LITTORINID^]. 157 



These last agree well with Indian Ocean specimens ; they 

 measure long. 12|, diam. 8 mil. ; the sculpture oftentimes 

 becomes subobsolete, and the length of the spire varies in 

 specimens from the same locality. 



Sub-Genus ECHINELLA, Swainson. 

 Treat. Malac., 1840, type E. coronaria, Lamarck. 



62. Littorina (Echinella) cumingi. 



Trochus cumingi, Philippi, P. Zool. S., 1845, Guimaras (erron. ?). 

 3 Roratonga ; coll. H. Pease, Esq. 



63. Littorina (Echinella) coronaria [?] 



Monodonta coronaria, Lamarck, Hist., 1822, Hab. ? ; Lord Hood's Island, 

 fide Owning ; Hervey Island, in Cat. Mus. Godejfroy. 



5 Roratonga ; coll. H. Pease, Esq., and Asiatic Soc., Bengal. 



These all agree best with Philippi's figures 2 and 6 of PL II, 

 said to be L. bullata, Martyn, from N. Zealand [=L. papillosa, 

 Lam.] ; I preserve as above, however, the name under which 

 they were sent me by Mr. Pease ; from von Marten's remarks in 

 the Donum Bism., the distinctiveness of the two forms appears 

 to be very doubtful. Philippi gives as localities for L. bullata 

 Zanzibar and Swan Point [Australia]. 



Genus LIMN TROCHUS, E. A. Smith. 

 Ann. Mag. 1880, type L. IcirJci, Smith. 



E. A. Smith describes the operculum of Limn, thomsoni 

 as" horny, paucispiral and littorinoid. " 



1. Limnotrochus kirkii. 



Liinnotrochus kirkii, S. A. Smith, Ann. Mag., 1880, Lake Tanganyika. 



I Lake Tanganyika [typical] ; ex Mr. Damon. 



Genus PLESIOTKOCHUS, Fischer. 

 J. de C., 1878, type P. sourerbianu.*, Fischer [Loyalty /.]. 



