214 Transactions of the Eoyal Microscopical Society. 
III . — The Building Apparatus of Melicerta r ingens.* 
By Francis Alfred Bedwell, M.A., F.R.M.S. 
{Read before the Royal Microscopical Society, November 7, 1877.) 
Plates CXCYII. and CXCVIII. 
The long-continued absence of Mr. Cubitt’s interesting papers on 
this subject, has induced me to group together the following parti- 
culars, which are the results of observations made by me in the 
years 1861-62. 
The building apparatus in M. ringens consists of a combination 
of very various parts, in which combination the pellet organ is but 
one item. It is requisite that the pellet should he specific in 
shape when made, and in situation and in attitude when laid ; 
the materials have to be specifically selected, then- safe arrival at 
DESCRIPTION OF PLATES. 
Plate CXCYII. 
A. — An attempt to represent M. ringens in a natural attitude ; tlie fourth lobe 
is hidden from view. The increase in the diameter of the case is due to the 
growth of the animal, which simply makes larger pellets as it grows older. 
B. — Diagrammatic figure exhibiling progress of material collected by J/. ringens 
from the moment of its reaching the lobes, and showing its division into ‘‘eat- 
able,” “ mural,” and “ waste ” streams ; its passage down the secondary lips past 
the first tasting organs (represented by two triangles) to the reflecting cushion 
(represented by the cubical figure), and thence to the mastax on the one hand, 
and the side chins and pellet organ on the other, giving also the tasting organs 
immediately above the mastax (represented by two triangles) and the pellet 
organs with pellet, together with the set® armed pimple that decides the position 
of the pellet and the movable projection below the pellet organ, which with the 
main chin pinches and actually deposits the pellets. The hooks or spines and 
the long antennse are omitted. 
Plate CXCVIII. 
Figs. 1, 2, and 3. — Mechanical illustrations of collecting apparatus of Rotifers, 
exhibiting the transition from forms like Melicerta to Conochilus (see text). 
Fig. 4. — i, b, c, d. and e are five successive diagrammatic transverse sections 
showing sectional limits of sinus as seen by an eye looking directly over the 
main chin into the pellet organ and focussing upwards, bringing out the curled 
or bent edge of the sinus projecting over the ditch of cilia leading by side chins 
to pellet organ (see text). 
Fig. 5. — Diagram illustrating extraordinary method in which pellet is some- 
times constructed. The arrow denotes the side chin along which the accession of 
mural particles is not stopped (see text). 
Fig. 6. — Outline view of M. ringens ascending from tube, and showing pimple 
of set®. 
Fig. 7. — Outline view of Limnias ceratophydi ; ( a , b) is the line of the shield- 
like organ. 
Fig. 8. — Front view of shield of L. ceratophylli ; (a, b ) as in previous figure. 
* The papers referred to are the following : — Mr. Cubitt’s, ‘ M. M. J.,’ vol. iii. 
p. 240 ; * M. M. J.,’ vol. v. pp. 168 and 205 ; ‘ M. M. J.,’ vol. vi. p. 165 ; ‘ M. M. J ,’ 
vol. viii. p. 5. Dr. C. T. Hudson, 1 M. M. J.,’ vol. xiv. pp. 225 and 267. Mr. 
Henry Davis, ‘M. M. J.,’ vol. xvi. p. 1. 
