| OCR Text |
Show 1890.] MARINE MOLLUSCA OF ST. HELENA. 265 Museum) ; Ascension Island (Conry) ; Cape Verde Islands 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 sulcata, in sulcis longitudinaliter striata ; anfractus 10, apicales tres aut quatuor Icevigati, pallidi, cceteri leviter convexi; apertura rubescens, longit. totius \ cequans ; columella paulo obliqua, plicis 4-5 in medio instructa. Longit. 27 millim., diam. max. 8 ; apertura 13| 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 lirae narrower. The fine longitudinal striae are chiefly visible in the grooves, but they do to some extent cross the riblets. MITRA (TURRICULA) INNOTABILIS. (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, costas nudulosis (in anfr. superioribus 3, ultimo circiter 12) instructi; apertura angusta, longit. totius g haud 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.E-HELEN_E. (Plate XXII. fig. 2.) Testa parva, brevis, ovata, alba, inter nodulos nigro fasciata ; anfractus 5, primus Icevis, globosus, nigrescens, cmteri convexiusculi, sutura subprofunda sejuncti, costis confertis, granulosis, sulcis spiralibus sculptis instructi; costae circiter 16, vix obliquce, fere ad basim anfr. ultimi productce; sulci angusti, subcequales, in anfr. superioribus 2-3, in ultimo 10-12; apertura parva, |
