NOTES ON RETICULARIAN RHIZOPODA, 69 
gens. Professor Sars has been kind enough to send mea 
characteristic sample of this ‘‘ Biloculina-mud,”’ with the fol- 
lowing particulars as to locality : 
“Station 52—Lat. 65° 47:5’ N., Long. 3° 7’ W.; depth 
1862 fathoms ; temperature at the bottom 1:2° Cent.’’ (about 
34° Fahr.). 
The fine impalpable silt had been partly removed 
before I received it, I therefore completed the cleaning 
by washing it thoroughly on a sieve of 120 meshes 
per linear inch, through which no particles larger than 
0:005 of an inch in diameter could pass. The loss was 
about 6 per cent. of the entire weight, and, of the impalpable 
material thus separated, about one half was calcareous, the 
particles evidently consisting of the débris of foraminiferous 
shells, and the other half fine silicious sand. I have no 
information as to the proportion of impalpable mud in the 
dredged material before the preliminary washing, but as 
it is said to be sufficient to incorporate the whole into a 
sticky paste, which on being dried forms a _ hard, light- 
coloured, calcareous mass, it must be considerable. The 
composition of the material as I received it from Professor 
Sars was as follows—the proportions stated are by weight : 
Biloculina ringens (one half being entire shells) . . 50p.c. 
Haplophragmium subglobosum . : : eae, 
Globigerine (the minute arctic form) . ‘ Ae 
Sand and small fragments of rock with a few Forami- 
nifera other than the above-named : a 20k bys 
Impalpable débris_ : d : 5 : Seen 
100 
Assuming that the calcareous part of the impalpable 
mud consists of the disintegrated shells of the same species in 
similar proportions, the total amount of the deposit derived 
from surface organisms would not in this case exceed 4 per 
cent. even were Globigerine at all times pelagic. 
The specimens of Biloculina are very uniform; they are 
of the stout, inflated, typical form, with a small admixture 
of the depressed carinate variety, B. depressa, d’Orb. 
Hardly less remarkable is the existence of so large a pro- 
portion of one of the comparatively small, nautiloid, arena- 
ceous species, Haplophragmium subglobosum ; and here again 
the specimens show scarcely any variation in minor char- 
acters. The Globigerine are all of the minute, subglobular, 
thick-shelled, arctic type, which may be fitly named Gi, 
Dutertrei, var. borealis. Altogether sixteen species of Fora- 
minifera were noted; but beyond those already alluded 
