P ECTUNCULUS. 



Plate IX. 



Species 9. (Second notice.) 

 Variety /3. (Fig. 9 b, Mus. Cuming.) 

 Pectunculus violascens. Testa purpureo-violacea, ci. 

 nereo zonata, maculis albidis numerosis undulatis 

 prope umbones aspersa ; st?-iis longitudinalibus sim- 

 plicissimis, striis numerosis, subtilissime pertusis, de- 

 cussatis. 

 Shell purple-violet, zoned with dark ash-colour, and 

 sprinkled near the umhones with numerous waved 

 specks of white; longitudinal strias very simple, 

 crossed transversely with numerous finely pricked 

 stria?. 



Pectunculus zonalis ? Lamarck. 

 Hab. Mediterranean. 



There appears to he little doubt but that Lamarck's 

 Pectunculus zonalis is nothing more than a variety of 

 the Pectunculus violascens, somewhat approaching to that 

 here represented. 



The figure given of this species at Plate II. is so in- 

 differently executed, that I embrace the opportunity of 

 illustrating it with a more striking example. 



Species 49. (Mus. Cuming.) 



Pectunculus sekicatus. Pect. testd orbiculari.pectini- 

 formi, depressiusculd, albidd, rosaceo-fusco sparsim 

 tinctd et maculatd, epidermide sericea crassd indutd ; 

 radiatim sulcatd, sulcis subdistantibus ; intus albd. 



The silk-clad Pectunculus. Shell orbicular, some- 

 what pecten-shaped, rather depressed, whitish, 

 stained and spotted with light pinkish brown, co- 

 vered with a thick silken epidermis ; radiately 

 grooved, grooves rather distant ; interior white. 



Reeve, Pro. Zool. Soc, 1S43. 



Hab. Island of Tortola, West Indies. 



This exceedingly delicate shell is remarkable for its 

 glossy silken epidermis ; the hinge-shelf in the interior 

 of each valve is nearly as broad and solid as that of the 

 Pectunculus strigilatus, and the teeth are as closely set ; 

 the shell altogether exhibits many characters in common 

 with that species, but no indication of the peculiar man- 

 ner in which it is attenuated towards the umbones. 



This is the only specimen 1 have seen at present. 



Species 50. (Fig. a, Mus. Cuming; Fig. 6, Mus. Brit. | 

 Pectunculus radians. Pect. testd suborbiculari, in- 

 cequilaterali, subdepressd ; fulvd , rubido- autviolaceu- 

 fusco lateraliler zonatim tinctd, epidermide pilosd 

 prope marginem indutd ; radiatim costatd, costis ti - 

 nuibus, interdum subobsoletis, longitudinaliter striatis, 

 crcberrimis ; intus albidd, prope marginem vividi 

 purpureo-violacea . 

 The radiating Pectunculus. Shell orbicularly ovate, 

 inequilateral, somewhat depressed; yellowish brown, 

 stained at the side in a more or less zoned manner 

 with reddish or violet-brown, covered near the 

 margin with a hairy epidermis; radiately ribbed, 

 ribs thin, sometimes rather obsolete, longitudinally 

 striated, very close- set ; interior white, deep pur- 

 ple-violet near the margin. 

 Lamarck, Anim. sans vert. (Deshayes' edit.), vol. vi. 



p. 495. 

 Hab. Port Philip, Port Lincoln, South Australia. 



Having lately received specimens of this very pretty 

 shell from the locality above-mentioned, I have much 

 pleasure in being enabled to illustrate an unfigured 

 species of Lamarck, which I had almost despaired of 

 identifying. 



Species 51. (Mus. Burt.) 



Pectunculus lividus. Pect. testd orbicular!, tumidd, 

 inmquilaterali, antice angulatd; longitudinaliter ra- 

 diatd, radiis latis, elevatiusculis, subtilissime striatis, 

 rubido-fuscis, marginem versus livido-ca-siis. epider- 

 mide pilosd plus rninusve indutis ; radii* anticis cre- 

 berrimis ; umbonibus recti incurvis, maculis a 

 perpaucis circumsparsis ; intus albd, medio purpureo- 

 nigricante tinctd et maculatd. 

 The livid Pectunculus. Shell orbicular, swollen, in- 

 equilateral, angulated on the anterior side ; longi- 

 tudinally rayed, rays broad, rather elevated, very 

 finely striated, reddish brown, livid- blue towards 

 the margin, more or less covered with a soft fa lirj 

 epidermis ; anterior rays very closely set ; umbones 

 straightly incurved, a very few white specks scat- 

 tered around ; interior white, middle very deeply 

 stained and spotted with purple-black. 

 Reeve, Pro. Zool. Soc, 1843. 

 Hab. Red Sea. 



December 1843. 



