CRETACEOUS FORAMINIFERA. 47 
Operculina complanata var. granulosa.] 
Operculina granulosa. B, 12, a, b, c. “Cette petite operculine, que l’on trouve 
dans les mémes gisements que la précédente, nous parait devoir en étre séparée. 
Elle est constamment plus petite ; ses cloisons, quise montrent enformant un léger 
relief la surface du tesf infiniment mince qui renferme les spires, sont ici proportion- 
nellement plus serrées. Cette espéce trés plate se compose de 3 a 4 tours de spire. 
Elle porte a sa surface, de chaque coté, un certain nombre de fines granulations qui 
se trouvent irréguliérement distribuées sur les petites cotes en relief qui correspond- 
ent aux cloisons interieures. Ces points saillants, rares sur les derniers tours, se 
trouvent agglomérés au centre chez beaucoup d’individus. Diamétre, 4 a 5 millim.” 
Operculina granulosa. B, 12 a,b, ec. This little Operculina, which is found in the 
same layers as the preceding (0. ammonea), appears to us worthy of separation. It 
is uniformly smaller ; its partitions, which form a slight relief upon the surface of 
the very thin shell which encloses the whorls, are proportionally more approximate. 
This species is very flat, and is made up of 3 or 4 spirals. It carries on its surface 
on each side, a number of fine granulations, which are found irregularly distributed 
upon the little elevations which correspond to the interior partitions. These pro- 
jecting points, scarce upon the last whorls, are found crowded towards the centre in 
many individuals. Diameter 4 to 5mm. 
As there seems to be some doubt and diff.rence of opinion in regard to the species 
and variety, we will give in addition to the above description the generic diagnosis 
of H. B. Brady. 
“The test of the typical Operculina is a thin complanate disk, composed of three 
or four broad convolutions symmetrically arranged and equally visible on both faces. 
The central portion of the disk is usually somewhat thicker than the outer whorls, 
and not unfrequently almost umbonate ; the earlier convolutions are more or less 
embracing, the later whorls evolute. The segments are usually very numerous, of 
gradually increasing size, and typically very short in the direction of growth, as 
compared with their width radially; they are for the most part produced on a 
uniform plan, but near the finish are often irregular, both as to shape and size (PI. 
exii, figs. 3, 4 and 6, Rept. Foram. Challenger). The exterior is sometimes smooth, 
but, more frequently, either the sutures or the surface of the chambers, or both, are 
ornamented with exogenous granules, papillae or tubercles, which, as a rule, are 
more strongly developed near the centre than on the later whorls ; and in the small 
northern variety of the genus, the septal lines and periphery are distinctly limbate. 
The general aperture is a straight or slightly curved fissure at the inner margin of 
the final segment, close to the periphery of the previous convolution; but the test 
has frequently also a number of secondary orifices, in the form of small circular 
