38 
Nore on Dr. Wautuicn’s Microscopic “ Jaw.” 
By G. Busx, F.R.S. 
In the October number of the ‘ Annals of Natural History’ 
(p. 304) is described and figured an organism contained in a 
muddy deposit dredged up at St. Helena, and regarded at 
that time by its discoverer, Dr. Wallich, as the lower jaw of 
a vertebrate animal, although, as he confesses, he had not 
then submitted it to any detailed examination. — 
The minute size, however, and general characters of the 
specimen, when it was exhibited at the meeting of the British 
Association at Cambridge, led many at once to doubt the 
propriety of this determination. Opinions, nevertheless, ap- 
pear to have been very widely divided as to the real nature 
of the object. Ina subsequent notice respecting it, in the 
December number of the same journal (p. 441), Dr. Wallich, 
in retracting his former opinion, as having been too hastily 
formed, states that the specimen had been pronounced by 
different observers to be—the mandible of a fish—a portion of 
the lingual ribbon of a Mitra—the claw of a minute crusta- 
cean—part of the manducatory apparatus of Notommaia or 
an allied species,—and lastly, a valve of the pedicellaria of some 
species of Echinus, in which last view he is himself now in- 
clined to agree. 
As it would appear, therefore, that there must be some- 
thing peculiar in a structure about which such diversity of 
views can be entertained; and as Dr. Wallich, in his latter 
communication, has cited me as the author of the last opi- 
nion in the above list, it may perhaps be interesting to some, 
that the grounds upon which it is formed should be stated. 
As none of the drawings hitherto given of the organism 
afford anything like a correct notion of its real appearance, 
I have had the accompanying figures prepared by an artist, 
wholly, I believe, unaware of the nature of the disputes about 
it, and whose representation, therefore, may be regarded as 
uninfluenced by any preconceived opinion. 
Of the various opposed views above enumerated, it appears 
to me, and will perhaps also appear to most others, that 
the only ones requiring serious consideration are that advo- 
cated by myself and that so ingeniously supported by Mr. C. 
Spence Bate, in the December number of the ‘Annals of 
Natural History’ (p. 440). That gentleman, whose opinion 
in such a matter, if he had had an opportunity of inspecting 
the specimen itself, would, of course, carry the very greatest 
