344 
MR. W. K. PARKER AND PROEESSOR T. R. JONES ON SOME 
the chief Nodosarine characters, the Marginulince form the central group of the Nodo- 
sarince, and Nodosarina ( Marginulina ) JRaphanus is the type of all. 
Very large specimens of M. Litnus occur at Nordland, Arctic Circle (Mac Andrew and 
Barrett), on a muddy bottom, at 160 fathoms. These are the largest individuals we 
have ever seen of this common variety of Marginulina or uncoiled Cristellaria, which 
is to be met with wherever the Cristellarians occur, recent or fossil, from the Lower , 
Secondary deposits upwards. 
In this case Cristellaria cultrata is also present ; and an analogous companionship of 
the Cristellarian and the Marginuline Nodosarince is to be found in Professor Bailey’s 
“Microscopical Examination of Soundings made by the United States’ Coast-survey off 
the Atlantic Coast of the United States” (Smithsonian Contributions to Knowledge, 
vol. ii. 1851), where two forms ( Nobulina D'Orbignii and Marginulina Bacheii, Bailey), 
equivalent to the above, accompany each other in soundings of from 51 to 90 fathoms. 
(See above, page 331, and Appendix II.) 
Cristellaria Crepidula , Eichtel and Moll, sp. Plate XIII. figs. 15, 1 6a, 16 5 (Arctic); 
Plate XVI. fig. 4 (North Atlantic). 
We have here a very insensible gradation from Marginulina Lituus (fig. 14). In fact 
fig. 15 differs but little from the latter except in size; and fig. 16 is merely somewhat 
more closely coiled, flatter, and shorter ; thus putting on the true Cristellarian form. 
These specimens are from dredgings made at the Hunde Islands by Dr. P. C. Suther- 
land ; they are rather common in the sandy mud, rich with shells, at from 30 to 40 and 
60 to 70 fathoms. 
In recent occurrence C. Crejtidula is as world-wide as the ordinary Bentalince. It is a 
feeble form of Cristellaria creeping up from the favourite depth of Cristellariae (50 to 100 
fathoms) to shallow water, and downwards to abyssal deeps. 
In the fossil state also it has an equally wide range ; but, like its congeners, it is met 
with of a larger size in the Upper than in the Lower Secondary deposits. The largest 
are to be found in the Subapennine and Viennese Tertiaries ; some of these large fossil 
varieties are extremely thin. 
Plate XVI. fig. 4 (North Atlantic). 
A pretty little C. Crepidula , differing only as an individual from fig. 16 in Plate XI. 
Small and rare at 43 fathoms, lat. 51° 57', long. 10° 30', North Atlantic. 
Cristellaria cultrata, Montfort, sp. Plate XIII. figs. 17 a, 17 b, 18 a, 185 (Arctic); 
Plate XVI. fig. 5 (North Atlantic). 
This is Cristellaria proper, the most nautiloid form attained by any Nodosarina. Here 
the rod-like chain of chambers seen in the simple forms ( Nodosaria ) has passed into a 
spiral, discoidal, symmetrical, lens-shaped shell ( Cristellaria ). In this variety, C. cul- 
trata, the shell is more or less keeled ; this keel becomes more developed and rowelled 
