234 
THE VOYAGE OF H.M.S. CHALLENGER. 
cavity is often constricted near the middle, though not to the extent of actual segmenta- 
tion. The apertures, which are terminal, are frequently rendered labyrinthic by partial 
closure with loose sand-grains. 
Astrorhiza crassatina was obtained on the third cruise of the “ Porcupine” in 1869, 
from dredgings in the Faroe Channel, at a depth of 640 fathoms. The figured speci- 
mens are nearly all from Dr. Carpenter’s collection. 
Astrorhiza granulosa, H. B. Brady (PI. XX. figs. 14-23). 
Marsipella granulosa, Brady, 1879, Quart. Journ. Micr. Sci., vol. xix. N. S., p. 36, pi. iii. 
figs. 8, 9. 
Astrorhiza granulosa, Id. 1881, Ibid. vol. xxi. p. 48. 
Test fusiform, tapering nearly equally towards both ends ; cavity tubular, of approxi- 
mately uniform diameter. Walls thickest in the middle of the test, composed of fine 
grey sand ; exterior loose and granular, interior nearly smooth. Apertures simple and 
terminal, either open or partially closed with sand-grains ; often tinged brown. Length, 
^th inch (6 to 7 mm.) or more. 
It is possible that Astrorhiza granulosa may be only a local variety of Astrorhiza 
crassatina ; but the smaller and more regular test and the uniform width of the tubular 
cavity are sufficiently distinctive in the specimens which have come under my notice. 
The polystomous modification, Astrorhiza angulosa, also differs considerably from the 
corresponding species of the more northern area. 
Astrorhiza granulosa has only been found at a single Challenger Station, No. 78, 
east of the Azores, depth 1000 fathoms ; at which locality it is tolerably abundant. 
Astrorhiza angulosa, H. B. Brady (PI. XX. figs. 10-13). 
Astrorhiza angulosa, Brady, 1881, Quart. Journ. Micr. Sci., vol. xxi. N. S., p. 48. 
Test subtriangular (rarely quadrangular), depressed, biconvex ; peripheral edge 
rounded : consisting of a small central chamber with radiating tubes, one of which passes 
to each corner, the open ends serving as apertures. Texture and substance of the walls 
similar to Astrorhiza granulosa. Diameter about ^th inch (4 mm.). 
Astrorhiza angulosa appears to be a short three-mouthed variety of Astrorhiza 
granulosa, with which species it is found associated. In these, as in some other modifi- 
cations of the genus, the orifices are often blocked with loosely aggregated sand, and are 
not unfrequently stained reddish-brown. 
The figured specimens are all from Station 78, east of the Azores, depth 1000 fathoms ; 
