68 FORAMINIFERA OF THE CRAG. 
shell. We have never seen it so abundant as in some sands dredged in from thirty to 
forty fathoms, in Berwick Bay, and in that locality the finely grown Vaginuline were 
found to be almost without exception in the ribbed condition. It is impossible’ to dis- 
tinguish the smooth, slender, depauperated forms of Vaginulina from Dentalina communis ; 
indeed, the two varieties merge insensibly into each other, whilst the costulate Vaginuline 
are barely separable from D. ob/iquestriata. 
V. linearis is not uncommon in a recent condition on our own shores, though it 
appears to be somewhat local in its distribution, and the same remark applies to its 
occurrence in seas of both colder and warmer latitudes. 
In a fossil state it is less common, but it is occasionally met with in beds belonging 
to the Secondary and Tertiary periods. 
Subgenus—Mareinvuina, D’ Orbigny. 
NautiLus, OrTHOCERAS, ORTHOCERA, CRISTELLARIA, ORTHOCERINA, 
HEMICRISTELLARIA, ductorum. 
MarGinuuina, D’Orbigny, Cornuel, Roemer, Reuss, Neuegeboren, 
Bornemann, Parker, Jones, Brady, Terquem, Karrer, Costa, Se. 
Characters.—Shell elongated, subcylindrical or flattened, straight or arcuate, tending 
to spiral mode of growth in the earlier chambers ; ornamented with ribs, granules, spines, 
&c., as other MVodosarine. Aperture nearly always excentric towards or close to the 
convex margin of the shell. 
The difficulty of defining any special groups among the Marginuline Nodosarine is 
insuperable, every character being variable, namely, the excentricity of the axis of the shell 
(whether amounting to spirality or simply to a curvature), the compression, and the orna- 
mentation, which last has the same patterns as in other Wodosarine. 
We may take the simple smooth J/arginuling as one group; but we are baffled by the 
ever-varying proportions and shape among them; and, khesitating to adopt a name for 
every individual, we are obliged to take J/. glabra (see further on) as a subtype, though 
it graduates in form into Vaginulina, Dentalina, and Nodosaria, on one hand, and into 
Cristellaria on the other ; whilst, as to ornament, it takes on more or less of the exogenous 
shell-growth, thus becoming any one of the hispid, costate, limbate, or otherwise orna- 
mented varieties. 
For another subtype in our artificial grouping, we may take the ribbed JZ. raphanus, 
to be presently described. For another, the keeled forms J/. carinata, D’Orb.,’ and 7. 
angistoma, Stache,” may serve. A fourth group may comprise the limbate varieties, either 
1 «Ann. Se. Nat.,’ vol. vii, p. 259, No. 8. 2 *Novara-Exped., &c., pl. 22, fig. 46. 
