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THE VOYAGE OF H.M.S. CHALLENGER,. 
catulina and Anomalina, which are only conceived as subordinate divisions of a single 
group, is therefore completely justified .” 1 
It is impossible from these definitions to draw any accurate idea as to what forms 
should be included in the sub-genus ; nevertheless, from the figures of the various species 
that have been described, a series may be selected of which Anomalina rotula, d’Orb. 
(For. Foss. Yien., p. 172, pi. x. figs. 10-12) represents the extreme modification in one 
direction, and Anomalina coronata, P. and J., that in the other;. the distinctive features 
of which are the nearly equilateral development of the test, and the more or less evolute 
character of both faces of the spire. In shape the forms referred to are either somewhat 
biconvex, nearly flat, or more or less biconcave ; and in point of habit the shell is never 
adherent. It appears better that the term Anomalina should be restricted to the sub- 
symmetrical, partially evolute varieties, leaving to Truncatulina all those which are 
involute on either one or both sides. The most important additions to the series that 
this arrangement entails are Planorbulina ammonoides, a near approach to which is found 
in d’Orbigny’s Anomalina austriaca, and Planulina ariminensis, which exemplifies the 
complanate modification of the same typical structure. 
Anomalina ammonoides, Eeuss, sp. (PI. XCIV. figs. 2, 3). 
Eosalina ammonoides, Reuss, 1845, Verstein. bohm. Kreid., pt. 1, p. 36, pi. xiii. fig. 66; pi. viii. 
fig. 53. 
„ „ Id. 1850, Haidinger’s Naturw. Abhandl., vol. iv. p. 36, pi. iv. fig. 2. 
Nonionina bathyomphala, Id. 1862, Sitzungsb. d. k. Ak. Wiss. Wien, vol. xlvi. p. 95, pi. xiii. 
fig. 1 , a.b. 
Eosalina weinkauffi, Id. 1863, Ibid. vol. xlviii. p. 68, pi. viii. fig. 97. 
„ maorica, Stache, 1864, Novara. -Exped., geol. Theil, vol. i. p. 282, pi. xxiv. fig. 32. 
„ orbiculus, Id. Ibid. p. 285, pi. xxiv. fig. 34. 
Planorbulina ammonoides, Parker and Jones, 1865, Phil. Trans., vol. civ. p. 379. 
Discorbina ammonoides, Reuss, 1865, Sitzungsb. d. k. Ak. Wiss. Wien, vol. lii. p. 456, No. 5. 
Eotalia capitata, Giimbel, 1868, Abhandl. d. k. bayer. Akad. Wiss., II. Cl., vol. x. p. 653, pi. ii. 
fig. 92. 
Eotalia ammonoides, Id., 1870, Sitzungsb. d. k. bayer. Akad. Wiss., p. 283. 
Planorbulina ( Anomalina ) ammonoides, Jones and Parker, 1872, Quart. Journ. Geol. Soc., 
vol. xxviii. p. 106 ; table, p. 109. 
„ ammonoides, Reuss, 1874, Das Elbthalgebirge in Sachsen, 2 ter Theil, p. 114, 
pi. xxiii. fig. 9. 
The nautiloid aspect of the test is perhaps a more constant and more noticeable 
feature of Anomalina ammonoides than of any other member of the group. The shell is 
generally much compressed, and nearly equally convex on the two sides ; the peripheral 
edge is round, and the aperture is placed almost symmetrically in the median line. In 
certain characters, however, the species betrays a tendency to variation. Some specimens 
1 Das Elbthalgebirge in Sachsen, 1874, 2'" Theil, p. 113. 
