PECTUNCULUS. 



Plate VI. 



Species 27. (Mus. Cuming.) 



Pectunculus striatularis. Pect. testa depresso-cor- 

 datd; albido-mfescente, striis lineisque rufis longi- 

 tudinalibus, numerosissimis, ornatd; umbonibus sub- 

 obliquis. 



The finely-striated Pectunculus. Shell depressly 

 heart-shaped ; ruddy white, ornamented with a 

 number of longitudinal red lines and striae; urn- 

 bones rather oblique, tipped with white. 



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

 p. 493. 



Hab. Swan River. 



In light varieties of this species the red longitudinal 

 lines are much more vividly painted than in the specimen 

 here represented, particularly towards the umbones. 



Species 28. (Mus. Cuming.) 



Pectunculus pectinatus. Pect. testd lenticulari, de- 

 presso-convexd, longitudinaliter costatd, costis crebris, 

 transverse striatis ; albidd, maculis caruleo-fuscis 

 paucis, subquadratis, et lineis varii' pictd. 



The pectinated Pectunculus. Shell lenticular, de- 

 pressly convex, longitudinally ribbed, ribs nume- 

 rous, transversely striated ; whitish, variously paint- 

 ed with lines and a few squarish blue-brown 

 blotches. 



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

 p. 494. 



Area Pectunculus, minor, Chemnitz, Conch., vol. vii. 

 pi. 58. f. 570, 571. 



Hab. Island of La Plata (found in coral sand at the 

 depth of seventeen fathoms) ; Cuming. 



The ribs in this shell are obliquely crossed here and 

 there with fine lines in the same manner as those of the 

 P. Pectiniformis ; the dark blotching is somewhat irre- 

 gular, and always thicker towards the umbones. 



Species 29. (Mus. Cuming.) 



Pectunculus tessellatus. Pect. testd orbiculari, um- 

 bones versus triangulariter attenuatd,subglobosd,albd, 

 purpureo-laccd tessellatd ct variegatd ; longitudina- 

 liter costatd, costis rotundatis, subdistantibus. 



The tessellated Pectunculus. Shell orbicular, tri- 

 angularly attenuated towards the umbones, rather 



globose, white, tessellated and variegated with 



purple lake ; longitudinally ribbed, ribs rounded 



and rather distant. 

 Sowerbt, Pro. Zool. Soc, 1832. 

 Hab. Monte Christi and Xipixapi, West Columbia (found 



in sandy mud at the depth often fathoms) ; Cuming. 



A solid and globose shell, very neatly tessellated with 

 rich purple lake spots. 



Species 30. (Mus. Cuming.) 

 Pectunculus angulatus. Pect. testa depresso-cordatd, 

 an t ice angulatd, longitudinaliter sulcato-lineatd el 

 striata ; castaneo-fuscd, alba plus miniisve nebulosd, 

 ared ligamenti breviusculd. 

 The angulated Pectunculus. Shell depressly cordate, 

 anteriorly angulated, longitudinally deeply lined 

 and striated ; dark chestnut-brown, more or less 

 splashed with white ; area of the ligament rather 

 short. 

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

 p. 491. 



Area subangulata, Chemnitz, Conch., vol. vii. pi. 57. 

 f. 567. 

 Hab. Catbalonga, Island of Samar, Philippines (found 

 in coarse sand at the depth of eight fathoms) ; Cu- 

 ming. 

 The specimen here figured exhibits no white, excepting 

 at the tips of the umbones ; but I have seen specimens 

 with the angulated portion of the shell almost entirely 

 white, and it is a very pure white. The longitudinally- 

 grooved lines of a light fulvous colour are very finely 

 wrought upon the dark chestnut ground of the shell. 



Species 31. (Mus. Cuming.) 

 Pectunculus strigilatus. Peel, testa suborbiculari, 

 umbones versus triangulariter attemtatd, ventricosd; 

 albidd, roseo tinctd, et rubiginoso striatd et variegatd ; 

 longitudinaliter costatd, costis rotundatis, subdistan- 

 tibus, intcrstitiis larvibus. 

 The comb-like Pectunculus. Shell nearly orbicular, 

 triangularly attenuated towards the umbones, ven- 

 tricosc ; whitish, stained with rose, striated and 

 variegated with rust colour ; longitudinally ribbed, 

 ribs rounded, rather distant, interstices smooth. 

 Sowerby, Pro. Zool. Soc, 1832. 



April 1843. 



