PURPURA. 



Plate IX. 



Species 39. (Mus. Cuming.) 



Purpura thiarella. Pitrp. testa ovata, subincrasmtd, 

 spird breviuscidd, angulato-acuminatd, anfractibits 

 tranwersim subtiliter Uratis, longltudinaliter subpli- 

 catis, mipeme concavo-angtdatis, ad angulnm tubercu- 

 lato-coronatis ; cinereo-grked, columelld albidd, aper- 

 t lira fame liitescente. 



The little crown Purpura. Shell ovate, somewhat 

 thickened, spire rather short, angularly acuminated, 

 whorls transversely ridged, longitudinally subplicated, 

 concavely angulated round the upper part, tuber- 

 cularly coronated at the angle ; ashy gi-ey, columella 

 whitish, interior of the aperture yellowish. 



Lamarck, Anim. sans vert. (Deshayes' edit.), vol. x. p. 83. 



Hab. Island of Vanikoro ; Quoy. 

 Approaching very closely to the P. imperialis, but 



constantly distinguishable by its more solid gTowth and 



stouter and ruder form. 



Species 40. (Mus. Cumiug.) 



Purpura cataracta. Purp. testd oblongo-ovatd, Bucci- 

 niformi, scabrd, transversim siibobsolete sulcatd, striis 

 longitudinaUbus oldiqtie decnssantibus ; columelld plano- 

 dspressd, aperturd inflatd ; griseo-albicante, strigis ni- 

 gricantibus, irregulariter tmdulatit, lougitadinatiter 

 pictd, columelld et apertures fauce purpm-eo-fiiscis. 

 The cataract Purpura. Shell oblong-ovate, Buccinum- 

 shaped, rough, transversely obsoletely grooved, with 

 longitudinal strise crossing obliquely ; columella flatly 

 depressed, apertm-e inflated; gi-eyish-white, painted 

 longitudinally with irregidarly undulating black 

 streaks, columeDa and interior of the aperture pm-ple- 

 brown. 



Buccinum cataracta, Chemnitz, Conch. Cab. vol. x. 

 p. 188. pi. 152. f. 1-155. 



Hah. ? 



No author appears to have yet succeeded in identifying 

 the mysterious Buccinum cataracta of Chemnitz ; it is easy 

 to frame a description refemng to it, as did Lamarck, or 

 to criticise the illustrations of others, as M. Deshayes has 

 very properly done, but the test of an author's researches 

 is to produce the shell. M. Kiener in attempting this, 

 has unfortunately added to the confusion ; in his mono- 

 graph of Purpura, he has figured at least two, if not tb-ee, 



species for P. cataracta and varieties, not one of which 

 exhibits the slightest approach to Chemnitz's figure, and 

 all presenting the ordinary character of a gi-ooved aperture, 

 the absence of which in the Buccinum cataracta is one of 

 its distinguishing features. Again, on referring to M. 

 Kiener's monograph of Buccinum, it will be found that he 

 has figured another totally dift'erent shell under the name 

 of B. Belalandi, referring, for the sake of illustration, to 

 Chemnitz's figure of B. cataracta. If M. Kiener regarded 

 that shell as the species now under investigation, why 

 not have adopted Chemnitz's name, instead of compli- 

 menting M. Delalande in opposition to the ordinary rules 

 of nomenclature ? we are all liable to error, and to avoid 

 it is impossible, but the necessity for such a reiteration 

 of critical correction as the labours of this author invoke, 

 becomes irksome. 



The specimen here described and figured for the P. 

 cataracta does not accord so intimately with Chemnitz's 

 figiu-e as coidd be wished, but I believe it to be the shell 

 intended, and leave others to form theii' own opinion of the 

 accuracy of my views. It is a rough shell, obscurely 

 grooved and striated, conspicuously and most u'regularly 

 undulated with black upon a white gi-ound, the columella 

 and interior of the aperture being perfectly smooth, and 

 of a chocolate or purple-brown colour. 



Species 41. (Mus. Cuming.) 



Purpura Blainvillii. Purp. tedd ovatd, spird subacu- 

 minatd, anfractibus tranwersim nodoso-costatis, inter- 

 stitiis subtiliter Uratis; columelld subangustd, labro 

 inttcs sulcata, margine denticulato ; aperturd subiu- 

 fafd; fused, columelld albd,ferrugineo-rufo marginatd. 



De Blainville's Purpura. Shell ovate, spire a little 

 acuminated, whorls transversely nodosely ribbed, in- 

 terstices finely ridged ; columella rather narrow, lip 

 gi-ooved within, denticulated at the margin ; aperture 

 a little inflated ; brown, columella white, edged with 

 feiTuginous red. 



Deshayes, Anim. sans vert. vol. x. p. 93. 



Purpura Callaoensis, De Blainville, Kiener, (not of 

 Gray). 



Sai. Bay of Callao, Peni. 



A light, rather delicately formed shell, in which the 

 columella is edged with dark red. 



September, 1846. 



