184 
THE VOYAGE OF H.M.S. CH ALLEY GEE . 
The broad, flat contour of Articulina lineata, its unconstricted margin, and neatly 
fitted segments, are well-marked characters, sufficient to distinguish it from aEy of 
its congeners. 
It is a rare species, to judge by the small number of specimens hitherto found, 
and somewhat limited in bathymetrical range. It has been noticed at four Chal- 
lenger Stations, namely : — olf Kandavu, Fiji Islands, 210 fathoms and 255 fathoms ; 
off Raine Island, Torres Strait, 155 fathoms ; and in company with other varieties of the 
same type, off the Bermudas, 435 fathoms. 
Articulina sagra, d’Orbigny (PI. XII. figs. 22-24). 
Articulina sagra, d’Orbigny, 1839, Eoram. Cuba, p. 160, pi. ix. figs. 23-26. 
Vertebralina cassis, Id. Ibid. p. 72, pi. vii. figs. 14, 15. 
„ mucronata. Id. Ibid. p. 72, pi. vii. figs. 16-19. 
„ „ Id. 1846, For. Foss. Vien., p. 120, pi. xxi. figs. 18, 19. 
A comparison of a large number of specimens from various localities has led to the 
conclusion that the three d’Orbignian species above enumerated are only individual 
modifications of the same form, and that although the Milioline chambers sometimes 
show a tendency to open out and in so far to approach the characters of Vertebralina, 
the central or typical condition is nearly that portrayed in d’Orbigny’s figure of 
Articulina sagra,. It is impossible to examine side by side the drawings of Verte- 
bralina mucronata in the “Cuba” or the “Vienna Basin ” monograph, and those given in 
PI. XII. figs. 22-24 of the present Report, without arriving at the conviction that 
notwithstanding the less strictly Milioline arrangement of the early segments in the 
cl’Orbignian figures, the whole series must be referred to a single species. It appears 
equally clear that the drawing of Vertebralina cassis ( loc . cit.) represents an immature or 
arrested specimen not specifically distinct from the rest. 
The Milioline characters of the early chambers are readily made out in most of the 
specimens that have come under my notice ; nevertheless, judging from d’Orbigny’s 
figures, this portion of the shell is liable to a certain amount of variation or even of 
obscurity in the mode of segmentation, but the species is easily recognised in its mature 
state by the form of the linear segments and by the aperture. 
Articulina sagra is found chiefly in coral-sands, and sometimes at considerable depths. 
The Challenger gatherings furnish specimens from the Honolulu Reefs, 40 fathoms ; from 
the Friendly Islands, off Tongatabu, 18 fathoms ; off Kandavu, Fiji Islands, 255 fathoms ; 
from near Sombrero Island, West Indies, 450 fathoms; and from the Bermudas, 435 
fathoms. D’Orbigny records its occurrence in littoral sands from several of the West 
Indian Islands 
