272 R. T. GUNTHER. 
end of the first part is a full description of the process of 
reproduction by budding in Limnocnida, which was only 
briefly referred to in my preliminary account. 
I. Anatomy.—a. THE EctTopERM. 
The general limiting epithelium of the body does not 
call for particular remark. It consists of a single layer of 
polygonal cells, which vary in height at different parts of the 
surface. On the more exposed surface of the exumbrella they 
are more or less flattened, while on the subumbrella and 
velum they are cubical or even slightly columnar in places. 
The nucleus is roundish, and usually situated in the middle 
of the basal half of the cell. 
Thread-cells were only observed on the tentacles, arranged 
in groups or batteries, on the margin of the umbrella, thickly 
packed in a continuous ring, and on the manubrium, distributed 
along the edge. The exumbrellar surface seems to be com- 
pletely destitute of any such groups of thread-cells as occur in 
the Aiginide or the Geryonide. The thread-cells them- 
selves are very small oval bodies, the major axes of which are 
about twice as long as the minor axes. A peculiar modifica- 
tion of the ectoderm, analogous to the peronium of the 
Trachynemide and Geryonide or to the nettle-ring of 
Limnocodium, occurs all round the rim of the umbrella, just 
outside the circular canal. This ring of modified ectoderm 
extends over the roots of the tentacles, and in it are buried 
the marginal sense-organs (Pl. 18, figs. 1 and 2). The 
minute structure is very similar to that of the peronium of 
other Medusz, and, like that organ, apparently consists of 
modified thread-cells. Its function is possibly skeletal as well 
as defensive. 
Muscular System.—Muscle fibres probably exist both on 
the exumbrella and on the subumbrella, but they could not be 
demonstrated in the material at hand with any degree of cer- 
tainty. The muscles of the velum, however, are very con- 
spicuous, both in preparations mounted whole and in transverse 
sections. The ectoderm of the inner surface of the velum 
