EEPOET ON THE FOEAMINIFEEA. 
231 
Astrorhiza limicola, Sandahl (Pl. XIX. figs. 1-4). 
Astrorhiza limicola, Sandakl, 1857, Ofvers. af Kongl. Vetenskaps-Akad. Fork and!, vol. xiv. 
p. 299, pl. iii. figs. 5, 6. 
Astrodiscus arenaceus, Schulze, 1874, II. Jahresberiehte d. Korn. Untersuch. d. deutsch. Meere, 
p. 113, pl. ii. fig. 10, a.-e. 
Haeckelina gigantea, Bessels, 1874, Jenaische Zeitschr., vol. ix. p. 265, pl. xiv. 
Astrorhiza i limicola, Norman, 1876, Proc. Boy. Soc., vol. xxv. p. 213. 
„ „ Brady, 1879, Quart. Journ. Micr. Sci., vol. xix. N. S., p. 43. 
Test compressed, irregularly stellate ; consisting of a central disk, with peripheral 
tubular arms, radiating in one plane. Arms 8 to 15 in number, irregular in form, 
slender ; very variable in length, sometimes longer than the diameter of the disk ; often 
divided at the end into a number of little tubular branches. Walls thick, composed of 
indiscriminate mud with more or less distinct chitinous lining ; exterior rough, internal 
surface smooth. Colour greyish-brown, sometimes marked with yellowish-brown spots. 
Diameter of the disk about -|th inch (5 mm.); the entire test, including the rays, 
often measuring \ inch (12 or 13 mm.) or more. 
There can be no doubt as to the particular organism for which the name Astrorhiza 
limicola was intended by Dr. Sandahl ; the figures of the test, as well as the terms of 
the description, accord accurately with the form familiar to naturalists who have 
dredged in shallow water on our own coast, or elsewhere in northern temperate latitudes. 
The most characteristic feature of the species is the peculiar structure of the investment. 
It is not sandy, like that of the deep-sea varieties with which it has been frequently con- 
founded, but the exterior is composed of mud, taken apparently without any selection from 
the miry bottom on which the animal lives. Within this layer of mud, which though toler- 
ably firm is not incorporated by any inorganic cement, is a sort of chitinous envelope which 
lines the whole test and imparts a smooth surface to the interior. The muddy coating 
of the arms is thinner than that of the body of the test, and the small tubular processes 
into which the extremities are divided have so little extraneous covering that they shrivel 
and crumble away on being taken out of fluid, and are seldom seen in dried specimens. 
The proportionate dimensions of the disk and the rays vary considerably. In Sandahl’s 
drawing the disk is of about the same diameter as in the specimen represented in fig. 1, 
but the length of the rays is only about one-fourth the diameter of the disk. They are 
relatively broad, the ends are round and open, and long granular pseudopodia are shown 
issuing directly from them. 
Dr. Bessels, who has studied living specimens obtained upon the coast of the New 
England States of North America, gives a drawing ( loc . cit.) of a specimen of very 
similar proportions to fig. 1, but the disposition of the rays is rather more regular, and 
some of them have divided ends. The same author has also an interesting figure of a 
