﻿R I S S A, 



Species 96. (Mas. Brit.) 



BlSSOA (oina) SULCIFEKa. Eis. testa crassa, palliJa, 

 pyramidatd ; aiifradlhus senis, spiraUter coslati's, 

 costis crassis, angulatls, supra sutiiram irihu.<, 

 iiilerdit'ds serrato-foveolatis ; ultimo anfradu siib- 

 reiitricoso ; aperturd pijriformi, labia extcriw 

 crasso, columelld crassd, siihplanidatd. 



The ciuoovKD Rissoa. Shell thick, pale, pyramidal ; 

 whorls six, spirally ribbed, ribs thick, angular, 

 tliree above the suture, interstices serrated in 

 pits ; last whorl subventricose ; aperture pyri- 

 form, outer lip thick, colnmella thick, somewhat 

 flattened. 



Troschel. ? .MS. Brit. :\Ius. 



llab. Coast of Belgium. 



Of a pale coloni', more broadly pyramidal than 



Fis.<oina Troch learis. 



tudlnal ribs, the last spinilly libbi'd in the middle. 



the longitudinal ribs ending; aperture small. 



somewhat pyriform ; columella straight below. 

 Goi-LD. Smithsonian Catalogue. 

 Jliib. Loochoo. 



Ju tlie middle of t lie last whorl the longitudinal 

 ribs cease, and the lower part is only riblied spirally. 



Species 97. (Mus. Brit.) 



lllssOA (oina) FLExnoSA. Eis. testd pyramidatd, ani- 

 minatd, medio spirce subconcavd ; coslis lunijitudi- 

 nalibus. supra viedixitn, angulatis spiraliter snbno- 

 dosis munitd ; aperturd brevi, subovatd ; lahio 

 interno superne .mbcalloso, coluiiidld aciifd ; labin 

 e.eferno iiifi's tuniido. 



The FLExnous Rissoa. Shell pyramidal, acuminated, 

 rather concave in the middle of the spire ; pro- 

 vided with few longitudinal ribs, angular above 

 the middle, slightly notched ; aperture short, 

 subovate, inner lip callous above ; columella 

 acute ; outer lip tumid within. 



G.)ULi>. ? MS. Brit. Mus. 



Hall. North America. 



Species 98. (Mus. Brit.) 



Rissoa (oina) villica. Eis. testd pyramidatd, acumi- 

 nata, albidd; anfradibus novetn, prope suturam 

 aiigulatis, eostis numerosis angulaiis longHudinali- 

 hus munitis ; ultimo infra medium spiraUter 

 eustaio, eostis longitudinalibus desinentibus ; aper- 

 turd parvd, subpyrifuniii ; columelld infra redd. 



The stewardess Rissoa. Shell pyramidal, acumi- 

 nated, whitish ; whorls nine, angular near the 

 suture, provided with numerous angular longi- 



Species 99. (JIus. Brit ) 

 Rissoa (oina) eulimoipes. h'is. /<■.</,? lirn-liiscnhi. 



all,d, politd, lateral iter arnn,/,!, acnuiinatd ; a„- 

 fradihns sriiis, Hllinin rnt,ni:i,: aperturd „l,Ji,p,; 

 produrld, I.,!,;., r.rterno inl'is i„rra.<.-.-a.lo ; Cnliu.idld 

 lata, rrassd, brevi. 



The eui.i.MA-SIIAI'ED Rissh.\. Slull r'ather short, white, 

 polished, laterally arched, acuminated; whorls 

 six, last rounded; apcrtiir'C obii(iuely produced, 

 outer lip thickened witliiii ; cdlumella broad, 

 thick, short. 



A. Adams. Proc. Zool. Soc. 1851, p. '279. 



Hab. Isl. Capul, Philippines. 



Species 100. (Mus. Brit.) 



Rissoa (oina) semiplicata. Bis. Irsfd pared, polild, 

 rede pyramidatd, teiini, seuiipelliicidd, leiiiiissime 

 lungitadiiialiter pUeafd ; aprrhird pa red, sidipt/ri- 

 J,.r,„i, lahio e.derno crasso, rulundo ; colunielld 

 pared, aciiiiiinatd. 



The half-plaited Rissoa. Shell small, polished, 

 smoothly pyramidal, thin, semipellucid, very 

 finely longitudinally plaited ; aperture small, 

 rather pyriform, outer lip thick, rounded ; 

 colnmella small, acuminated. 



Pease. Proc. Zool. Soc. 1802. 



Ilab. Pacific. 



Thinner, narrower, and more transparent than S. 



Iwvissima. 



Species inl. (Mus. Brit.) 

 Rissoa (oina) Bkowniana. Eis. testd pared, pyra 

 iiiidatd, acaminatd, falvd, licui; avfraditiiis sr,n': 

 alfiNsctdis, idtimo suhrotwmlo ; aperturd pyriform 

 lahio externa oblique produdo. 



