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THE VOYAGE OF H.M.S. CHALLENGER. 
Ophthalmidium, Kiibler. 
Oculina, Kiibler and Zvvingli [1866]. 
Ophthalmidium, Kiibler [1870], 
Hauerina, pars, Brady [1879]. 
Under the generic name Oculina , 1 subsequently changed by Kiibler to Ophthalmidium , 2 
because the former term was already employed by naturalists for another and very 
different group of organisms, Kiibler and Zwingli have described a number of anomalous 
Miliolce, obtained by them from various beds of Liassic and Oolitic age in Switzerland 
and elsewhere. 
There can be little doubt that several of the specimens figured by these authors are 
simply Spiroloculince with that irregularity of contour which is a not uncommon feature 
of the early representatives of the genus, and they are very similar in general character 
to the species named by Terquem and Berthelin Spiroloculina concentrica, the 
multiform conditions of which are illustrated by a large series of drawings in their 
memoir on the Foraminifera of the Middle Lias of Essey-les-Nancy . 3 
But amongst Kiibler and Zwingli’s specimens there are some, that for example 
described and figured as Ophthalmidium liasicum, in which there is a distinct deviation 
from the Spiroloculine plan of growth, the commencement of the shell being planospiral and 
non-septate (Cornuspiral), and these may very properly be taken as the type of an inter- 
mediate group. If we accept the dimorphous, or occasionally trimorphous condition of 
the test as the essential character, the minor structural features laid down by Kiibler need 
not be insisted upon. The supposed perforation of the shell-wall which he describes as 
of frequent occurrence has been adverted to both by Bupert Jones and by Terquem and 
Berthelin, and I agree with these authors in regarding the statement as probably 
erroneous, and dependent on an imperfect method of observation. Many of the specimens 
are punctate, that is to say, studded with superficial pits or depressions, and when 
mounted in Canada balsam or turpentine, and examined by transmitted light, could only 
be distinguished with difficulty from perforated shells. 
Without necessarily accepting all Kiibler and Zwingli’s species as belonging to the 
genu's, I propose to adopt the term Ophthalmidium for the complanate Miliolidce which 
commence growth on the Cornuspiral plan and become Spiroloculine at a subsequent stage, 
in some cases making a further change by putting on three or four segments in each of 
the latter convolutions. 
The recent specimens answering to this general description may be referred to two 
varietal forms, in one of which the chambers are inflated and the peripheral margin 
1 Mikroskopische Bilder aus der Urwelt der Schweiz. Heft ii. der mikroskopischen Mittheilungen. 
Neujahrsblatt von der Biirgerbibliothek in Winterthur, 1866 ; p. 11, pi. i. fig. 24, &c. 
2 Die Foraminiferen des schweizerischen Jura, Winterthur, 1870, p. 46. 
3 MFm. Soc. giol. France, 1875, ser. 2, vol. x. mem. III., pi. xvii. figs. 1-4. 
