554 MB. E. A. SMITH ON MARIKE SHELLS 



wborls are smooth, whilst in the latter six are sculptureless. The 

 ribs of the Solomon-Islands examples are rather fewer, and the 

 whole shell is a trifle larger. 



&]. RiSSOINA TEREBROIDES, Sp. nOV. PI. XXX. fig. 19. 



Testa breviter subulata, solidiuscula, albida, cii'ca medium anfractuum 

 fusco zonata et supra partem infraraedianam fusco tincta ; anfractus 

 10? apicales abrupti, reliqui 7 convexiusculi, costis obliquis 11-12 

 mediocriter crassis, leviter areuatis instructi, ubique minutissime spi- 

 raliter striati; anfr. ultimus infra medium longe crassius striatus, 

 costas baud ad basim productas gerens ; apertura parva obliqua alba j 

 labrum extra fortiter et late varicosum ; columella obliqua, leviter 

 arcaata, callo teniii induta; canalis baud profundus sed distinctus. 

 Long. 8| mill., diam. 2§. 

 Hab. San Christoval, Solomon Islands. 



The shortly snbulate form, the stoutish oblique ribs, the most 

 minute spiral striation and the much coarser striae around the 

 base of the last whorl, and the style of colouring are the chief 

 characteristics of this species, 



68. Cerithium coLUMNA, Sowerby, * Genera of shells' No. 42, f. 7; 

 Thesaurus Conch, ii. pi. 178, f. 56-58 ; Reeve, Conch. Icon. xv. f. 2, 

 a, b. 



Hab. San Christoval, Solomon Islands (Brazier) ; Philippine Islands 

 ( Cuming) . 



69. C. ARMATUM, Pkilippi, Abbild.u. Beschr. Conchylien, vol. iii. pl.i. 

 f. 9 ; Sowerby, Thesaurus, ii. pi. 1 79. f. 68 ; Reeve, Conch. Icon. xv. 

 f. 14, a, b. 



Hab. San Christoval, Solomon Islands {Brazier) ; Philippine Islands 

 {Cunning). 



70. 0. PLANUM, Anton, Philippi, Abbild. und Beschreib. Conchyl. iii. 

 p. 19, pi. i. f. 18 5 Sowerby, Thesaurus Conch, ii. pi. 181. f. 111-113; 

 Reeve, Conch. Ic. xv. f. 79. — Var. = C. balteatum (Philippi?), Sowerby, 

 I. c. f. 116, 117; Reeve, f. 72, a, b. 



Hab. San Christoval, Solomon Islands (Brazier) ; Philippine Islands 

 (Cuming). 



The chief difference between this species and the variety ialfe- 

 atum is, that it is rather smoother, and rather more deeply pitted 

 between the longitudinal costations. Both forms have the black 

 apex and the orange or brown base, halteatum having a band at 

 the base of the upper whorls, which passes round the last one a 

 little above the middle. This zone is not present in the typical 

 planum ; but there are three specimens of a variety of it in the 



