Tae ee On Synchxta Mordazx. 31 
muscular bulbs (Fig. 7, f, f) (like gums, as Gosse says) can be seen 
enveloping the joint (e). 
From the aperture in the mastax (Fig. 6, 7) a wide curved tubu- 
lar sort of passage leads to the cesophagus (Fig. 6, 7); and on focussing 
down to about the centre of the mastax the edges of the passage assume 
the curious shape drawn at m,m,m,m, Fig. 6. This outline en- 
closes the area (Fig. 6, &) which would be obtained by a plane section 
of the passage at right angles to the optical axis of the instrument 
at the focus of the objective : if a slice were cut off a hollow india- 
rubber ring, so as to expose the interior without cutting through 
the ring, a similar (though differently shaped) area would be 
produced. Inside the mastax is a very powerful V shaped muscle. 
It is striated ; and the striz produce the blue tint which is so often 
seen with oblique light on diatoms. The muscle embraces the lower 
end of the fulcrum, and by jerking it up and forward throws out the 
rami. The mallei are also worked by large muscles (Fig. 6, 1, 1) 
which bend round their lower ends and are attached to the mastax. 
Gosse speaks of muscles at the sides of the mastax “lining the 
globosity of each lateral lobe.” I have tried every species of illumi- 
nation, and every artifice I could think of, but have always failed to 
see them. 
The whole apparatus is calculated to enable Synchata to sud- 
denly swallow large objects; and although I have never had the good 
fortune to see it, I suspect that Synchxta swallows whole, or nearly 
so, the smaller specimens of Spherostra, of the remains of which 
apparently its stomach was frequently full. 
The rami with their connecting membrane would arrest the globe 
as it was carried over the mouth by the ciliary currents, and the 
sharp points of the mallei would pierce it and drag it down. 
The cesophagus (Figs. 1, d, and 6,7) is very long and flexible ; 
usually the food passes through it direct to the stomach ; but S. mor- 
daz has a trick of occasionally throwing the contents of the stomach 
into the cesophagus, or of dilating it with water. The usual gastric 
glands are on either side of the stomach (Fig. 1, e, e), and there is 
nothing peculiar either in them or in the ovary (9), or the contractile 
vesicle (2). The arrangement of the tubes (f,f) carrying the pul- 
satile tags (k,/) is unusual. In most of the free-swimming rotifers 
the tubes pass up each side of the body from the contractile vesicle to 
the head; but in Syncheta mordaz they barely reach half-way, while 
branches of them, or of something like them, can be traced half across 
the gastric glands. 
To the vexed question of the pulsatile tags, I should like to 
contribute a suggestion. I quite agree with Mr. Cubitt in doubting 
the existence of any cilia in them, for in some positions (especially 
in the case of Huchlanis) they present different appearances, as in 
Fig. 10. 
