FORAMINIFERA FROM THE NORTH ATLANTIC AND ARCTIC OCEANS. 
388 
Planorbulina farcta, Fichtel and Moll, sp., Yar. Mediterranensis , D’Orbigny. Plate XVI. 
fig. 21 (North Atlantic). 
This explanate Planorbulina is of small size in the North Atlantic, as usual in North 
Temperate seas; it is rare off the Irish coast at 43 fathoms. 
It is spiral at first, then excentric, and ultimately concentric ; always orderly in its 
growth, with bipolar chambers ; not having exogenous matter, nor a free growth of 
marginal apertures. It flourishes in the warmer temperate seas ; is starved in the 
British area ; abounds in the Mediterranean and Australian seas ; but in the latter is 
less plentiful than PI. vulgaris , with which it is associated. It forms a tiny scale on 
flat-fronded sea-weeds, and has a livid pinkish colour, both from its contained sarcode 
and from the shell-substance being actually coloured. 
Planorbulina farcta, Fichtel and Moll, sp., Var. ( Anomalina ) coronata, Parker and Jones. 
Plate XIV. figs. 7-11 (Arctic). 
This has been termed Anomalina coronata , Ann. Nat. Hist. 2 ser. vol. xix. p. 294 ; but 
it belongs to Planorbulina , and the term Anomalina is not really wanted, however con- 
venient it may be as a term for the subsymmetrical or somewhat biconvex arrested 
Planorbulince , as Truncatulma indicates the plano-convex few-chambered forms. To 
make the so-called genus Anomalina , D’Orbigny took several of the minor forms of Pla- 
norbulina farcta, namely those which are somewhat symmetrical and subnautiloid, with 
one variety of Discorbina Turbo (A. elegans, Modele, 42). 
On taking into consideration the evident passage of form from the plano-convex 
(Truncatuline) to the biconcave (Anomaline) condition of the shell, shown by figs. 8, 
10, 9, 7, & 11, the observer may at once see the force of the above remarks. 
This variety, PI. coronata , has the same kind of shell-substance, thick, subtransparent, 
and coarsely perforated, as PI. lobatula ; it has a greater tendency to develope clear, 
non-perforate, exogenous shell-matter on both faces of the shell, sometimes hiding the 
septal lines ; the pseudopodia chiefly passing from the periphery of the chambers and 
through the lacunae in the superadded coating, both on the umbilical (fig. 10) and the 
flatter spiral surface (fig. 8). The presence of these lacunae is highly interesting, as 
being the first rough outline of the great vascular or interseptal canal-system which 
attains such perfection in the highly developed Botalince , Polystomellce, and Nummulina?. 
PI. coronata is not so common as PI. lobatula ; it abounds, however, in MacAndrew 
and Barrett’s Norway dredgings (at five places) ; and it is abundant at certain places 
in the Mediterranean, especially at about 100 fathoms. At such depths it is that 
PI. coronata takes the place of PI. lobatula , by living independently and developing its 
surfaces more or less freely, whilst but few of the parasitical variety are left on the rare 
shells of deep water. PI. coronata has been found abundantly in the North British 
seas by Mr. H. B. Brady. 
PI. vulgaris also has a subnautiloid form in its young state; and throughout its 
growth the chambers are more or less convex both on the attached and the free face. 
3 f 2 
