﻿CYEE>;A.— Plate XV. 



rioribus validis, continuis, versus marginem ven- 

 tralem evam'dis, postice ohsoleUs indutd ; latere 

 (Mitico breviuscwh, rotunda; latere postico fro- 

 djicio, late trurwato; -umbonihus oMusissimis, mar- 

 gine dorsali utrinque kevigato, margine ventral! 

 ceqnalifer convexo. 



The oval Cyeena. Shell ovate, tumid, covered with 

 a shining', blackish epidermis dying out towards 

 the ventral margin, posteriorly obsolete ; anterior 

 side rather short, rounded ; posterior side pro- 

 duced, broadly truncated ; nniboes very obtuse, 

 dorsal margin smooth on each side, ventral mar- 

 gin equally convex. 



])i:sHAYES. Proc. Zool. Soc. 1854, p. 343. 



II'il. Port Essington, Australia. 



Sijecics 78. (Mus. Brit.) 



Cykena maxima. Cyr. testa suhtrlgovii. itlli^simn, .luh. 

 roiiq>re,<isd, Icevi, rugis paucis, dislnnh'hu.^^ y.^s/Zft; 

 I'raiiidis irregulariter cincfd; ciinh'naidc jlarido- 

 suhaurantia indutd; latere aidico brevi, area 

 lumtlari convexd ; latere postico producto, infra 

 medium acuminatn, margine dorsali longe declivi, 

 convexo ; umbonibus elevatis ; margine ventraJi 

 jirominenter convexo. 



The vekt large Ctrena. Shell rather trigonal, very 

 high, rather compressed, smooth, irregularly 

 belted with few, distant wrinkles disappearing 

 posteriorly, covered with a yellowish-orano-e 

 epidermis ; anterior side short, lunular area 

 convex ; posterior side produced, acuminated 

 below the middle, dorsal margin with a long 

 slope, convex ; nmboes raised ; ventral margin 

 prominently convex. 



Ukshayes. Proc. Zool. Soc. 18G0, p, 321. 



H.,h. ? 



Species 79. (Mus. Brit.) 

 ( 'yrena Braziliana. Cyr. testa alia, tenuisslme liratd, 

 snhrotundd, intus alba; latere antico rotunda, 

 brevi; latere postico oblique producto, margine 

 dorsali longe- declivi; ejmlermide auranlio-sfra- 

 '■niined, castaneo angustti fasciatd, umbmibus ele- 

 vatis, versus laterem anticum dcclinatis. 



The Brazilian Cyeena. Shell high, very finely 

 grooved, rather rounded ; white within, anterior 

 side rounded, short ; posterior side obliquely 

 produced, dorsal margin with a long slope ; epi- 

 dermis orange-straw, with narrow bands of 

 chestnut; umboes raised, turned towards the 

 anterior side. 



Deshayes. Cat. Brit. Mus. 1854. 



Kab. Brazil. 



Species 80. (Mus. Brit.) 



Cyrena TENniSTRiATA. Cyr. testa subtrigond, altd, 

 pallide fidvd, fere Icevigatd, compressd, obscure 

 t"nuissime striata; latere antico brevi, usque ad 

 marginem ventralem declivi, margine ventrali rn- 

 tundo, producto, latere postico declivi, producto, 

 infra medium subacuminato, margine ventrali 

 sTirsiim aeclivi ; vmbonilvs elevatis. 



The FINK-STRIATED Cyrena. Shell subtrigonal, high, 

 pale fulvous, almost smooth, compressed, ob- 

 scurely, very finely striated ; anterior side short, 

 sloped down to the ventral margin ; ventral 

 margin round, produced, posterior side sloped 

 downwards, produced, slightly acuminated below 

 the middle, ventral margin sloped upwards; um- 

 boes elevated. 



Prime. Proc. Zool. Soc. 18G0, p. 323. 



Hub. ? 



Species 81. (Mus. Brit.) 



CvRENA Paracensis. Cyr. testa aUisslmd, augu.-^td, 

 liris irreguluribus post ice evanidis rugatd, obscure 

 ollvaced, int its purpurea ; latere antico brevissimo, 

 margine latcrali rectiiisculo ; latere postico, mar- 

 gine dorsali breviter declivi, margins laterali 

 oblique declivi; margine ventrali subconvexo. 



The Paraca Cyrena. Shell very elevated, naiTow, 

 wrinkled with irregular ridges, posteriorly fading, 

 obscurely olivaceous, purple within ; anterior 

 side very short, lateral margin rather straight ; 

 posterior side, dorsal margin shortly sloped, 

 lateral margin obliquely sloped ; ventral margin 

 rather convex. 



D'Orbigny ? MS. Brit. Mns. 



Eal. Paraca. 



