1890.] MARINE MOLLUSCA OF ST. HELENA. 265 



Museum) ; Ascension Island {Conry) ; Cape Verde Islands {Mac- 

 Andrew). 



The specimens collected by Mr. Melliss at St. Helena and named by 

 Jeffreys P. rudolphi (Ann. & Mag. Nat. Hist. 1872, April, p. 264) 

 belong to this species. St. Helena examples are generally of a darker 

 colour than those from the West Indies, but they agree in nearly 

 always having a purple-brown stain on the edge of the columella 

 bordering the canal. This seems to be a fairly constant character. 

 Purpura forbesii, Dunker (Index Moll. Guinea, p. 22), is very close 

 to, if not the same as, this species. 



The shell described by Quoy and Gaimard is scarcely half-grown, 

 and has a very different appearance from the adult worn specimen 

 figured in the ' Conchologia Iconica ' as P. fasciata. The series of 

 specimens in the British Museum clearly shows, however, that both 

 are merely different stages of one and the same species. 



MiTRA (Cancilla) turtoni. (Plate XXII. fig. 1.) 



Testa fusiformis, dilute olivaceo-fusca, spiraliter crebre lirata et 

 sulcata, in sulcis longitudinaliter striata ; anfractus 10, apicales 

 ires aut quatuor Icevigati, pallidi, cceteri leviter convexi ; aper- 

 tura rubescens, longit. totius ^ cequans ; columella paulo obliqua, 

 plicis 4-5 in medio instructa. 

 Longit. 27 millim., diam. max. 8 ; apertura ISg longa, fere 



3 lata. 

 This species is considerably like M. gambiana, Dohrn, as regards 

 form, but differs in colour and sculpture, the sulci being deeper, 

 and the intervening lirse narrower. The fine longitudinal striae are 

 chiefly visible in the grooves, but they do to some extent cross 

 the riblets. 



MiTRA (Turricula) innotabilts. (Plate XXIII. fig. 9.) 



Testa parva, fusca, lira alba circa medium anfr. ultimi ornata ; 

 anfractus 6, nucleus magnus, convexus, nitidus, anfr. sequentes 

 paulo convexi, costis obliquis circa 12, lirisque spiralibus, supra 

 castas nudulosis (in anfr. superioribus 3, ultimo circiter 12) 

 instructi ; apertura angusta, longit. totius | hand cequans ; 

 columella triplicata, callo tenui amicta ; labrum tenue, intus 

 Iceve. 

 Longit. 7 millim., diam 2|. ; apertura 3 longa, 1 lata. 

 The cancellation is coarse for so small a shell. The whorls have 

 a slightly turreted appearance, being divided by a deep suture. The 

 white liration is the third from the top of the whorls. 



MiTRA (Pusia) sanct^-helen^. (Plate XXII. fig. 2.) 



Testa parva, brevis, ovata, alba, inter nodules nigro fasciata ; 

 anfractus 5, primus lavis, globosus, nigrescens, cesteri convexius- 

 culi, sutura subprofunda sejuncti, costis confertis, granulosis, 

 sulcis spiralibus sculptis instructi ; costce circiter 16, vix obliquce, 

 fere ad basim anfr. ultimi productce ; sulci angusti, subcequales, 

 in anfr. superioribus 2-3, in ultimo 10-12; apertura parva. 



