232 
THE VOYAGE OF H.M.S. CHALLENGER. 
number of individuals with short rays, united together in a colony. It represents seven 
distinct disks, intercommunicating with each other, and forming a sort of network, the 
arms of each serving as stoloniferous tubes connecting it with the adjacent members of 
the group. 
But the most singular specimen which has come under my notice is one which was 
dredged on the coast of Haddingtonshire about ten years ago, by my friend the late 
F. M. Balfour. The test is less thickly beset with mud than usual, and the chitinous 
envelope is correspondingly more apparent ; the disk is of full size, about -^jth inch 
(7 mm.) in diameter, and the rays are small and delicate, and branched at the ends ; but 
proceeding from one side is a tube, of the same texture and substance as the disk, nearly 
an inch (25 mm.) in length, and ^th inch (3’6 mm.) in diameter. It is possible that this 
may be only a monstrous individual of the species under notice. It was dredged in 
company with the typical form, and, except its anomalous contour, and somewhat thinner 
coating of mud, presents no distinctive feature. In specimens showing much irregularity 
it is not uncommon to find one arm a good deal larger than the rest, and the present case 
may perhaps represent an abnormal development of this sort. 
Astrorhiza limicola has been collected at the following localities : — coast of Bohuslan, 
Skager-Rack, Sweden (Sandahl, Loven) ; coast of Norway (Norman) ; off Heligoland, 21 
fathoms (Schulze) ; off Dunbar (F. M. Balfour) ; west coast of Scotland, 10 to 20 
fathoms (Robertson, Herdman) ; Northumberland and Durham, 30 fathoms (Brady) ; 
Torbay, Devon (Norman) ; coast of Connecticut, 25 fathoms, and Maine, U. S. A. (Bessels, 
Verrill). 
Astrorhiza arenaria , Norman (PL XIX. figs. 5-10). 
Astrorhiza limicola, M. Sars, 1868, Vidensk.-Selsk. Forhandl., 1868, p. 248. 
„ „ Carpenter, 1868, Proc. Roy. Soc., vol. xvii. p. 173. 
„ „ G. O. Sars, 1871, Vidensk.-Selsk. Forhandl., 1871, p. 252. 
„ sp., Carpenter, 1876, Quart. Journ. Micr. Sci., vol. xvi. N. S., p. 221, pi. xix. 
„ arenaria, Norman, 1876, Proc. Roy. Soc., voL xxv. p. 213. 
„ „ Brady, 1879, Quart. Journ. Micr. Sci., vol. xix. N. S. p. 43; — 1882, Proc. 
Roy. Soc. Edin., vol. xi. p. 711. 
Test free, compressed ; irregular and branched, or sublenticular and more or less 
radiate, the terminal branches and rays being alike short and thick, and the peripheral 
edges rounded. Walls thick ; built of uniform fine sand with but little cement ; loose 
and granular externally. Interior cavity of the branched variety taking the form of a 
narrow tube, of nearly even diameter except at the points of furcation ; that of the 
stellate variety a central ehamber with radiating tubular passages ; internal surface 
smooth. Aperture at the end of each branch or ray, usually closed with loose sand. 
