MR. H. B. BRADY ON THE RHIZOPODAL FAUNA OF THE SHETLANDS. ' 471 
at Arran, and the single example from Shetland extends its geographical limit still 
further north wards. 
No. 86. PATELLINA CORRUGATA, Will. 
Observed by Mr. George Barlee. (See Rec. For. Gt. Brit. p. 47.) 
No. 90. POLYSTOMELLA ARCTICA, P. & J., MS. (Plate XLVIII. fig. 18.) 
A large, thick-walled Polystomella found in Northern seas. The shell is smooth and 
devoid of the ridges and spinous processes usually found in the typical form, P. crispa. 
The apertures are scarcely visible, owing to the excessive development of shell-substance ; 
but where they are rendered apparent by abrasion or otherwise, they are seen to be double— 
a somewhat striking peculiarity. The terminal chamber is often large. and projecting. 
Diameter =; inch. 
Most, if not all, of my specimens (and I have found it in tolerable abundance) are dark- 
coloured, generally brown, but in some instances quite black ; and this is the more remark- 
able, as the other Foraminifera in the same parcels were beautifully white. This probably 
arises from the deposit or infiltration of foreign matter in the shell-substance whilst the 
thickening process is going on. I have noticed in another species, Nonionina turgida, 
à similar peculiarity with respect to colour, viz. that most of the specimens in some 
dredgings had the large terminal chamber, sometimes the whole shell, much blackened, 
Whilst the other Foraminifera in the same material presented no unusual colouring. In 
this case, however, the colouring was probably due to the food of the animal being of a 
character to produce blackening of the sarcode, which was perceptible through the deli- 
cate transparent shell. We have much still to learn respecting the colour of the sarcode 
in the various species of Foraminifera, which only observations on living specimens can 
teach. 
No. 94. NONIONINA STELLIGERA, d’Orb. (Plate XLVIII. fig. 19.) 
A small, delicate variety of Nonionina asterizans, F. & M., sp., having the stellate 
sutural limbation developed to its fullest extent, with some thickening of the umbilicus. 
D'Orbigny describes a peculiar elbow-like twist in this sutural thickening, which may be 
3n occasional, but is certainly not an invariable character. This species was obtained by 
d'Orbieny in sea-sand from Teneriffe, in which he states it was very rare; in the Shet- 
lands it is also very rare; but it has been found in considerable abundance in the Medi- 
terranean, on the Norwegian coast, and in the Arctie seas. Diameter Jg inch. (See 
d'Orb. For. Canaries, pl. 8. figs. 1 & 2.) 
In the following list will be found named all the species of Foraminifera which p 
been observed in the examination of Shetland sands ; the depth at which they occur, an 
their comparative scarcity, have been appended so far as practicable. 
A single specimen of T'uncatulina refulgens, Montfort, sp-» was um : 2 it was in 
à somewhat distorted condition, and is on that ground omitted from the list. 
Srg 
