AND ALLIED FORMS. 37 



bates,^ Tjlanford. Unfortunately the lingual dentition of these 

 genera, which would afford us the best guide to their true position 

 in the system, has not yet been examined. They are all more or 

 less amphibious in habits, but their respiratory organs have not 

 been studied with sufficient care to determine whether they are 

 branch ifei'ous or pulmoniferous. If they breathe by means of 

 "lungs,"^ two of them must be referred, with Ibmichia, etc., to 

 the neighborhood of the Truncatellidfe, while the other will form 

 a new family. But if they are truly brauchiferous, they must be 

 closely related to the two subfamilies of Rissoids which have been 

 treated of above. 



Cecina and Blanfordia are both Mantchurian or Japanese 

 genera, found, like the Truncatellae, in damp places near the sea. 

 They have both, however, shells with olivaceous periostraca and 

 opercula similar to those of Pomatiopsis. In the first-mentioned 

 genus the eyes are also placed at the outer bases of the tentacles, 

 which would seem to exclude it from the Truncatellidae and 

 approximate it still more to Pomatiopsis ; but the tentacles are 

 said to be lobiform and flattened, and no mention is made of 

 sinuses in the sides of the foot. Further investigation of this 

 genus is therefore necessary before its true place can be determined. 



Blanfordia shows even greater resemblance to Pomatiopsis 

 than Cecina does, for we find in it the same arrangement of lobes 

 and sinuses in the sides of the foot, indicating the same stepping 

 mode of progression ; but this is accompanied by the Trunca- 

 telloid character of having the eyes on the upper bases of the 

 tentacles ; so that the genus will very probably be found to belong 

 to the Truncatellidce when its respiratory organs and dentition 

 are examined. 



Cremnobates is an East Indian genus, found on rocks wet by 

 fresh-wator. It is referred by Blanford to the LittorinidsB. It 

 has a trochiform shell very different from that of Cecina and 

 Blanfordia, and approaching that of the marine genus Fossarus. 

 There is said to be a " large vascular sac at the back of the neck." 

 The eyes are on the outer bases of the tentacles, and the foot is 

 not lobed. The operculum is subspiral and testaceous. The 



' Ann. cit. [3], XII, (1863,) 184, pi. iv, fig. 1-12. 



2 The intermediate type of breathing-organ found in the operculated 

 terrestrial Gasteropods, Cyclostoma, etc., is here meant. 



