680 
THE VOYAGE OF H.M.S. CHALLENGER. 
Rupertia, Wallich. 
Rupertia, Wallich [1877], Biitschli, Brady, Schlumberger. 
The genus Rupertia was established by Wallich for a number of Planorbuline 
Foraminifera obtained by him from near the coast of Greenland, during the cruise of 
the “Bulldog” in 1860. The morphological characters of the type, as well as the 
particulars of its geographical distribution, will be most easily discussed in connection 
with its single specific form. 
Rupertia stabilis, Wallich (PI. XCVIII. figs. 1-12). 
Rupertia stabilis, Wallich, 1877, Aim. and Mag. Nat. Hist., ser. 4, vol. xix. p. 501, pi. xx. 
„ „ Schlumberger, 1883, Feuille des Jeunes Naturalistes, ann. xiii. p. 27, pi. ii. 
figs. 6—8. 
This interesting organism forms the subject of a short paper by Dr. Wallich, 1 
which contains, in addition to the author’s account of the species, a note by Profs. 
Rupert Jones and Parker on its structure and affinities. The specimens on which the 
descriptions are based appear from the drawings to have been somewhat obscure, and 
their structural features not so well marked externally as those of many which have 
since been obtained ; nevertheless the essential characters of the species are correctly 
stated, and the points left for further elucidation are comparatively few, and only such 
as can now be satisfactorily cleared up. It has recently been well figured by 
Schlumberger {loo. cit.). 
In its typical presentment the test of Rupertia stabilis has the form of a straight, 
curved, or inequilateral column, with a slightly expanded discoidal base and a swollen 
head. The length of the columnar portion, and the shape and relative size of the 
capitulum vary in .every specimen. The external contour of many of the shells is 
aptly suggested by the terms “ an irregular lumpy outline, like some of the asymmetrical 
Puff-balls, and somewhat resembling an inverted Ascidia mamillata ” (Wallich, op. cit., 
p. 502), whilst that of others is more regular and more distinctly spiral. 
During the early stages of growth the shell is very similar in form and habit to an 
ordinary adherent Rotalian such as Truncatulina refulgens, as may be seen from the 
young specimen represented in fig. 1. The base, however, attains its full width upon 
the completion of a single convolution, and the later coils are superimposed vertically, 
each only slightly embracing its predecessor. After the second convolution the diameter 
begins to increase ; in some cases the third widens suddenly and forms a bulbous end to 
the shell, in others the increase is more gradual. The adult test may have as many as 
five convolutions, but more commonly the number is less. 
The adherent base forms a slightly expanded flat or concave disk, on which, under 
1 On Rupertia stabilis, a new sessile Foraminifer from the North Atlantic, loc. cit. 
