NOTES ON RETICULARIAN RHIZOPODA. 47 
from the west coast of Scotland.! At times it is not easily 
distinguished from Beloculina contraria, for the internal 
structure is obscured by the thickness and opacity 
of the test; generally, however, there are slight con- 
strictions or depressions at the periphery, marking the 
sutures. 
H. circinata, nov.—Test nautiloid, thin, complanate; com- 
posed of two or three convolutions, the last, consisting 
of six or seven segments, completely enclosing the 
earlier ones. Segments arched, rounded at their peri- 
pheral margins; sutural lines marked by external con- 
strictions. Colour milky white, sufficiently translucent 
to show the outline of the inner whorl of chambers. 
Aperture consisting of a number of perforations distri- 
buted irregularly over the front of the terminal seg- 
ment. Diameter ~/; inch (1° mm.). 
vo 
Orsito.ites, Lamarck. 
Orbitolites laciniatus, nov.—A variety of Orbitolites of the 
complex type, figured by Carpenter (‘ Phil. Trans.,’ 
1856, pl. 5, figs. 2, 3), and by Butschli (in Bronn’s 
‘ Klassen und Odrnungen des Thier- Reichs,’ 1880, vol. i, 
pl. 5, fig. 4), but in both cases without name. It is little 
more than a local variety of Orditolites complanatus, 
abundant on the coral reefs of the Friendly Islands and 
Fiji; but as it represents the best development of the 
structural modifications induced by redundant growth, 
it is convenient that it should be distinguished by 
name. 
The centre of the disc is constructed on the normal 
plan, but near the margin it becomes strongly sinuate 
or plicate, at the same time splitting so as to forma 
double periphery, the two edges of which approximate 
at intervals, but otherwise are separated by deep 
irregular furrows. Specimens from the localities above- 
named are not unfrequently an inch (25° mm.) or more 
in diameter. 
As?RoruizA, Sandahl. 
Astrorhiza crassatina, nov.—Test (typically) elongate, sub- 
cylindrical, seldom of uniform breadth, often constricted 
near the middle, ends rounded ; consisting of a tube of 
greater or less length open at both ends. Walls very 
1 “ Rhizopodal Fauna of the Hebrides,” ‘ Report Brit. Ass.,’ 1866 (Trans. 
Sections), p. 69. 
