GENERA OF SHELLS. 83 



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

 nosa, bufonia, granulata, granifera, semigranosa, bitubercu- 

 laris, ranina, anceps, pygmrea, lasvigata, 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 struthiolaria 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 icith slender, abrupt tails, always longer than the 

 aperture. 



M. cornutus, brandaris, crassispina, tenuispina, rarispiria, 

 ternispina, brevispina, haustellum, tenuirostrum ; motacilla. 

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

 varices. 



M. inflatus, elongatus, palmarosee, brevifrons, calcitrapa, 

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

 lus, capucinus, asperrimus, phyllopterus, acanthopterus, 

 tripterus, trigonularis, uncinarius, hemitripterus, gibbosus, 

 triqueter, trigonulus. 



(b.) More than three varices. 



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

 gonus, scorpio, secundus, quadrifrons, turbinatus, trunculus, 

 anguliferus, melonulus, 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. 



