412 
THE VOYAGE OF H.M.S. CHALLENGER. 
segments of the final pair are relatively large, and constitute the principal part of the 
whole visible shell. 
Pleurostomella rapa has been found in company with the species last described, in 
coral-sand dredged off the Ki Islands, at a depth of 129 fathoms. 
Prof. GiimbeTs fossil specimens were from the Eocene marl of the Gotzreuther Graben 
in the Bavarian Alps. 
Pleurostomella alternans, Schwager (PI. LI. figs. 22, 23). 
Pleurostomella alternans, Schwager, 1866, Novara-Exped., geol. Theil, vol. ii. p. 238, pi. vi. 
figs. 79, 80. 
„ eoccena, Giimbel, 1868, Abh. d. k. bayer. Ak. Wiss., II. CL, vol. x. p. 630, pi. i. 
fig. 53. 
„ „ Hantken, 1875, Mittheil. Jabrb. d. k. ung. geol. Anstalt, vol. iv. p. 44, 
pi. xiii. fig. 17. 
„ alternans, Terrigi, 1880, Atti dell’ Accad. Pont., ann. xxxiii. p. 199, pi. ii. fig. 46. 
,, obtusa, Berthelin, 1880, Mem. Soc. g4ol. France, ser. 3, voL i., Mem. V., p. 29, 
pi. L fig. 9. 
„ reussi, Id. Ibid. p. 28, pi. i. figs. 10-1 2. 
The specimens figured by Dr. Schwager under the name Pleurostomella alternans 
exhibit in their fullest development the typical features of the genus. I find no 
character in the Pleurostomella eoccena of Giimbel not provided for by this species ; and 
if the latitude as to minor particulars indicated by the original drawings be admitted, two 
of the specific names introduced by M. Berthelin are also needless. It is quite evident, 
from the variability of the recent specimens of Pleurostomella alternans, that an even 
wider morphological range than that suggested by Dr. Schwager may safely be included 
within its specific limits. 
In the living condition, Pleurostomella alternans has been obtained from near the 
Ki Islands, south-west of Papua, 129 fathoms ; and from' a single Station south of the 
Low Archipelago, 2075 fathoms. 
Under one name or other, the occurrence of fossil specimens has been recorded from 
the Cretaceous formation of France (Berthelin), from the early Tertiaries of the Bavarian 
Alps (Giimbel), from the middle Tertiaries of Hungary (Hantken), and from the later 
Tertiaries of the neighbourhood of Borne (Terrigi), and of the Nicobar Islands (Schwager). 
Pleurostomella subnodosa, Reuss (PL LII. figs. 12, 13). 
Nodosaria nodosa (pars), Reuss, 1845, Verstein. Bohm. Kreid., pt. 1, p. 28, pi. xiii. fig. 22 ( fide 
Reuss). 
Dentalina subnodosa { pars), Id. 1850, Haidinger’s Naturw. Abhandl., vol. iv. p. 24, pi. i. fig. 9 
( fide Reuss). 
Pleurostomella subnodosa, Id. 1860, Sitzungsb. d. k. Ak. Wiss. Wien, vol. xl. p. 204, pi. viii. fig. 
2, a.b. 
„ „ Marsson, 1878, Mittbeil. Naturw. Vereine Neu-Vorpom. u. Rugen, 
Jahrg. x. p. 133. 
