84 
Dr Fleming on the Natural History 
communicated specimens of tins zoophyte to my scientific 
friend and correspondent, Mr Montagu, he recognised it as 
a species which he had found on the shores of DevonshirCy 
and on which he was disposed to bestow the trivial name du- 
wio,^.-~But I cannot, at present, enter into the details of the 
history of this or other new species, having already wandered 
far from the object of the present communication, in which I pro- 
posed to myself to give a description of the Sertularia gelati- 
nosa of Pallas, with some remarks on its history and economy. 
S. gelatinosa. Stem composed of tubes ; branches in pairs, 
divaricate, sub-alternate ; denticles on foot-stalks, alternate, 
bell-shaped. 
Corallina hhformis ramosa pedunculls calyculorum contortis, 
Ellis’s Corallines, p. 23. Tab, xii. f. c. C., Tab. xxxviii. 
f. 3. B, C, B. 
Sertularia gelatinosa. Pallas, Elenchus Zoophytorum, p. 116. 
No. 67. 
The base of this Sertularia, by which it adheres to stones, is 
spreading, and spongy, and consists of numerous closely inter- 
woven tubular fibres, which rapidly approach to form the stem. 
The stem rises to nearly a foot in height, and is so flexible as 
to move with every agitation of the water. It is thickest at the 
base, w here it consists of numerous tubes ; but as these dimi- 
nish in number, until, at the top, there can only be perceived 
a single branched thread, it tapers gradually to a point. It is 
nearly straight throughout, and is seldom divided. 
The branches are disposed round the stem in nearly an alter- 
nate order, and as they are longest towards the base, and gradually 
diminish in lengtli towards the summit, a graceful tapering out- 
line is produced. They occur in pairs, which have their origin 
nearly at the same point. They are not formed from the ex- 
ternal tubes, as in some of the other Sertularim with compound 
stems, but from the central ones, those at the surface turning 
aside to admit their exit. These branches proceed from the 
stem in nearly a perpendicular direction, and diverge from each 
other at an angle of about 45°. Each branch is acutely coni- 
cal, giving out, towards the base, subordinate branches, likewise 
in pairs, similar to those on the main stem ; at last these bes- 
come alternate, and, gradually shortening, the subordinate stem 
supports only alternate denticles, and either terminates in twin 
