Anatomy 0/ Paludestriua jeiikinsi. 427 



(lissectiiiff out the tu'o carfilaires it is rather difficult to be 

 certain as to the exaet position the Latter occupy. They 

 are rather irregular, tiiick, flatfish plates, the ventral 

 edges of which are flanged outwards both anteriorly and 

 laterally. Tiiey are loosely united in the median line ante- 

 riorly and dorsally, and diverge ventrally and posteriorly. 

 Wiien 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 ulvce is 

 present in jenklnsi. 



The radida has been figured and described by Woodward 

 (14), and that of P. ulvce by Lehmann (6) and Meyer and 

 Mobius (7). 



The anterior part of the oesophagus is very much folded 

 dorsally. This folded condition is found in ulvcv, but it is very 

 much more marked in the present species, the roof of the 

 oesophagus being divided into three main divisions, eacii of 

 which again exhibits lateral diverticula (PI. 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 (/), though they do not appear to be so regular 

 (PI. XV. fig. 4). It is interesting to compare the stomach- 

 epithelia of these two forms with that figured by Handles 

 (11) for Trochus. It may be pointed out, however, that in 

 certain areas just below tiie cuticle a layer of {sc.) pigment- 

 granules was found ((/. Randies, /. c). 



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 st}le-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 .-ucceedc.d in finding any 

 cases exactly analogous among other Tienioglossa. The 

 internal (right-hand) wall of the posterior chamber of the 

 stomach shows a well-marked ridge such as is found in otlK-r 

 Taiuioglossa, and tiie aperlure of the style-sac and pylorus is 

 !narked ijy 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 " bosselureset sillons" described by Grarnault 



