﻿R I S S A. 



Platk XII. 



Species lOG. (Miis. Watson.) 



RissOA AUK.\NTIACA. Ris. testd paUklti aurantid, alia, 

 qn'rd siihquadratd; anfradihiis quinis, convezius- 

 culis, alti.'i, spiraliter tenuiter cmtatis, superne 

 costis ohliquis, siihdistantibus, longitudiiialihus, 

 sculqitts, ultimo anfradu infra spimliler conspicuu 

 hicoHato ; apcHurd ovatd, lahio Into, iiiarginc 

 intfiiio antico acute producto. 



Tee orangk RrssoA. Shell pale orange, raised, spire 

 a little in steps ; whorls five, rather convex, 

 spirally finely ribbed, sculptured above with 

 oblique, rather distant longitudinal ribs, last 

 whorl with two spiral ribs below ; ajierturo 

 ovate, liji broad, inner margin anteriorly sharply 

 produced. 



WAT.SON. Proc. Zool. Soc. 1873, p. 367, PI. XXXIV. 

 f. 3. 



Ilah. Madeira. 



Species 107. (Mus. Watson.) 



RissOA CElsi'A. Ill's, testd parvd, alhidd, undulatlm 

 sqnraliter costatd, gradaid, cosiis crassis loiigitudi- 

 nalihus fltimmsk oniatd; apice obtuso ; anfractibtcs 

 quaternis, supra medium angulatis, ultimo infra 

 spiraliter bicostato, umbilicato ; aperturd subtri- 

 gond, lahio crassc, extih nreiiato, xuprfl infraqne 

 angidatij. 



The crisp Rissoa. Shell small, whitish, spirally 

 ribbed in waves, ornamented with thick longi- 

 tudinal flexuous ribs ; apes obtuse ; whorls four, 

 angular above the middle, last with two spiral 

 ribs below, umbilicated ; aperture subtrigonal, 

 lip thick, crenated outside, angular above and 

 below. 



Watson. Proc. Zool. Soc. 1873, p. 3G',1, PI. XXXIV. 

 f. (1. 



TIab. Madeira. 



Species 108. (Mus. Marrat.) 



Rissoa iUcANDEEWI. Bk. testd pared, Ireui, rvhro- 



fuscd; anfradihus quinque, gradatis, angulatis, 



spiraliter crebre costatis, mstis perpendicularihus, 



crassis, supra medium angulatis munitis, ultimo 



infra spiraliter iniiroflato; ajKrl lira oblique siih- 

 ovatd ; costd labiali crassil, rotunda, spiiruUter 

 liratd. 



Macandrew's Rissoa. Shell small, short, reddish- 

 brown ; whorls five, in steps, angular, spirally 

 closely ribbed, strengthened with perpendicular 

 thick ribs, with an angle above the middle, last 

 with a single S])iral rib below ; aperture obliijuely 

 subovate, labial rib thick, rounded, spirally 

 ridged. 



Watson. Proc. Zool. Soc. 1873, p. 372, PL XXXIV. 

 f. 8. 



ITab. Gorgulho, Madeira. 



Species 109. (Mus. Waison.) 

 Rissoa MonizianA. L'is. testd brcvin<'cv,ld,fere albd, 

 spiraliter liratd, liris rotundis, approximatis ; apire 

 acuta; anfractibus quaternis, brembus, supra 

 medium, angulatis ; aperturd magna, rotundd, 

 costd labiali subexpansd, crassd. 

 MoNizi's Rissoa. Shell rather short, almost white, 

 spirally ridged, ridges rounded, close ; apex 

 acnte ; whorls four, short, angular above the 

 middle ; aperture large, rounded, labial rib rather 

 expanded, thick. 

 Watson. Proc. Zool. Soc. 1873, p. 30;i, PI. XXXIV. 



f. t;. 



Hal), iladeira. 



Species 110. (Mus. Watson.) 



Rissoa picta. Uw. testd parvd, trochiformi, distanter 

 spiraliter striata, maculis fuscis rquadratis in series 

 tres dispositis ornatd; anfractibus quinque, con- 

 vexis, ultimo magna; aperturd subtrigand, lahio 

 crasso ; cohimelld crassd, arcuatd. 



The tainted Rissoa. Shell small, top-shaped, dis- 

 tantly spirally striated, ornamented with brown 

 square sj)ots arranged in three rows ; whorls 

 five, convex, last large ; aperture subtrigonal, 

 lip thick ; columella thick, arched. 



Jeffreys. Brit. Moll. 



Eab. Madeira. 



A narrower shell than L'iysoa depicia, the whoi'ls 



being more elongated and distinct. 



