82 Dr. H. Fol on the Family 'Tintinnodea. 
regular and are placed very close together. A single nucleus 
in the posterior part of the body. Vibratile lamelle of the 
peristome broad, and followed by a considerable number of 
independent cilia. A circlet of cilia outside the cirelet of 
undulatory lamellee. 
Tintinnus ampulla, auctt. (PI. IV. fig. 7.) 
The inner lamina of the test forms two circular folds at the 
part where the contours change their direction. The undu- 
latory lamelle are more powerful in this species than in any 
of those which I have observed. ‘he vibratile cilia which 
are implanted in the walls of the cesophagus are particularly 
powerful and easy to see. The test measures 0°11 millim., in 
Jength and 0-1 millim. in breadth. The numbers previously 
given were erroneous. 
Tintinnus spiralis, auctt. 
The dimensions that I have indicated for the test in my 
previous article were not correct, in consequence of an error in 
the calculation of the magnifying-power. The length of the 
test is only 0°312 millim. instead of 0-4 millim., and its width 
at the aperture is 0°068 millim. instead of 0:09 millim. 
The two lamelle of the test are perfectly distinct and 
united to each other by somewhat irregular septa, which, 
however, are in general directed from the front backwards with 
a spiral twist. It is these septa that I formerly described as 
simple striz. Between the septa there are longitudinal rows 
of small points, which are only the optical sections of small 
pillars passing from one lamina to the other. At the free 
margin of the test the two lamin separate a little from one 
another, thus leaving between them a wider space than else- 
where. Externally the margin of the test is enlarged into a 
sort of rib, while internally it is regularly cylindrical. The 
hollow rib is therefore formed by the separation of the outer 
lamina. The margin itself is hollowed by a furrow produced 
by a folding of the wall of the test at the spot where the outer 
lamina passes into the inner one ; this circular fold therefore 
projects into the cavity of the rib, which it diminishes to this 
extent. 
The peristome bears a circlet of undulatory palettes, which 
I formerly took for isolated cilia. Outside of these palettes it 
appeared to me that there was only one independent cilium to 
each spiral series; while within there are several cilia gradu- 
ally becoming shorter. My specimens, fixed by perchloride 
of iron and coloured by gallic acid, present a single oval 
