118 | PROF. OWEN ON A NEW SPECIES OF EUPLECTELLA 
The present species (Pl. XXI. fig. 1) is six inches in length, two inches across the base, 
whence the cylindroid body gradually expands to near the middle of its length, where it 
presents a diameter of two inches seven lines, and then decreases to the truncated apex, 
which is about one inch and a quarter in diameter; but part of this appears to have been 
torn away. Thus the form of the body is ventricose, not regularly conical as in -Euplectella 
Aspergillum ; it more resembles a cucumber than the shell after which the first species 
was named, whence the present species may be named Fuplectella Cucumer. 
The next difference which strikes the eye is the absence of the oblique and wavy crests 
or ridges which project from the network of the cone, and especially the absence of that 
marginal plate which divides the reticulate terminal cap or lid from the wall of the 
cylinder, standing out like a ruff or frill in Zuplectella Aspergillum. - 
The convex reticulate lid or cap in Æuplectella Cucumer (Pl. XXI. fig. 3) is bounded 
simply by the marginal ridge (figs. 1 & 3,7), which represents the last or lowest* of the 
transverse fibres, but which is thickened by an aceession of the constituent fibrils, especially | 
from the oblique series, so as to project slightly like a rim or ‘bead’ in carpentry. Some 
slightly projecting fibrils from the track of the oblique series of fibres, chiefly multiradiate,. 
and of the kind figured in Pl. XXI. fig. 5, and which scarcely catch the eye, except when 
in relief at the border of the cylindroid, as at p, P, fig. 1, alone feebly represent the parietal 
and reticulate crests which so peculiarly distinguish the Zuplectella Aspergillum. In 
this species the gradual diminution of the cylinder is produced by the convergence and 
confluence of two contiguous longitudinal fibres at certain parts of the circumference. . 
The like convergence and final interblending of contiguous longitudinal fibres, as they 
pass from the free towards the fixed end of the body, is also manifested, though in a 
minor degree, in Euplectella Cucumer, as at c and 6, fig.1. But the gradual expansion of 
the cylindroid is made compatible with this diminution in the number of the longitudinal 
fibres by the divergence of many of the longitudinal fibres as they proceed from the 
marginal ridge, as at d, fig. 1, towards the widest part of the cylindroid, where their 
intervals are greater than in the corresponding part of Buplectella Aspergillum. Very 
few instances of confluence of longitudinal fibres take place before they reach the widest 
part of Euplectella Cucumer : the majority occur beyond it, as at e, e, fig. 1; and besides 
the diminution in number of the longitudinal fibres, they all converge as they approach 
the smaller and attached end of the cylindroid. Here the resolution of the several series 
of fibres into their constituent fibrils seems to take place, at least on one side, viz. that 
A E PL XXI. fig. 1, more abruptly than in Euplectella Aspergillum: on the opposite 
‚as In fig. 2, the fibres in Euplectella Cucumer begin to be resolved into the fibrils or 
"am iiie a ne la Aspergillum. The considerably greater length of 
E sd Å så offer — marked distinction between the two species: but as 
prectella Aspergillum was torn by violence and brought up by the fish- 
ds of attachment, no safe inference can be drawn as to their original 
ength in specimen. In the present example of rof 
Separated silky filaments penetrate, ple of Euplectella Cucumer the delicate 
and, as it were, permeate, the substance of a mass made, 
* i. : 
On the supposition that the Euplectella hangs dependent from its EE 2 
