^"Kunmi/Ma^^^^^^ Royol MieToscopical Society. 269 
part of that of G. M^enas, and a rod projecting from its centre ; 
this rod, unlike tlie corresponding part in G. Msenas, projects only 
on one side ; in this case the sphere of the latter is flattened out, 
and in the process becomes somewhat larger, measuring 0 * 005'""^ 
across ; thus far the same elements exist in both ; but M. verru- 
cosa has in addition four or five fine lines projecting in a radiating 
manner from the circumference of the disc; in Stenorhyncus 
Longirostris (Fig. 2(X and h) this species of zoosperm is exhibited 
in a slightly higher form. Here, also, the basis is a disc, thick and 
bevelled ofl' on one side, on the other projects a rod, v^hich rises in 
a series of steps to its summit, having for its base a broad pedestal, 
on which is a short piece of less diameter ; on this, again, is another 
still smaller, the whole having the appearance of a telescope drawn 
out to its full length ; the circumferential rays are usually five or 
six in number, although often one or more of them are wanting ; 
they seem to be composed of a fine transparent matter, very thin 
and slender, so as to be almost invisible ; they have apparently the 
same character as the vibratile cilium of monads, but instead of 
being flexible and mobile, they are stiff" and motionless, or rather 
they recall to mind the rays of Actiiiophrys Sol. The disc measures 
across 0 • 007'"™ ; it has a slight tendency to deviate from the round 
to the pentagonal form ; on looking at it from above, one sees a 
spot in the centre, this is the rod; round this is a circular line, 
which marks the edge of the pedestal, outside which is the surface of 
the disc; this is seen more plainly (Fig. 2c) in younger zoosperms. 
Viewed on the side, the zoosperm presents a flat surface in front, 
bounded by a dark line, upon which is placed the pedestal of the 
rod, not always in the centre, and from the edges of which arise 
the rays, projecting upwards and forwards; behind this line is 
a broad band of transparent substance occupying the whole breadth 
of the disc ; its hinder contour is slightly concave, but the contour 
of the disc, being convex, the small space left between the two is 
filled by a darker material ; in another specimen the huider con- 
tour of the disc was flat, the latter matter being absent. 
In the Hermit Crabs (P. Bernhardus) an advance in com- 
plexity of structure is visible ; the head is a conical body in shape, 
somewhat like a rifle-bullet ; there are rays and a motionless tail, 
but no rod. To enter into detail, a zoosperm (Fig. 3a) placed on its 
side presents for examination a head either sharply conical or with 
one end rounded, approaching the spherical in form ; from the base 
of this project, at a greater or less angle, three sharply-pointed 
rays ; they are longer in proportion to size of the head than those 
of S. Longirostris ; in most cases they are simply attached to the 
head, but in others their roots appear to penetrate into its interior to 
meet in the centre, their point of junction (Fig. W) being marked by 
a bright spot ; this is analogous to the case of G. Msenas, where the 
u 2 
