SWIMMING ASCIDIANS. PAL! 
scurer parts of the creation. Many of these animals 
have occasionally fallen under my notice; but amid 
pursuits which rendered it impossible to attend 
either to their examination or preservation. I have, 
however, preserved a memorial of one, as it appears 
to form a new species, in a tribe of which no indi- 
vidual has yet been observed within the limits of 
the British seas. It belongs, apparently, to the 
genus Salpa. .. . 
“The mode in which the republic is linked 
together, is observed to be constant in each species; 
and it is sufficiently remarkable in this one, to 
distinguish it from the rest of the genus, as far as 
it is yet described. Hach individual adheres to the 
preceding, by a regular sequence of superposition, 
lengthwise ; so that the whole forms a long, simple 
chain, the adhesion continuing as in the ovarium, 
for some time after hatching. They were found 
from the middle to the latter end of August, and 
always linked together. Itis probable that their 
separation takes place at a later season of the year, 
but I did not observe them in that state. The 
individual is amongst the most simple in shape of 
those yet described, presenting an oval-lanceolate 
and slightly rhomboidal flattened figure, without 
appendages. ‘The anal opening is of a bright 
brown hue, and circular, being placed at some 
distance from the extremity; and when the chain 
is linked together, all these apertures are directed 
the same way. ‘The animal is perfectly hyaline, 
and tender, and the adhesion of the chain so slight, 
that the individuals are easily separated. The act 
of swimming is known to result from the introduc- 
tion and emission of water by each animal: and as 
the republic swims together by an undulating 
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