480 Zoological Society. 



meant to be represented in fig. 69 of the ' Conchological Illustrations,' 

 which is mentioned as a variety of M. Motacilla, though there are 

 still some little points of difference. A line specimen often permits 

 a conchologist to clear up his doubts as to specific importance, and 

 I have had the assistance of such in drawing up the above descrip- 

 tion. Indifferent specimens are not uncommon, and Mr. Sowerby, 

 jun. had most probably only such, and was compelled to leave it as 

 a variety of M. Motacilla. 



MuREX CENTRiFUGA. Muv. tcstd gracilUme fiisiformi, pallide cor- 

 ned, passim creberrime striatd ; varicibus tribus, subalatis, in spi- 

 nis compressis laciniatis ; spind ad unguium anfraciuum elongatd, 

 subrectd ; interstitiis nodo unico ; aperturd elongatd, ovali ; labro 

 intiks Icevi ; canali mediocri, rectiusculo, clauso, ad basin subre- 

 curvo. Axis 16 lin. 

 Hab. West coast of Veragua ; on a sandy floor in fifty-two fathoms. 

 This species has the general character of M. pinniger and M. ca- 

 pensis, and is very closely allied to the latter. 



MuREX FESTivus. Mur.testdfusiformi, crassd, fulvd, trivaricosd ; 

 varicibus simplicibus, recurvis, superne cristatis, subtilissime cre- 

 niferis ; interstitiis nodulosis, lineis subgeminis transversis fuscis 

 eleganter ornatis ; aperturd ovali ; labro intils sparsim denticulato ; 

 canali valde clauso, ad basin subrecurvo. Axis 13 lin. 

 Hab. Bay of Madalena, California ; dredged from seven fathoms, 

 on a sandy floor. 



MuREX FovEOLATUS. MuT. tcstd fusiformi, crassd, multivaricosd, 

 transversim creberrime sulcatd, laminis minimis longitudinalibus 

 foveolatd atro-purpureo pallide bifasciatd ; varicibus septenis sim- 

 plicibus, postice rotundatis, antice 7nargine acutd ; aperturd ovali, 

 coarctatd ; labro intils obtuse denticulato ; labio interno producto ; 

 canali aperto, subrecurvo. Axis 12^ lin. 

 Hab. Bay of Madalena, California ; with the preceding. 

 MuREx ANANAS. Mur. tcstd fusiformi, ventricosd, crassd, multi- 

 varicosd ; anfractibus septenis superne subplanulatis, transversim 

 costatis, costis alternate minoribus ; varicibus senis rotundatis 

 spiniferis, spird supremd prcecipue maximd, brevi, rectd, solidd, 

 biplicatd, transversim compressd, ceteris brevissimis subcequali- 

 bus; aperturd rosed, rotundatd, sen paulisper elongate ovali, postice 

 canaliculatd ; canali mediocri, subobliquo, aperto, margine columel- 

 lari rugulosd, dorso bifariam spinoso, serie supremd superante. 

 Hab. West coast of Africa. Mus. Cuming. 



A shell closely resembling M. 7'osarium in its size and proportions, 

 but finds its specific distinction in its greater massiveness, the superior 

 size of its upper series of spines, and the absence of nodules on the 

 interstitial ribs. Both shells have a distinct fasciation of three dark 

 bands, but our species is entirely wanting in that beautiful and ele- 

 gant covering of stri?e which is so conspicuous in the fine specimen 

 of M. rosarium in Mr. Cuming's collection. 



MuREx Belcheri. Mur. testd magnd, fusiformi, crassd, ponder osd, 

 pallide fused, multivaricosd ; anfractibus quadratis, albo fascia- 



