trans., vol. civ. p. 379. 
Siplionina fimbriata, Terrigi, 1880, Atti dell’ Accad. Pontif., ann. xxxiii. p. 212, pi. iv. fig. 69. 
In Truncatulina reticulata the Planorbuline lipped aperture presents an exaggerated 
development, generally taking the form of a short oval neck with everted edge ; and the 
segments are bordered to a greater or less degree with a tubulated fringe, which forms a 
conspicuous marginal keel. The carinal tubuli of small specimens (fig. 7 ) are relatively 
large, and impart an irregularly serrate aspect to the periphery ; in more fully grown 
examples (fig. 5) the marginal expansion presents a less broken outline ; whilst shells of 
still larger dimensions (fig. 8) are characterised by a wide continuous keel with comparatively 
indistinct tubulation. 
The species inhabits a somewhat wide geographical area. It has been noticed at 
various points in the Mediterranean, at depths of 100 to 360 fathoms; on the coast of 
Portugal, 50 fathoms ; in the West Indies, 390 to 450 fathoms ; and off Bermuda, 435 
fathoms ; off the coast of South America, near Pernambuco, 350 fathoms ; on the southern 
shores of Australia, 38 fathoms ; and at six Stations amongst the islands of the South 
Pacific, 17 to 410 fathoms. 
(ZOOL. CHALL. EXP. PART XXII. 1884.) 
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