FORAMINIFERA FROM THE NORTH ATLANTIC AND ARCTIC OCEANS. 347 
varying strength ; either regularly, so as to form rectangular meshes (L. squamosa , var. 
catenulata, Williamson, and L. Melo , D’Orbigny; or less regularly, and forming — 
1st, either tetragonal or hexagonal network, with the meshes one above the other from 
the base to the top of the shell, and divided by nearly straight longitudinal ridges or 
walls; 2ndly, hexagonal network, with the meshes alternately placed (honeycomb- 
pattern), the walls being zigzag, and equally developed along and across ( L . squamosa , 
var. Jiexagona , Williamson). Lastly, hexagonal and quadrangular meshes are combined 
on one shell, as in L. squamosa , Montagu, sp., which herein well serves as the subtype. 
The “ asperse” of Reuss are such as are ornamented with granules and spines. These 
exogenous shell-growths are, without doubt, equivalent to linear and reticulate ridges, 
variously modified; just as hispid Nodosarince show gradual modifications of riblets and 
spines. As with the “ costatse” and the “ reticulatse,” no particular shape of shell speci- 
ally afiects this style of ornament. Reuss’s “compressse” comprise the more or less 
flattened Lagence , and must include those which he separates under the name Fissurina 
on the supposition that they are distinguishable by their slit-like aperture. All 
Lagence that are more or less compressed have the aperture correspondingly narrowed 
and outdrawn, just as all Nodosarice becoming flattened and “Linguline” have a more 
and more chink-like aperture. The transitions are extremely gradual both into “Fis- 
surina” and “ Lingulina” respectively, and are associated indiscriminately with all the 
other modifications of outline and ornament that belong to the species. The com- 
pressed Lagence usually take on one or more keel-like riblets at or near the margin, 
representing the local accumulation of the linear exogenous shell-growth so common in 
Lagena. A similar feature occurs in the Nodosarince, where a similar ornamentation 
obtains. 
Lastly, we propose to complete this artificial classification of the Lagence , by dividing 
oif those that, passing from a pointed or apiculate shape at the base, ultimately present 
a perforate or distomatous, continuously tubular shell, more or less fusiform. Keuss’s 
L. ctpiculata represents the smooth apiculate forms; D’Orbignt’s L. ccmdata the ribbed 
ones; our L.polita the smooth, and our A. distoma the costulate, perforate forms. (See 
Scheme of the Lagence , p. 348.) 
Of Lagena it may be said, that, though apparently one of the simplest of Foramini- 
fera, it is not one of the oldest, as far as our knowledge serves us at present. Nor can 
it be regarded as an arrested Nodosaria;. rather, it may be looked on as a higher 
specialization of the simple repetitive Nodosarian form. It has its isomorphisms, with 
Nodosaria , both in ornamentation and in its flattening. 
All the large Lagence are found at about 50 fathoms (25-70) in shelly sands; the 
more delicate forms occur both in shallow water (which may even be brackish), in the 
dark muds of harbours and bays, and, on the other hand, at great depths, being not 
uncommon in the deposits almost wholly composed either of Foraminifera alone, or of 
these with Pteropods. 
