LOFTUSIA FROM BRITISH COLUMBIA, 75 
tably be compared with that given on plate Ixxix. fig. 1 of Messrs. 
Carpenter and Brady’s memoir. @ indicates a part of the primary 
lamina, which is thickened, as before described, and may consequently 
be seen as a series of rather broad dark zones, indefinite on theirinner 
edges, and running parallel to each other. 0 points out one of the 
secondary growths or septa; these may be seen running parallel to the 
longitudinal axis of the form. They appear wide, from being cut ob- 
liquely, but also, in many cases, from the identification with them of the 
longitudinal rods or rafters formed by the expansion of the pillars. 
At right angles to these, at 2, are seen rods formed by the union, trans- 
verse to the axis, of the distal ends of the pillars. At ¢ the section 
becomes nearly radial, and the pillars are seen as in figure 2. At d 
part of the thickened primary lamina is shown in plan. (X 25.) 
Fig. 4 is nearly longitudinal and radial, representing part of three folds of the 
primary lamina (a) and the pillars uniting them (c). The irregula- 
rities of these are shown, and the cancellated growth from the inner 
side of the lamina is indicated by 2. (x 75.) 
Fig. 5. Portion of the thickened primary lamina shown in plan. At d the 
greater part of the spongy thickening has been removed in grinding 
down the section. The rafter-like thickenings from the intersections 
of which the columns spring are here clearly seen. The darker zone 
surrounding this part represents the primary lamina and its thicken- 
ing (4) obliquely cut. Where, at the edges, the section becomes more 
nearly at right angles to the curved lamina, the pillars may be seen 
running out. (x 79.) 
Fig. 6. Transverse section through the nucleus of a very young specimen, show- 
ing the first convolutions. (x 45.) 
Fig. 7 represents the external form of the organism of actualsize. The figure 
on the right is of an unusually long variety. 
