EEPOET ON THE FOEAMINIFEEA. 
547 
South Pacific, at depths of less than 500 fathoms; but this is probably only a small 
portion of the area it inhabits. 
A similar remark might be made with reference to its geological distribution. 
Under one name or other, the present variety has been recorded from microzoic rocks of 
almost every age as far back as the Cretaceous period. 
Cristellaria articulata, Eeuss (PL LXIX. figs. 10-12 ; wild-growing forms, figs. 1-4). 
Robulina articulata, Eeuss, 1863, Sitzungsb. d. k. Akad. Wiss. Wien, vol. xlviii. p. 53, pi. v. fig. 62, 
Cristellaria articulata, Id., 1870, Ibid. vol. lxii. p. 483. — Schlicht, 
1870, Foram. Pietzpuhl, pi. xvii. figs. 5-12. 
This is a thick variety of Cristellaria rotulata, with somewhat flattened sides and 
obtusely angular or rounded peripheral edge. The segments are relatively large, and 
seldom number more than six or seven in the final convolution. In some specimens the 
later chambers only partially enclose those of the previous convolution, and the test shows 
a tendency to become evolute. There is frequently considerable deposit of clear shell, 
substance, especially in the umbilical region. 
Fine examples of Cristellaria articulata occur in the dredged sands from off Culebra 
Island, 390 fathoms; and off Nightingale Island, Tristan da Cunha, 100 to 150 fathoms- 
In the latter locality the species is very abundant, and what is more remarkable, a large pro- 
portion of the shells assume anomalous wild-growing forms, such as are represented in 
figs. 1-4. Strikingly different as they appear, the relationship between these and the 
more regular and typical specimens is very evident when a large number are seen together. 
The fossil examples of the species figured by v. Reuss and v. Schlicht were from the 
Septaria-clays of Offenbach and Pietzpuhl in Germany. 
Cristellaria rotulata, Lamarck, sp. (PL LXIX. fig. 13, a.b.). 
“Cornu Hammonis seu Nautili,” Plancus, 1739, Conch. Min., p. 13, pi. i. fig. III. 
Lenticulites rotulata, Lamarck, 1804, Annales du Mus4um, vol. v. p. 188, No. 3. — Tableau 
Encycl. et Meth., pi. cccclxvi. fig. 5. 
Robulina muensteri, Koemer, 1841, Yerstein. norddeutsch. Kreid., pt. 2, p. 98, pi. xv. fig. 30. 
,, simplex, d’Orbigny, 1846, Eor. Foss. Vien., p. 102, pi. iv. figs. 27, 28. 
„ stellifera, Czjzek, 1847, Haidinger’s Naturw. Abhandl., vol. ii. p. 142, pi. xii. figs. 26, 27. 
„ trigonostoma, Eeuss, 1851, Zeitschr. d. deutscli. geol. Gesellsch., vol. iii. p. 69, pi. iv. 
fig. 26. 
,, neglecta, 
Id. 
Ibid. 
p. 69, pi. iv. fig. 27. 
„ deformis, pars, Bornemann, 1855, 
Ibid. 
vol. vii. p.337, pi. xiv. fig. 
„ depauperata, 
Id. 
Ibid. 
p. 337, pi. xiv. fig. 11. 
„ incompta, (1) 
Id. 
Ibid. 
p. 336, pi. xiv. fig. 12. 
Cristellaria calcar (typica), Williamson, 1858, Eec. For. Gt. Br., p. 27, pi. ii. figs. 52, 53. 
,, rotulata, Parker and Jones, 1865, Phil. Trans., vol civ. p. 345, pi. xiii. fig. 19. 
„ inornata, Terquem, 1876, Anim. sur la Plage de Dunkerque, p. 70, pi. vii. fig. 18 
„ austriaca, Id. Ibid. p. 70, pi. vii. fig. 20 , a.b. 
