EORAMINIEERA FROM THE NORTH ATLANTIC AND ARCTIC OCEANS. 355 
the neck is protruded in some cases to a considerable extent, and has about three 
secondary tubular apertures arising from it laterally, and almost at right angles to the 
main tube. This is an isomorphism with Polymorpliina tubulosa, and with certain feeble 
bifurcating forms of Nodosaria from Cretaceous beds. 
Plate XVI. figs. 11 a, 11 b (North Atlantic). 
The specimen here figured is a little less globular than figs. 40, 41 of Plate XIII., 
and has its reticulation rather more regular. Rare and middle-sized at 1450 fathoms, 
lat. 50° 6', long. 45° 45', North Atlantic. In Dr. Wallich’s ‘ North- Atlantic Sea-bed,” 
pi. 5. fig. 21 seems to be L. squamosa. 
Fig. 11 a, Plate XVI. has the six-sided meshes one above the other, touching by the 
parallel sides of the hexagon, and in so much corresponding with Williamson’s L. sca- 
lariformis (Monogr. p. 13. pi. 1. fig. 30), and Reuss’s L. geometrica (Monogr. Lag. p. 334, 
pi. 5. fig. 74) ; but this straight meridional arrangement of the meshes is lost in the less 
regular reticulation of such specimens as figs. 40 & 41 in Plate XIII., where square, 
six-sided, and irregular meshes occur, in straight, oblique, and irregular lines. Professor 
Reuss’s unnecessary disuse of Montagu’s term squamosa for this varietal group leads to 
increased confusion in any attempt to subdivide these reticulate Lagence , which have no 
natural divisions among themselves. 
Lagena sulcata , Walker and Jacob, Var. ( JEntosolenia ) marginata, Montagu. Plate XIII. 
figs. 42-44 (Arctic); Plate XVI. figs. 12 a, 12 b (North Atlantic). 
These are flattened forms variable in shape ; generally Entosolenian, but sometimes 
Ectosolenian with a long delicate neck. This compressed shape is usually associated with 
a trenchant margin, sometimes slightly apiculated (as in fig. 42), and sometimes dentate 
or rowelled (as in Williamson’s Monograph, pi. 1, figs. 21 a , 25, 26), reminding one of 
the keel of certain Cristellarice. Occasionally in large well-developed specimens of L. 
marginata (recent and fossil) the margin is composed of a large predominant rib, 
strengthened by a pair of smaller costae ; showing that, as in other Foraminifera, espe- 
cially the Nodosarine group, the exogenous costae gather themselves to the margins, the 
rest of the surface becoming less and less ornamented. The pseudopodial pores also 
usually affect the neighbourhood of the thickened margin in these flattened forms, just 
as they follow the ridges of L. striatopunctata (figs. 25-27). Occasionally the pseudo- 
podia have perforated the whole surface, either sparsely, as in fig. 42 a, or freely, as we 
have seen in specimens from the Indian Sea. 
In some rare specimens from the Coral-reefs of Australia, and fossil at Bordeaux, we 
see the pseudopodia begin to enter the shell-wall near the centre, and then burrow 
radially to escape near the margin; the shell-surface being perfectly smooth and as 
polished as glass. This is our subvariety Lagena radiato-marginata, Plate XVIII. fig. 3. 
In the Crag of Suffolk there is another subvariety of L. marginata , in which the radiating 
canals are visible only at the margin. 
The intussuscepted neck-tube in L. marginata is generally more or less oblique, some- 
