REPORT ON THE FORAMINI FER A. 
261 
extensions. There is only one common Foraminifer with which it is at all likely 
to be confounded, namely, Wehbina clavata, J. and P., but the primordial chamber in 
that species is a simple, adherent, tent-like, shelly dome, and the tube a semi-cylindrical 
covering — neither chamber nor tube having any floor proper to itself. 
Messrs. Nicholson and Etheridge, in their valuable Monograph of the Silurian 
Fossils of Girvan in Ayrshire, fasc. 1, p. 23, pi. ix. fig. 24, have described, under the 
provisional name Girvanella, a tubular organism occurring abundantly in little masses 
in the “ Craighead Limestone,” with the following generic characters “ Microscopic 
tubuli with arenaceous or calcareous (?) walls, flexuous or contorted, circular in section, 
forming loosely compacted masses. The tubes apparently simple cylinders, without 
perforations in their sides, and destitute of internal partitions or other structures of 
similar kind.” This description applies in every particular to such specimens of 
Hyperammina vagans as are represented in figs. 7 and 8 ; and the specific characters 
which follow agree equally well, except in a single point, namely, that the diameter 
of the tubes in Girvanella is from y^th to -g^yth of an inch, whereas those of the 
present species range from -y^-th to xihj-th of an inch. Some latitude must be allowed 
in estimating the characters of a minute fossil belonging to so very remote an age, but it 
seems scarcely worth while to recognise these trifling differences as a basis of generic 
distinction. 
Hyperammina vagans is a cosmopolitan species. It is found as far north as Spits- 
bergen and as far south as Kerguelen Island, and occurs in all the great ocean basins. 
Specimens dredged by the Rev. A. M. Norman, off Oban, on the west coast of Scotland, 
give it a place in the British fauna. Its bathymetric range is correspondingly wide — 
from 15 or 20 fathoms in the Arctic Sea, to 2900 fathoms in the North and South Pacific. 
Of the probability of its existence as a palaeozoic fossil nothing more need be said. 
Dr. R. Haeusler has been good enough to send me a number of specimens, wmnting in 
nothing but colour, from beds of Jurassic age in the Canton Aargau, Switzerland. 
Hyperammina ramosa, H. B. Brady (PI. XXIII. figs. 15-19). 
Hyperammina ramosa, Brady, 1879, Quart. Journ. Micr. Sci., vol. xix. N. S., p. 33. pi. iii. 
figs. 14, 15. 
Test free ; consisting of a subglobular primordial chamber with a tubular extension. 
Tubular portion branched ; relatively wide at its commencement, but narrowing as it 
becomes divided, the later branches of tolerably even diameter. Texture generally 
loosely arenaceous ; exterior rough, often beset with sponge-spicules. Length indefinite. 
This organism never attains the dimensions of the allied Hyperammina friabilis or 
Hyperammina subnodosa. The texture of the test is coarse ; the surface rough, and 
usually, though by no means invariably, hispid, owing to the number of adherent, or 
(ZOOL. CHALL. EXP. — PART XXII. 1883.) Y 34 
