TWO GIGANTIC TYPES OE ARENACEOUS EORAMINIFERA. 
741 
Fusulina it is Hyaline and perforate ; whilst in the specimens under consideration it was 
found to be of distinctly granular texture, resembling the built-up ‘tests’ of some of the 
smoother Arenaceous types. The obvious conclusion was that these singular fossils were 
widely separated in organization from their supposed congeners, and that they belonged 
to a new type, which probably bore a similar relation to Alveolina and Fusulina , that 
Trochammina ( incerta ) bears to Cornuspira and Spirillina. At the suggestion of my 
friend and colleague Professor T. Bupert Jones, I propose the generic term Loftusia 
for the type, thereby to associate with it the name of its discoverer, my lamented pre- 
decessor as Secretary to the Natural History Society of Northumberland and Durham. 
27. External Characters. — Most if not all of the specimens of Loftusia that have been 
brought to this country, bear evidence of having formed part of a hard, compact, Lime- 
stone rock, from which they have been separated with the utmost difficulty. Indeed 
the process of mineralization in the animal remains, seems to have gone on simultane- 
ously with changes in the physical character of the calcareous marl of which the matrix 
was originally composed ; and the whole has been converted into a uniform subcrystal- 
line mass, resembling some of the “fossil-marbles” of our Carboniferous system, and 
capable, like them, of receiving a high polish. The rock is traversed by irregular veins 
of white crystalline carbonate of lime, very similar to the material that has displaced 
the sarcode in the chambers and cellular portions of the shells. A piece of the lime- 
stone with the fossils in situ in the Newcastle Collection (Plate LXXVII. fig. 1) shows the 
condition in which they are found. It has apparently been long exposed to the action of 
weather, and is thereby a good deal roughened ; but still it shows how large a proportion 
of the rock is composed of Organic Bemains, chiefly those of Loftusia ; and the course 
which the fracture has taken, right through the fossils at whatever angle they happened 
to lie, without deviating to follow either their periphery or any of their structural lines, 
indicates the determined adhesion which exists between them and the matrix. The 
appearance of the specimens that have been roughly separated on the spot, testifies to 
the same fact ; for scarcely any of them show an exterior surface that can be regarded 
as satisfactorily representing the shell during the life of the animal. The general ex- 
ternal features, however, are readily made out ; and we are in no worse position in re- 
spect to this, than we were with the analogous genus Fusulina , x which until a year or 
two ago was only known from the sections of Limestone in which it occurred ; yet the 
recent discovery of specimens in a free state has done little beyond confirming the accu- 
racy of the conclusions previously arrived at*. 
28. In shape the specimens are all oblong or oval; but they vary considerably in their 
proportionate dimensions. Many of the longer ones taper almost to a point at either 
extremity (Plate LXXVII. fig. 2); whilst a stouter variety (fig. 3) exhibits obtuse 
* [Mr. Beady here refers to the results I have recently obtained from the examination of specimens of Fusu- 
lina kindly transmitted to me hy Mr. C. A. White, of Iowa, U.S. ; which results conclusively establish the cor- 
rectness of the opinion I had founded on the study of less perfectly preserved specimens, that Fusulina belongs 
to the Yitreous or perforated series, instead of ranking with Alveolina (as was supposed by Messrs. Parker 
and T. Rupert Jones) in the Porcellanous or imperforate series. — W. B. C.] 
