THE TANGANYIKA PROBLEM. 



245 



exactly as they are in Typhobia, the operculum even 

 showing once more the typical peculiarities of Typhobia 

 (compare figure on p. 222). The buccal mass and the 

 salivary glands, the anterior ganglia and the nerves all 

 present the same disposition and appearance as in Typhobia. 

 The teeth (Fig. 26) on the radula, however, are not like 

 those of any of the preceding forms, the elements forming a 

 new type of dentition which we shall meet with again in 

 several other halolimnic forms closely allied to Paramelania. 

 In the remainder of its visceral anatomy, in the character of 



Fig. 27. — Shell of Paramelania damoni (-f ^). 



the intestine, in the possession of an anterior stomachic 

 chamber and a crystalline style, Paramelania is in all 

 respects similar to Typhobia, but like Limnotrochus and 

 Chytra it does not appear to be viviparous. 



P. CRASSIGRANULATA, SMITH. 



This form is in all respects closely similar in the 

 structure of its soft parts, shell, operculum and radula, to 

 P. damoni. (See Figs. 25 and 26.) 



