Mastax M. ringens, &c. Lord S. G. Osborne and F. A. Bedwell. 183 
rectangular aspect, and whicli views I derived solely from Lord 
Sydney G. Osborne's slides, and I must still attribute that aspect to 
the pressure of the free edge of what I have called the central blade 
of the ramus acting on the under side of the teeth, that free edge 
being forced up by the pressure on the alulse. A fact to be borne 
in mind is, that in the dead Conochilus and Melicerta ringens 
pressure usually severs the alulse from the propelling arms of the 
spur at the point c, where I have severed them in the drawings, 
and the consequence is that in all the mounted specimens there 
is little to indicate at these angles any solid attachment to the 
alidae or the existence of a propelling force in connection with 
them. In some specimens of Melicerta, however, from Kedditch, 
Lord S. G. Osborne has sent me mountings in which I think this 
connection is sustained; these Melicerta from Redditch are also 
remarkable for Mr. Slack’s conical pellets; some are actually true 
cones, and others are so long that they are more like ninepins than 
rifle bullets ; they are also remarkable for javelin-headed teeth. 
To make out the points here detailed in Conochilus I found it 
necessary to study it alive and dead. It is a most convenient 
animal to manipulate, it cannot get away, and it gives you ten 
or more specimens in each group, ^ in various attitudes. You 
must gently clean it from debris with two fine needles. Dead 
specimens should be treated as suggested by Mr. Gosse in his 
paper {1. c.) with potash and water ; with some specimens half and 
half is too strong, with some it is not strong enough. 
As mentioned by Mr. Davis, t the red spots (two in number) 
are in Conochilus most remarkable organs ; each has a highly re- 
fractive hemisphere resting on the flat red disk, and apparently 
partially sunk into it ; as Mr. Davis has not drawn it, I have done 
so (see Fig. 12). The young female Conochilus is born alive; the 
jaws work in its mother’s womb. It comes into the world with a 
lump of transparent jelly attached to its foot, which goes to 
augment the globular store of material which is the pedestal or 
home of the colony. 
Everyone must agree with Mr. Davis in thinking that the 
disk of Conochilus is a very strange apparent departure from 
the ordinary run of rotifer disks. I give a diagrammatic form, 
Fig. 13, of the disk, which is corrected from that given by me in 
the eighteenth vol. of the ‘ M. M. J.,’ p. 214, in which I made an 
* The method I adopted with both Melicerta and Conochilus was to lay them 
under a piece of microscopic glass on a plain slide, with a very little cotton wool 
to ease the pressure. Under a low power I then pressed them until the mastax 
was separated or in the right position ; then by adding the liquor potassre stronger 
and stronger (and capillary attraction with blotting paper draws it under the 
glass), the body of the animal is dissolved and the mastax left free for examina- 
tion under high power. 
t ‘M. M. J.,’ vol. xvi. p. 1. 
