Anatomy of Paludestrina jenkinsi. 427 
dissecting out the two cartilages it is rather difficult to be 
certain as to the exact position the latter occupy. They 
are rather irregular, thick, flattish plates, the ventral 
edges of which are flanged outwards both anteriorly and 
laterally. They are loosely united in the median line ante- 
riorly and dorsally, and diverge ventrally and posteriorly. 
When separated out they appear to be rather asymmetrical. 
The finer structure is as described by Henking, except that it 
is doubtful whether the dark pigment referred to for ulve is 
present in jenkins?. 
The radula has been figured and described by Woodward 
(14), and that of P. ulve by Lehmann (6) and Meyer and 
Mobius (7). 
The anterior part of the cesophagus is very much folded 
dorsally. This folded condition is found in ulve, but it is very 
much more marked in the present species, the roof of the 
cesophagus being divided into three main divisions, each of 
which again exhibits lateral diverticula (Pl. XV. fig. 2). 
The stomach is a fairly large organ of irregular size, 
situated mainly in the body-whorl. For the most part it is 
thin-walled. It is lined with a relatively thick cuticle, which 
is apparently confined to the stomach and does not extend 
down. the intestine as it does in some other forms. 
On the average, the cells giving rise to this cuticle approxi- 
mate in size to those figured for Valvata piscinalis by 
Bernard (5), though they do not appear to be so regular 
(Pl. XV. fig. 4). It is interesting to compare the stomach- 
epithelia of these two forms with that figured by Randles 
(11) for Zrochus. It may be pointed out, however, that in 
certain areas just below tie cuticle a layer of (sc.) pigment- 
granules was found (cf. Randles, J. ¢.). 
Anteriorly the stomach gives off a large sac for the reception 
of the crystalline style, and parallel to this and opening into 
the stomach in the same plane is a well-marked pylorus, from 
the anterior extremity of which the intestine is given off. 
The pylorus and style-sac are in communication with each 
other by a narrow slit extending down nearly the whole of 
their length. This arrangement appears to be rather un- 
common, and the author has not succeeded in finding any 
cases exactly analogous among other Tenioglossa. The 
internal (right-hand) wall of the posterior chamber of the 
stomach shows a well-marked ridge such as is found in other 
Teenioglossa, and the aperture of the style-sac and pylorus is 
marked by a strong annular development of cuticle. <A 
localized patch of ridges is found in the neighbourhood of 
the entrance of the hepatic duct. Possibly these may be 
compared to the “ bosselures et sillons’’ described by Garnault 
