200 On the Phosphorescence of Marine Invertebrata. ° 
Spongodium vermiculare, as also other Alge regarded as phos- 
phorescent, owe this appearance only to the luminous animal- 
cules adhering to their surface. He describes a new species of 
Polynée (P. fulgurans) found by him in the Baltic, that appa- 
rently plays an important part in the phosphorescence of that 
sea, which also owes its luminous properties to different infa- 
soria. At Christiana and at Helgoland, Ehrenberg observed this 
phenomenon in many species of Meduse; at the last locality 
he met with the Noctiluca miliaris, which he calls Mammaria. 
Ehrenberg describes also the very remarkable mode of phosphot- 
escence which appeared in a Nereid, the Photocharis cirrhigera. 
In that Annelid, the light proceeds from two thick and fleshy 
cirri belonging to the dorsal branch of the feet. The author 
observed sparks, at first isolated,.invade the cirri by degrees, 
until they became luminous in their whole extent; then the 
phosphorescence spread through the whole back, until the animal 
looked like a thread of burning sulphur. The mucus secreted 
a chaplet around the border; these correspond to the large cirri 
sparks, following each other in quick successions, under the yore 
. * t “ 
not always, there is formed by this production of sparks, a muC™, 
laginous humor, gelatinous or aqueous, which is diffased around 
in great abundance, and is evidently placed in a scconeet og 
eve lasts after that has been divided or destroyed. uil 
ight which to the naked eye appears uniform and ae 
shows itself scintillating under the microscope. 
and 
