348 
PROFESSOR W. WILLIAMSON ON THE ORGANIZATION 
the outer surface of part of a crushed specimen in which the perfect contact of all 
the outer expanded extremities of the cells composing the wall of the organism is 
clearly shown. 
The hairs, c, which project from the outer surface of these specimens are merely 
the external dilated extremities of some of these cells prolonged outwardly. They 
are very turgid at what, viewed externally, appears to constitute the base of each 
hair, but at their peripheral portions they are drawn out into long cylindrical, 
uncellular structures, c c" , which appear in some instances to be bifid or trifid at then' 
extremities. Each hair therefore appears to consist of a single cell, the lower end of 
which is at first turgid, then dumbbell-shaped, the latter portion being prolonged 
through the wall of the organism, so as to reach its inner surface. 
These objects have obviously been spherical bodies. In fig. 67, d, we find an organic 
spherical tissue occupying the interior of the organism. The latter has a shrivelled 
membraneous look about it, but otherwise displays no traces of structure. 
Fig. 69a, is another specimen of the same conceptacle from one of Mr. Earn, shaw’s 
slides. In it, the central membrane seen in fig. 67, d, is filled with small spherical 
cells, the protoplasmic contents of some of which, as at a, have become contracted 
and detached from the cell-wall. In other respects this example exhibits the same 
structure as is seen in figs. 67 and 69. These objects may be distinguished provi- 
sionally as Sporocarpon elegans. 
I am acquainted -with no recent objects that exactly correspond with these 
conceptacles. There is some little resemblance between them and the outermost layer 
of the sporangiocarp of Pilularia globulifera. In this latter structure we have a layer 
of large cells, many of which are prolonged externally into conspicuous hairs, each one 
of which has a turgid base like those of my fossil ; but the subjacent hour-glass form 
of each cell is entirely wanting in the recent type. 
Mr. Binns, Mr. Spencer, and Mr. Earnshaw, have furnished me with slides 
from the Halifax beds, containing examples of the remarkable type of conceptacle 
represented in figs. 76a/" 78, and 78a. Fig. 76, a, for the original of which I am 
indebted to Mr. Binns, represents a sphere composed of a single layer of oblong cells, 
a, the inner ends of which are flattened and in close contact so as to bound a very 
regular and smooth internal, spherical cavity. These cells continue in close contact 
throughout the greater part of their length, but their peripheral extremities are free, 
and more or less rounded. The dark circle, b, in the figure, represents a portion 
of this smooth inner bounding wall of the cavity which happens not to have been cut 
through, at either surface of the section, in the plane of its greatest diameter. At c 
we have a collapsed inner and apparently structureless membrane apparently cor- 
responding to d in fig. 67. At the first glance this conceptacle appears similar to 
that represented by figs. 75, 76. But this difference exists between the two: in 
the former the bounding wall of the conceptacular cavity consists of a single layer 
* I Lave already referred to this figure in p. 182. 
