28 
PROaRESS OF MICROSCOPICAL SCIENCE. 
structure was faintly yellowish or nearly colourless. A specimen of 
eighteen cells was ^ of a line long, with the last cell about of a 
line in diameter. 
An interesting Rhizopod, not pertaining to the Polythalamous 
foraminifers, to which my attention was directed by Professor 
Verrill, frequently occurred in the mud dredged off the Connecticut 
coast. 
The same creature is referred to by Professor Verrill in the Report 
of the Commissioner of Fish and Fisheries for 1871 and 1872, page 
603, as being extremely abundant in the clear silicious sand dredged 
from Vineyard Sound. 
The creature was discovered by Dr. Sandahl in the Bohnslaiis 
Archipelago, and is described in the Of vers. K. Vetensk. Ak. Forh., 
Stockholm, 1857, 301, under the name of AstrorJiiza limicola. It is 
also referred to in Thomson's ' Depths of the Sea,' p. 76, as occurring 
in the Atlantic ooze off the Faroe Isles. 
The case of this Rhizopod is constructed of angular particles of 
quartz sand, cemented by tenacious matter mingled with the finest 
dark-coloured mud. The body of the case is discoid or lenticular, 
with a number of short cylindroid processes radiant from the margin, 
giving the case altogether an irregular stellate form. 
Sandahl describes the shell as exhibiting scattered yellowish- 
brown spots, unequal, irregular, and somewhat shining. These spots, 
in the specimens examined by me, are due to the translucent quartz 
particles through which the yellowish colour of the interior soft 
structure of the animal is seen. Sandahl gives the number of radii 
from 10 to 15, and the size of the case from 3 to 4 lines. Our 
specimens measured from 2^ to 4 lines, and exhibited radii from 6 to 
13 in number. 
The interior soft substance of the little mud stars is a viscid, 
mucoid matter. The ectosarc is colourless. The entosarc was 
granular and yellowish, sometimes containing ova-like bodies, with 
darker yellow or orange-coloured contents. Besides these the 
entosarc contained clear globules and a multitude of diatoms, princi- 
pally a species of Coscinodiscus. 
He failed to see the Astrorhiza in a very active condition, pro- 
bably from the hot summer weather too quickly giving rise to 
decomposition in the material collected. Only in two instances did he 
discover the animal with a number of delicate filamentous pseudopods 
projected from the processes of the disk. The pseudopods as seen, 
and as represented by Sandahl, are like those of the Foraminifera. 
In the single-chambered character and structure of the case, 
Astrorhiza resembles the fresh-water Difflugia, but differs in having 
many orifices, to protrude the pseudopods, instead of a single one. 
American Observations on Stejphanoceros. — This animal, which has 
been so well worked out by Mr. Cubitt in these pages, has recently 
had American attention devoted to it. In the * Proceedings of the 
Philadelphia Academy of Sciences ' for April, 1875, Mr. C. Newlin 
Peircc exhibited drawings of a specimen of an aquatic animal, 
belonging to the genus Stephanoceros, which had been recently 
