GENERA OF SHELLS. 83 



R. gigantea, leucostoma, candisata, argus, crumena, spi- 

 nosa, bufonia, granulala, granifera, semigranosa, bitubercu- 

 îaris, ranina, anceps, pygmaea, laevigata, — caudata. 



MuREX. Shell ovate or oblong, channelled 

 at base, with rough tubercular or spiny varices 

 without. Aperture rounded ; varices three or 

 more on each whorl, the inferior obliquely 

 joined to the others by a longitudinal series. 

 Operculum horny. 



The striithiolaria has only one varix, which is on 

 the right lip : the ranella two, at opposite sides of the 

 shell, and the murex three or more on each whorl, 

 forming longitudinal rows on the shell, inclining to- 

 wards one side near the summit of the spire. 

 (I.) Shells zcitk slender, abrupt tails, always longer than the 

 aperture. 



M. cornutus, brandaris, crassispina, tenuispina, ranspina, 

 ternispina, brevispina, haustelluni, tenuirostrum, niotacilla. 

 (2.) Tails tJiick, not abrupt, more or less long. — (a.) Three 

 varices, 



M. inflatus, eloiigatus, palmarosae, brevifrons, calcitrapa, 

 adustus, rufus, axicornis, cervicornis, aculeatus, microphyl- 

 lus, capucinus, asperrimus, pbyllopterns, acanthopterus, 

 tripterus, trigonularis, uncinarius, hemitripterus, gibbosus. 

 triqueter, trigonulus. 



(b.) More than three varices. 



M. brassica, saxatilis, endivia, radix, niolanomathos, hexa- 

 gonus, Scorpio, secundus, quadrifrons, turbinatus, trunculus, 

 anguliferus, nielonulus, Magellanicus, lamellosus, erinaceus, 

 Tarentinus, scaber, costularis, polygonulus, vitulinus, an- 

 gularis,crispatus,fenestratus, cingulatus, cinguliferus, subca- 

 rinatus, torosus, lyratus, concatenatus, granarius, fimbriatus, 

 pulchellus, aciculatus, tripteroides, tricarinatus. 



