8 
INCIDENTS OF THE VOYAGE. 
projecting from the month of the little Spirulai and 
throwing out their cirri with all the regularity and 
energy of the larger species. But the most curious 
thing was a small Porpita, a flat, circular Medusa of 
about one-sixth of an inch in diameter. It consisted 
of an annular disk, perfectly pellucid, inclosing an 
opaque central portion, occupying about two-thirds 
of the breadth, which seemed to he composed of 
fibres radiating from the centre. On the under sur- 
face this central part was flesh-coloured with a blue 
margin ; and while alive, as it floated, I perceived 
on it several teat-like projections, which had a slug- 
gish motion. On the upper side the pellucid mem- 
brane was continuous, and had a glistening appear- 
ance ; the opaque part was here light brown. On 
being handled, the little animal gave out a milky 
fluid, which clouded the water. 
I afterwards obtained several more of this minute 
Porpita, some of which were very beautiful; the 
margin being fringed with numerous oviducts (?) of 
varying length, which were transparent, hut studded 
and terminated with knobs (germs ?) of a deep blue 
colour. In the centre of the under surface was a 
fleshy sucker, and around it many teat-like projec- 
tions, like the tentacles of an Actinia; these I saw 
thrown out and suddenly retracted irregularly, and 
independently of each other.^ All these surface- 
* As this seems hitherto undescribed, I propose for it the name of 
Porpita {polyhrachionea) minuta. It differs greatly in size from those 
hitherto described, being only one-sixth of an inch in diameter, while 
Bose compares P. gigantea to a 24 sous piece, and P. glandifera 
(figured, of the natural size, in the Phil. Trans, vol. xxiv. p. 2053) 
