ee 
57 
keep afemale back a fortnight later, he doubted not he might have 
brought up nearly a hundred males of B. Quercus, drawn by a sense 
either of smell of a very acute character, the organ of which had not 
yet been satisfactorily pointed out, or by some sense, not yet localized 
or named by the naturalist. 
The point had not been cleared up earlier simply, because, relying 
on some of the points of difference before mentioned, no one, as far as 
he knew, had kept back northern females and tried the experiment of 
seeing whether they would attract southern males. 
The Paper was illustrated by specimens of both insects, 
In the discussion which ensued, in which Messrs. Hollis, Hennah, 
Sewell, Nichols, and Dr. Hallifax took part, it was considered that the 
slight differences were not sufficient to constitute a species, while ex- 
amples where given showing far greater variation in some of the sup- 
posed distinctions, and which were owing to climate or food. 
Mr. Sewett brought forward, at the request of Mr. Robertson, some 
specimens found by that gentleman the preceding Saturday. He went 
to Rottingdean to get specimens of pholades on which to make experi- 
ments and observations, but found they were nearly exterminated. He 
was informed that they were taken out with pickaxes for bait. 
Mr. Expnick exhibited a specimen of calcareous spar, from 
Berwick, obtained near the top of the hill in the chalk, 
Aveust 247TH, 
MICROSCOPICAL MEETING.—DR. HALLIFAX ON 
“ POLYZOA.” 
The term Polyzoa was applied to certain animal forms (mostly micro- 
scopic) which, from their zoophytic external character and mode of 
growth, were formerly grouped indiscriminately with the zoophytes ; 
from a better knowledge, however, of their internal structure, they were 
now placed at the bottom of the Molluscan series. 
