260 
THE VOYAGE OF H.M.S. CHALLEHGEE. 
shown in the sectional view, fig. 14. These characters serve to distinguish the species 
from Hyperammina friabilis and Hyperammina elongata, in which the tube is either 
regularly tapering or of nearly uniform diameter. 
Out of nine localities at which Hyperammina subnodosa has been observed, five are 
in the North Atlantic, the depths varying from 20 fathoms to 450 fathoms, some of the 
finest specimens being from as far north as the coast of Greenland. It occurs also in the 
South Atlantic, off Pernambuco, 350 fathoms ; amongst the East Indian Islands, 1425 
fathoms ; in the North Pacific, 2300 fathoms ; and in the South Pacific, near the 
equator, 2600 fathoms. 
Hyperammina vagans, H. B. Brady (PI. XXIV. figs. 1-9). 
Hyperammina vagans, Brady, 1879, Quart. Journ. Micr. Sci., vol. xix. X. S., p. 33, pi. v. 
fig- 3. 
„ ,, Haeusler, 1883, Quart. Journ. GeoL Soc., vol. xxxix, p. 26, pL ii.figs. 2-6. 
Test more or less adherent ; consisting of a spherical or oval primordial chamber, 
opening into a long unbranched tube of nearly even diameter, sometimes partially free, but 
more commonly spreading in irregular tortuous lines over the surface of shells or stones, 
or, in the absence of foreign bodies, growing coiled upon itself in irregular masses ; the 
open unconstricted end of the tube serving as the general aperture. Walls thin ; texture 
arenaceous ; surface tolerably smooth ; colour brown, the primordial chamber usually of 
darker hue than the tube. Length indefinite ; diameter of the tube from -g-^yth to xirAh 
inch (’05 to *2 mm.). 
In some areas the fine arenaceous tubes of this or other similar Rhizopod are found to 
a greater or less extent on almost every fragment of shell or stone presenting a surface 
favourable to their growth. It is rarely, however, that the specimens are even 
approximately complete or perfect ; and the primordial chamber being almost invariably 
wanting, such organisms were for a long time passed over, under the supposition that 
they were the tubes of parasitic annelids. The tubular portion of the test is of indefinite 
length, and always seeks some solid basis to spread itself upon, in the absence of which it 
is occasionally found in little masses formed of irregular coils adherent to each other. The 
bulbous end is often quite free, projecting above the remainder of the test, from which 
it does not otherwise differ in external characters, except that it is of a darker reddish- 
brown colour. There is sometimes a slight constriction or articulation at the point where 
the chamber joins the tube, as shown in figs. 4 and 5. 
Hyperammina vagans differs from Hyperammina elongata and Hyperammina 
ramosa in its parasitic habit : from the former also in the great length and tortuous 
course of the tubular portion, and from the latter in the simple unbranched contour of its 
