guard over them with a very pugnacious spirit; and he also 
detailed some curious observations upon the mode in which 
eels got large masses of food into their bodies. 
Mr. T. Gkaham Ponton then read a paper on the " Func- 
tions of the foot of the Conchifera, or biv^alve Mollusca," 
which might be conveniently considered under four heads : 
its use in locomotion, in burrowing and excavating, in the 
formation of byssus, and as the seat of the organ of hearing. 
Many bivalves not only moved slowly, but, as the cockle and 
Trigonia, were even able to jump by bending the foot. The 
second function, boring, had only been lately understood. 
Manj' molluscs buried themselves as a protection from their 
enemies; the Solen, or razor-tish, for example, by planting 
the foot on the sand, and then rapidly rotating, going down 
several feet. The Pholas was a very common English 
example of the boring mollusc; the wonderful effects of 
which had once been attributed to the agency of an acid 
secreted by the animal, to which theory, as to others, there 
were many objections. It was now generally acknowledged 
that the work was done by a rotatory motion, combined 
with a process of rasping and removal of the particles rubbed 
off, the requirements for all which processes were beautifully 
provided for. The foot was exceedingly elastic, owing to 
the presence of a special organ, the hyiline stylite, and, as 
well as the mantle and valves, very moveable, certain 
spoon-like processes, acting as levers, penetrating into the 
muscles of the mantle and foot. In the rasping, the foot, 
firmly pressed against the substance to be perforated, acted 
as a fulcrum to the valves of the shell, which rotated, and 
when a number of particles had accumulated, the foot sud- 
denly swelled and ejected them with water through the 
syphons. The next function, formation cf byssus, though 
the most important as far as man was concerned, was 
but little understood. In England the theory most usually 
received taught that byssus was the result of a peculiar 
exudation secreted by a special gland, the locality of which 
was variously stated. The author had made some experi- 
ments upon the common edible mussel: cutting away the 
byssus, he observed that threads were formed by the contact 
with and sudden withdrawal of the foot from the glass in 
which the animal w^s confined. Close examination of the 
foot revealed a groove along the base, which served to give 
form to the threads, and round this groove a glandular 
structure considered by Rhymer Jones to secrete the mate- 
rial of which the byssus was formed, an opinion confirmed 
by Mr. Leipner and Dr. H. Fripp. Mr. Ponton had examined 
the secretion chemically, and found it to resemble in its 
reactions keratine, a substance found in horn, nail, &c. The 
last function of the foot, its being the auditory organ, had 
been first clearly established by Von Siebold, in Cyclas, and 
since proved to exist in many other genera. Compression 
of the foot gave evidence of a ganglion, on both sides of the 
atoterior end of which was a small roundish cjst, with a 
vibrating body, like the otoliths of the higher animals, the 
receptacle corresponding to the vestibulum membranaceura, 
Mr. Ponton illustrated his paper with a series of beauliful 
drawings, as well as living specimens and dissections of the 
molluscs referred to, procured from Tenby. 
A slight discussion ensued upon the use of the byssus, and 
Mr. Leipner described somewhat in greater detail the struc- 
ture of the byssal threads. The president, in thanking Mr. 
Ponton for his valuable and interesting communication, 
observed that though very short, it contained a mass of 
information and investigation which might be truly called 
profound, and was highly creditable to him. 
WM. LANT CARPENTER, 
Honorary Reporting Secretary. 
