512 
Transactions of the Society. 
the Milioline plan as in A. nitida d’Orbigny, whilst in the other the 
initial portion consists of a spherical primordial with circumambient 
chamber as in the genus Orbitolites. Speaking of Vertebralina conico- 
articulata , Goes remarks/ “ Its most singular form is that in which 
the primordial chamber is flask-formed, and the subsequent chamber 
develops itself from the top of its neck and so on, one chamber 
after the other in Nodosarina fashion ; thus its usual Miliolina formed 
stage is' passed over altogether.” All the Malay specimens are of 
this form, and are extremely attenuated. It will be noticed that the 
Nubecularict tibia (pi. v. fig. 3) has the initial chambers of this 
character, and it becomes a question if this species should not be 
removed to the genus Articulina. Jones and Parker remark/ “ From 
the Clam-shells of the East Indian Seas, and from the Strombus 
gigas of the West Indies, we get minute rectilinear individuals of 
Nubecularia, with a spiral commencement (2V. tibia var. nov.).” And 
again (p. 456), “ Of the straight specimens (2V. tibia) we have only 
fragments, the spiral portion being absent.” Brady also writes/ 
“ Owing perhaps to the thinness of the walls and the slenderness 
of the stoloniferous tubes, specimens are scarcely ever found with 
more than three segments.” A glance at the published figures of 
N. tibia will suggest that nearly all of them represent imperfect 
examples, and it might reasonably be assumed that the earlier 
chambers were of the same character as those of the Malay speci- 
mens. In these latter the shell substance of N. tibia is dense 
and opaque, whilst that of A. conico-articulata is thin and somewhat 
translucent. It must be left to subsequent researches to prove 
whether N. tibia is a distinct species, or if it is only a smooth form 
of A. conico-articulata. 
As for the latter, it may be convenient to assume that Batsch’s 
species, as indeed the contour of the figure suggests, had the initial 
chambers of the Orbitolites- form, whilst d’Orbigny’s A. nitida with the 
Milioline commencement may be treated as a distinct species. 
Acting on this assumption, it may be stated that A. nitida is not 
represented in the gatherings by Goes from the Caribbean Sea, nor 
in Mr. Durrand’s anchor mud; that, allowing for errors of inter- 
pretation, they both occur in the ‘ Challenger ’ and Abrolhos Bank 
collections ; and that, supposing Egger’s A. extensa to be equal to 
A. conico-articulata , they are both represented in the ‘Gazelle’ 
soundings. 
For A. conico-articulata Egger’s Stations are Mauritius and 
West Australia, and for A. extensa (which he considers a variety of 
A. funalis ) Mauritius only. 
In the Malay Archipelago the Orbitolites- form is very abundant, 
and occurs at nearly all the Stations in both areas. 
* K. Svenska Vet.-Akad. Handl., vol. xix. 1882, p. 121. 
t Quart. Journ. Geol. Soc., vol. xvi. 1860, p. 455. 
% ‘ Challenger ’ Report, p. 135. 
