SPONDYLUS. 



Genus SPONDYLUS. Lnni^tus. 

 Tcsin affixa, i>i,pi/>iiriilrix, ir mi id, iris, plus minus aiiricti- 

 lata, rniVuitiiii xtriatu et tirnlii, runt costata, varie nm- 

 ricata el spiiiom ; uhiboiiibiis icqitaUbus, area cardinali 

 permtiplfi, plmin, eetate productiore, pecuUariter sepa- 

 ratis. Cardo dentihus duohm solidis, re/lexis in ntrn- 

 qm valvfl, valide intersertis, ligamenUmi in cavHalem 

 inter se recipleiitibns. Impressio muscularis mbla- 

 teralis. 

 Shell attached, inequivalve, irregular, more or less auricu- 

 lated, radiately striated and ridged, rarely ribbed, va- 

 riously prickled and spined ; umboes equal, peculiarly 

 separated by a very large flat hinge area, more and 

 more produced with age. Hinge with two solid re- 

 flected teeth in each valve, strongly interlocking, and 

 receiving the ligament between them. Muscular im- 

 pression sublatcral. 

 The Spondylus, or Thorny Oyster, is one of the earliest 

 known shells. When Aristotle occupied himself with phi- 

 losophic interest in describing the animals of the Mediter- 

 ranean, the -S". (jftdaropus lived, as now, in all its royal 

 panoply of purple and white, and the name adopted by 

 Linnaeus when engaged upon the grand formula of nomen- 

 clature which has become the law of naturalists, was that 

 of the old philosopher of Greece, namely, SiroVSuXos. The 

 species added to this genus in modern times are compa- 

 ratively few ; Lamarck numbered twenty-one ; Sovverby, in 

 liis recent monograph in ' Thesaurus Conchyliorum,' only 

 thirty-four, and I have but two or three to add. The species 

 are mostly well known to collectors, all having an attrac- 

 tive interest from their singularity of form and beauty of 

 colouring. Their grow'th is peculiar and extremely irre- 

 gular, varying according to the circumstances of their place 

 of attachment ; it may be remarked, however, that it is on 

 the upper valve that the shell developes its truest specific 

 cliaracter. 



The Sporiihjll are confined to no particular locality. 

 Limited as they are in species, they are distributed very 

 generally over the globe south of the latitude of the Medi- 

 terranean. There are no sjiecies on the coast of Britain. 



Species 1. (Mus. Cuming.) 

 Spondylus Pacificus. Spond. testa, oblique late trigonii, 

 compressd, radiatim tenue imhricato-striatd et liratn, 



Januar 



liris subcoiitorli''Jte.rHOsis, tenuissime sqnamatis, squumis 

 interdumfere obsoletis ; rtibidd vel rosed, interdmii al- 

 lidd, minio radiatd. 

 The Pacific Spondylus. Shell obliquely broadly tri- 

 angularly compressed, radiately finely imbricately stri- 

 ated and ridged, ridges somewhat twistedly flexuous. 

 very finely scaled, scales sometimes almost obsolete; 

 ruddy or rose-coloured, sometimes whitish, rayed with 

 vermilion. 

 Ilab. Lord Hood's Island, Pacific Ocean ; Cuming. 



This species has been sometimes regarded as a variety 

 of S. ««(/h.s which follows, but it is uniformly distinguished 

 by a characteristic obliquely triangular compressed growth, 

 rayed with exceedingly fine squamate ridges and striae. 

 Mr. Cuming possesses it in several varieties. 



Species 3. (Mus. Cuming.) 

 Si'ONDYLUs NUDUS. Spoiid.. testd snbelongato-lriijoiiii, (jib- 

 Losii, nmbones versus rotundato-tumidd, radiatim, deiisi- 

 slrialn et interdum. liratd, siriis vix imbricatis, sublo'- 

 ribiis, liris posticis versus marginal interdum squama- 

 tis, auriculis Icevibus ; vivide minid, lineis albis remotis 

 plerumqne radiatis. 

 The denuded Spondylus. Shell somewhat elongately 

 triangular, gibbous, rotundately swollen towards the 

 umboes, radiately densely striated and sometimes 

 ridged, strife scarcely imbricated, nearly smooth, pos- 

 terior ridges sometimes scaled towards the margin, 

 auricles smooth ; bright scariet, generally rayed with 

 distant white lines. 

 Chemnitz, Conch. Cab. vol. xi. p. 233. pi. 203. f. lOS'J, 



1990. 

 Hab. Mauritius and Philippine Islands ; Cuming. 



A richly painted vermilion shell, mostly rayed at rather 

 distant intervals with white lines. It is at once distin- 

 guished from the preceding species by its elevated regular 

 gibbous growth, and ab.sence of scales, except in advanced 

 specimens at the ends of the posterior ridges. 



Species 3. (Mus. Cuming.) 

 Spondylus varians. Spond. testa oblongo-orbicidari, 

 convexo-depressn, suUrregulari, spinis brevibtis sqiiu- 

 ?iiatis copiosP radiata, spinis valde irregularibws, valvd 



1856. 



