Mr. H. J. Carter on Ramulina parasitica. 101 
diameter. Diagrammatic sketch taken from a slice of Orbito- 
htes Mantelli, var. Theobaldi, reduced to translucent thinness 
und cut a little obliquely, so as to show part of the central plane 
overlain by the crust. a, cells of the central plane; 4, cells of 
the crust; c, globular lobes of the Ramulina confined to the 
cells of the central plane and joined together by a common 
stulon; e, the zigzag form; ff, lobes in the “ free state” 
more or less multiangular and joined together by stolons, 
presenting in the aggregate a reticuliform character like that of 
the capillitiuim of some of the Mycetozoa; g, lobes united to- 
gether directly. 
Fig. 2. The same. Portion in the “free state,” more magnified, to 
show :—a, the lobe or chamber ; 4, the stolon; ¢¢c, tubuli pro- 
jecting from the surface of the chamber; d, chambers below the 
surface unfinished ; ee, two chambers united together. Taken 
from the polished surface of a fragment of the rock containing 
the said Orbitolites, where the chambers of the Ramulina 
appear at different depths in the transparent crystalline matrix. 
(On most of the chambers the tubuli are omitted for perspicuity 
and to save trouble in drawing.) 
Fig. 3. The same. Single chamber, more magnified, to show the tubuli 
and their position on the surface im situ (fig. 3a). Fig. 36 
represents a small fragment of the surface of the chamber mag- 
nitied to the scale of 1-48th to 1-3000th of an inch, to show that 
the bases of the tubuli are respectively situated in the centre of 
grains of calcite, which appear to have a polygonal shape. 
Fig. 4, The same. Two chambers, much magnified. Taken from the 
surface of the polished fragment, where their upper parts have 
been ground off, thus showing a, the thinness of the wall, and 
b, the reticulated structure in the interior of the chamber, at 
the same time. 
Fig. 5. The same. Group in which both sides of the lobe, a, have been 
ground down, thus again showing the reticulated structure 
ot the interior, but by transmitted light; 6, one in which 
the section has not gone below the surface, showing the trun- 
cated ends of the tubuli; ¢, unfinished lobe. Taken from a 
microscopic slice which had been reduced to translucency. 
Fig. 6. The same. Five cells of the central plane obliquely cut across, 
so as to show the structure of the globular lobes which they 
respectively contain gradationally. a, cells of “ central plane ;” 
b, opaque state of “globular lobe” uncut; c, showing indis- 
tinctly traces of the (?) reproductive bodies which it contains ; 
d, the same more distinct; e, the same still plainer; f, the 
thinnest section of all, in which the reproductive elements 
appear to consist of spherical cells, g, imbedded in the reticu- 
lated tissue; , stolon. All the parts of this illustration are 
magnified to the scale of 1-48th to 1-6000th inch and taken 
from a mounted microscopic slice. 
