OF THE MANDUCATORY ORGANS IN THE CLASS ROTIFERA. 
431 
52. The rami here take the form of moveable blades or jaws (figs. 16,21), which 
arch across the vault of the mastax towards the dorsum, and receive, on their convex 
surfaces, the unci, which are tied to them near their extremities. The rami are 
capable of being widely opened (fig. 21), when several jagged teeth are seen on their 
opposing edges, which lock into each other when closed. In the act of expansion, 
an obtusely pointed lamina is seen below their arch (fig. 21, r), which is capable of 
being slightly protruded or contracted, independently of the motion of the rami or 
unci. The rami themselves, though opened and closed with the mallei, are not 
dependent on the action of the latter, for they evidently possess a powerful sponta- 
neous motion in opening and closing. This movement is doubtless produced by the 
muscular bands which (as we saw in Euchlanis) connect the lateral processes {alulce) 
of the rami, which are greatly developed, with the fundus of the mastax, and with the 
foot of the fulcrum (t and u). 
53. The muscles of the malleus differ from those which we have seen in Brachionus 
and Euchlanis. A long band passes from the summit of the manubrium to the fun- 
dus of the mastax ; another ties its lower extremity to the paries, immediately below 
it ; while a third passes upward from the inner face of the same piece, probably to the 
inferior surface of the uncus (fig. 16). 
54. The entrance of the buccal funnel into the mastax is, in this species, protected 
by a vault of many complex pieces, which appear solid (fig. 16, v), though of such 
tenuity and fragility that I have not been able to resolve them satisfactorily. 
5l5. Notommata clavulata (figs. 22 to 26), a species of large size and of peculiar 
beauty, is remarkable for the great development of the mallei. The buccal funnel is 
here shallow, but richly ciliated ; its short tube merges insensibly into i\\e mastax 
(fig. 23), which consists of three lobes, more than usually marked, and nearly sphe- 
rical. Each manubrium is, as usual, dilated above, where the lateral loops are tri- 
gonal, and attenuated below. A broad trapezoidal uncus (figs. 25, 26) is articulated 
to it, of eight fingers, of which the second and third are branches of the first. The 
fingers are arched both transversely and longitudinally, and their extremities are con- 
nected by a web (fig. 26). A transverse process crosses their inferior surface, doubt- 
less a point of attachment to the ligament, which fastens them to the ramus of the 
incus, and which corresponds to the triangular ligament {i) described in Brachionus 
(§ 28). The elasticity of this ligament is well shown in the working of the jaws; for 
the uncus is elevated to a considerable distance above the level of the incus (see fig. 24), 
when the appearance and action of the pair are exactly those of curved dentate man- 
dibles, opening and snapping across the tube of the buccal funnel. The incus is 
placed nearly horizontally, or at right angles with the plane of the manubria; but, 
during the vigorous working of these organs, they are alternately depressed and ele- 
vated to so great a degree, that the fulcrum appears now above, now below their level. 
56. The fulcrum is rather short, much compressed, and thickened at its free extre- 
mity ; its direction scarcely deviates from that of the rami, — in this respect contrast- 
