FISSURELLA. 



Plate XIl. 



Species 79. (ilus. Cuming.) 



FissURELLA ROTA. Fiss. testd ovaid, dvpressiusculd, ra- 

 diatim obscure obtuse liratd, liris sulcis concent ricU 

 decussatis, oi-ificio elongato-obloiigo, lateribtis subcon- 

 tmcto ; olivaceo-fuscd, conspicue albiradiatd, radiis 

 prope manjbiem fusco-punctatls, circa ori/icium rosaced. 



The wheel Fissurella. Shell ovate, rather depressed, 

 radiately obscurely obtusely ridged, ridges decussated 

 with coucentric grooves, orifice elongately obloug, a 

 little contracted at the sides ; olive-brown, conspicu- 

 ously white-rayed, rays blotched near the margin 

 with brown, pink round the orifice. 



Hub. Ca])e of Good Hope. 



The wliite rays have a raised appearance in this species 



and are very characteristic. 



Species 80. (Mus. Cuming.) 



PissUBELLA STELLATA. Fiss. tesld ovaid, depressd, medio 

 elevaliusculd, obscure Uriradiald, liris obsolete nodulosis, 

 orificio obloiiffo, subangusto, laleribus medio excavalis ; 

 albidd, rufescente radiatd, radiis nigricante-purpureo 

 maculatis, margiue iuterno late tessellato. 



The STARRED Fissurella. Shell ovate, depressed, 

 rather elevated in the middle, obscm'ely rayed with 

 ridges, which are obsoletely nodidous, orifice obloug, 

 rather narrow, sides excavated in the middle ; whitish, 

 rayed with light red, the rays being blotched with 

 blackish pm-ple, internal margin broadly tessellated. 



Uab. Valparaiso (attached to dead shells at a depth of 

 from six to twelve fathoms) ; Cuming. 



A very prettOy rayed species, distinguished internally 

 by the broad tessellated painting of the margin. 



Fig. SI. (Mus. Cuming.) 

 The shell here represented proves to be a smooth variety 

 3f F. rota described above, and is from the same localitv. 

 ForSp. 81 seePl.XV. 



Species 83. (Mus. Cuming.) 

 is.suiiELLA Cayennensis. Fiss. testa ovaid, convexo- 

 conicd, lateribus subeompressd, radiatim multiliratd, 



tins tenuibiis, slriis coiiceutrici.s uuinerosis decussalis. 

 margiue subfiliter crenulato, orificio oblotigo, lateribus 

 medio excavati.s, antice inclinato ; albidd, fusco varie- 

 gaid, circa orijicium carulescente. 

 The Cayenne Fissurella. Shell ovate, convexly co- 

 nical, rather compressed at the sides, radiately many- 

 ridged, ridges fine, decussated with numerous cou- 

 centric striae, finely crenulated at the margin, orifice 

 oblong, sides excavated in the middle, inclined an- 

 teriorly; whitish, variegated with brown, blinsli 

 around the orifice. 

 LAJtARCK, Anim. sans vert. (Deshayes'edit.) vol.vii. p..5ii-t. 

 Hob. Cayenne, Guiana. 



The close-set radiating ridges, which form at their ex- 

 tremity the finely crenulated margin, are about eijilitv m 

 number. 



Species S3. (^lus. Cuming.) 



Fissurella crexifera. Fiss. testd ublongo-omtd, de- 

 pressd, radiatim costafd et striatd, eostk mnrimto- 

 nodosis, striis coneentricis obsolete squamato-decussatis, 

 margiue vLv crenulato, orificio elongato-oUongo, lateribus 

 medio excavatis ; albo et fusco-rufo late radiatd. 



The crenulated Fissurella. Shell oblong-ovate, de- 

 pressed, radiately ribbed and striated, ribs muricately 

 nodose, obsoletely scpiamately decussated with con- 

 centric stri;e, margin scarcely crenulated, orifice elon- 

 gately oblong, sides excavated in the middle : broadly 

 rayed with white and brown-red. 



SowERBY, Pro. Zool. Soe. 1834, p. 128. 



Uab. lical Lltjjo, Central America. 



This species is not sufficiently crenulated to be entitled 



to the specific name which has been applied to it. 



Species S-i. (Mus. Cuming.) 

 Fissurella alternata. Fiss. testd oblmgo-ovatd, ■■ml,- 

 qiiadratd, elevatd, lateribus subeompressd, radiatim. cos- 

 lata, costis angusti.i, liris iribus parvitisculis in inter- 

 stitiis, lamiuis numerosisjimbriatis coneentricis midiqiie 

 sqiiamuto-decussald, orijicio subqiiadrato-oblottgo, aiitice 

 iiirtinato, laleribus medio excavatis ; albidd, cintm- 

 oUmceo pallidi macidatd et radiatd, ante orijiriui/i 

 ccerulescente. 



