440 MR. P. H. GOSSE ON THE STRUCTURE, FUNCTIONS, AND HOMOLOGIES 
101. Professor Ehre.nberg had simply described the apparatus as consisting of 
teeth, which, like the arrow on a bow, are fastened across the jaw* ; and M. Du- 
JARDIN does little more than repeat the description. He says, “ all these animals 
present a pair of jaws, almost in form of a stirrup, composed of an arch traversed by 
a bar, on which lean, by the free extremity, three parallel teeth springing from the 
bow of the stirrup, which is engaged in the fleshy bulb'f'.” 
102. Di’.Leydig, who complains of the inaccuracy of Ehrenberg’s figures, describes 
the apparatus as consisting of “ two bent quadrangular plates, across which several 
lines are stretched ; the three foremost, which are stouter than the rest, jutting out 
as three teeth.” He says that the two plates have a shears-like figure ; and notices 
at their union ‘‘an apophysis {Xha fulcrum) , which seems to enter into the circular 
mass of the gizzard :J;.” 
103. Mr. Huxley, on the other hand, saw the analogy of this type with that which 
I have already considered ; but not with the stirrup-like form which is found in 
Philodina, &c. He thus describes it : “ The armature of the pharyngeal bulb 
is composed of four separate pieces. Two of these (which form the incus of Mr. Gosse) 
are elongated triangular prisms, applied together by their flat inner faces§: the 
upper faces are rather concave, while the outer faces are convex ; and upon these 
the two other pieces (the mallei of Mr. Gosse) are articulated. The last are elongated 
— concave internally, convex externally — and present two clear spaces in their 
interior; from their inner surface a thin curved plate projects inwards. At its 
anterior extremity this plate is brownish, and divided into five or six hard teeth, with 
slightly enlarged extremities. Posteriorly the divisions become less and less distinct, 
and the plate takes quite the appearance of the rest of the piece. 
“ This is essentially the same structure as that of the teeth of Notommata 
[^=.Asplanchna~\, described by Mr. Dalrymple, and by Mr. Gosse (on the anatomy 
of Notommata aurita) ; and verp different from the true ‘stirrup-shaped' arma- 
ture'.' 
104. Professor Williamson describes the apparatus with elaborate care as he finds 
it in Melicerta. His remarks are too long to quote, but they agree mainly with 
what was already known. He notices “two broad elongated plates,” which he calls 
“crushers^' from which “proceed laterally numerous parallel bars, somewhat thick- 
ened at their inner extremities, where they are attached to the plates ; whilst at their 
opposite ends they are united with others of the same side by a curved connecting bar, 
from the outer sides of which are given off various loops and processes. . . . From the 
upper extremities of the two crushers there project, upwards and backwards, two 
slender prolongations, united by a kind of double hinge-joint near their apex, where 
they not only play upon each other, but also on a third small central fixed point, 
* Infusionsth. p. 386. f Ibid. p. 615. t Sieb. and Koll. Zeitsch. 1852, p. 463. 
§ Mr. Huxley says, these are “ not described byLEYDio;” but they are his “bent quadrangular plates,” ut 
supra. 
