160 LITTORINIDiE. 



Judging from tLis single specimen, a very distinct small 

 form. Sub-tuberculate above, striate [instead of sulcata] 

 below. Perhaps the form described by Smith, 1, c, as found by 

 Brazier at the Marshall Islands. 



var. [? dist. sp.]. 



Long. 3, diam. 2| mil. Differs from the Arakan form of 

 R. isseli by the still narrower pei'foration, more convex base, 

 with more regular and more numerous spiral sulcations. 



8 Cherboniane Reef ; coll. Dr. J, Armstrong. 



2 Mauritius ; ex c. Dr. F. Stolizcka [in bad condition ;' identification 



doubtful], 



var. subinfracostata [? dist. sp.]. 



Probably distinct ; the specimens have their opercula, but 

 are perhaps not quite adult ? Descr. de I'Egypte, PI. V, fig. 40, 

 gives a good idea of them. It is perhaps rather a var. of that 

 species, R. infracostata, Issel ? 



3 Nicobar Islands ; coll. Dr. F. Stoliczka. 



6. Risella [Peasiella] conoidalis. 



Trochus conoidalis. Pease, Amer. Journ. Conch. Ill, 1S67, Faumotus ; alt. 5, 

 diam. 4 mil. 



3 Faumotus [typical] ; coll. H. Pease, Esq. 



1. Risella [Peasiella] infracostata. 



Eisella infracostata, Issel, 31alac. Mar Eosso, 1864, Suez and Desc. de 

 I'Uc/i/pte, yl. V, jig. 40. 



■ 6 Massaua ; coll. Prof. A. Issel. 



Sent me as " Troch. sismondce, Iss.", probably a lapsus 

 calami ? I am inclined to believe it can only be separated from 

 the following as a variety ; my Aden specimens seem a fairly 

 intermediate form. 



8. Risella [Peasiella] isseli. 



Risella isseli, Semper, Issel, Malac. Mar Sosso, 1S64, Suez and Zinxi- 

 bar; Descr. de VEgypte, pi. V,Jig. 33, 



