ORDER BRANCH1 OPOD A. 
341 
which he names the posterior lobule of the labrum. Im- 
mediately underneath are two mandibles, (interior jaws, 
Ramdohr), very strong, without palpi, directed vertically, 
and applied on two horizontal jaws, (external jaws, Ramdohr), 
terminated by three robust corneous spines, in the form of 
curved hooks. Then come ten feet, all having the second 
articulation vesicular; the first eight are terminated by an ex- 
pansion in the form of a fin, furnished on its edges with seta) 
or barbed filaments, disposed in the manner of a crown or 
comb ; the two anterior appear more especially adapted 
for prehension. Accordingly, M. Ramdohr takes them for 
double palpi (internal and external). These are the same 
pieces that J urine elsewhere calls hands. In the figure which 
he has given of them, the terminal seta) appear to be barbed. 
We do not see why these appendages might not serve for 
respiration, a property which M. Straus grants only to the fol- 
lowing, because these latter have, in addition, a lamina on the 
internal side, which, with the exception of the last two, is 
bordered with a range of seta), in the manner of a comb, and 
equally barbed, to judge from the figures given by Jurine and 
M. Ramdohr. The last two feet have a structure a little diffe- 
rent, and M. Ramdohr distinguishes them under the name of 
claws. The abdomen, or the body properly so called, is 
divided into eight segments, perfectly free between its valves, 
narrow, elongated, curved underneath at its extremity, and 
terminated by two small hooks turned backwards. The sixth 
segment presents, on its upper part, a range of four nipples, 
forming denticulations, and the fourth, a sort of tail. The 
ovaries are placed along the sides, between this segment and 
the first, and open separately near the back, into a cavity 
(matrix, Jurine), situated between the shell and the body, 
where the eggs remain for some time after being laid. 
Muller has given the name of ephippium or saddle to a 
large, obscure, and rectangular spot, which at certain periods 
