216 
CORRESPONDENCE. 
I presume is allied to your Bucephalus ; possibly not identical with 
it. I never found it /ree, but the individuals I found were remarkable 
for such rapid and sudden movements as were described in your 
animal. My short communication was written under the impression 
that the assertion of the non-parasitism of Bucephalus was not con- 
fined to your species or variety, whatever it is. I leave the matter 
in your hands, and remain, 
" Dear Sir, yours very faithfully, 
«R. Garner." 
With Mr. Garner's permission I now enclose copy of the figure 
in his paper.* In reference to it he says that he found it in the foot 
of an Anodonta, and that it presented the following characters, viz : 
" In the mature state the body is more or less cylindrical in its shape, 
but varied much at the will of the animal. At one extremity it has 
two very long appendages, which are spiniferous at their terminations, 
and which in some individuals have a row of round bodies attached 
to one side for part of their length ; these appendages are contracted 
with great rapidity, and are then very short. There is an opening by 
a circular lip between these appendages. A contraction separates 
this part, on which they are situated, from the rest of the body. 
There appears to be another opening at the opposite extremity of the 
animal." I think it will be seen from the above as compared with 
my animal, and also with the Bucephalus polymorpJius and Haimeanus, 
that although there is some resemblance in form and character, yet 
that it more nearly approaches the B. Haimeanus than either, and 
that all three differ very much from the creature I have found, and 
which so far remQ,ms unique. 
I remain your obedient servant, 
John Badcook. 
Eemarks on Crito's Letter. 
To the Editor of the ' Monthly Microscopical JournaV 
Dalston Vicarage, near Carlisle, 
September 11, 1875. 
Sir,— In " Crito's " letter, in the last number of the * M. M. J.' 
there are some passages which must, I conceive, excite surprise in the 
minds of many of your readers. 
Mr. Mayall had observed that, tried by the test of deep oculars, 
the image with certain specified comparatively low-angled objectives 
breaks up with any magnification beyond about 1000 diameters. In 
reply, " Crito " quotes the nominal linear magnifying powers of lenses 
of the same focal length as those referred to by Mr. Mayall, with 
different eye-pieces, as though that were a conclusive answer. But 
surely he forgets that the whole question at issue is not as to possible 
* [We have received a copy of the figures from Mr. Badcock, but as they have 
ahcfidy appeared elsewhere we think their reproduction here is unnecessary. — 
lOi).' M.M.J.'] 
