162 LITTORINnXE. 



the suture ; undulately " waved " or subimbricate at the suture, 

 as in Descr. de 1'Egypte, PI. V, fig. 35, which indeed gives 

 perhaps a better idea of this Andaman species than of the 

 Red Sea form ; intermediate forms will probably occur to 

 connect the two ? 



4 Andamans ; coll. Capt. R. C. Temple. 



var. subimbricata. 



With the uniform yellowish coloration of the typical form 

 and the peculiar subimbricate sculpture at the sutures and 

 periphery of the preceding variety. 



6 Andamans ; coll. Capt. R. C. Temple. 

 11. Risella [Peasiella], n. sp. 



1 Muscat j coll. W. T. Blanf ord, Esq. 



A very small form, with peculiar, perfectly flattened spire ; 

 below the acute periphery there is a deep and broad sulcation, 

 the rest of the base appearing smooth, though under the lens 

 a minute striation can be detected. The umbilical perforation 

 is very small. 



Genus PHAKETA, H. Adams. 

 P. Zool. 8. 1870, type P. everetti, H. Adams [Siniwar Rv., Borneo]. 



The correct classification of this Genus appears to be still very 

 doubtful. Phaneta is not as yet represented in the Museum. 



Genus FOSSAE, Gray. 



Syn. J3rit. Mus. 1840, type Helix ambigua, Lin. ;=Fossarus, Philippi, 

 1841 ; sect.= Clathrella, Hecltiz, J. de C., XII, 1864, types Foss. 

 costatus, Srocchi, and Foss. minutus, Michaud. 



A. Adams figured a Fossar licarinatus in the P. Z. S. for 

 1853 from the Red Sea ; he describes the operculum as " horny, 

 oval and subspiral." 



l, Fossar ambiguus. 



Helix anibigua, Linnaeus, Syst. Nat. 1758, Mediterranean ;=" le Fossar,'' 

 Adanson, 1757, Senegal ;=Fossarus adansonii, Eecluz [? not of Phil. ,] 



