PECTUNCULUS. 



Plate V. 



Species 20. (Mus. Cuming.) 



Pectunculus bicolor. Pect. testd suborbiculari, mn- 

 bones versus attenuate!, longitudinaliter sulcatd, sulcis 

 numerosis, angustis; alb'uhi, violaceo nebulosd, macu- 

 lis trigonis ferrugineo-rubidis irregulariter pictd. 

 The two-coloured Pectunculus. Shell somewhat 

 orbicular, attenuated towards the umbones, longi- 

 tudinally grooved, grooves numerous and very nar- 

 row ; whitish, clouded with violet, and irregularly 

 painted with triangular rusty reddish spots. 

 Reeve, Pro. Zool. Soc, 1843. 

 Huh. Gulf of California. 



Mr. Gray appears to have mistaken this shell(Zoology 

 of Beechey's Voyage in the Blossom) for the Pectuncu- 

 lus inaqualis. 



Species 21. (Mus. Cuming.) 



Pectunculus pallium. Pect. testd oblique ovatd, sub- 

 quadratd, radiatim costatd, costis lecvibus, prope mar- 

 ginem subobsoletis ; luteold, maculis rubidis, quadratis, 

 spar sis, vivide, pictd. 



The mantle Pectunculus. Shell obliquely ovate, 

 squarish ; radiately ribbed, ribs nearly obsolete to- 

 wards the margin ; yellowish, vividly painted with 

 scattered square reddish spots. 



Reeve, Pro. Zool. Soc, 1843. 



Hah. Zanzibar. 

 This shell maybe easily recognised by the dark ruddy 



spots which are sparingly scattered here and there upon 



the warm uniform ground which covers the surface. The 



cardinal portion of the shell is rather solid. 



Species 22. (Mus. Cuming.) 

 Pectunculus nodosus. Pect. testd suborbiculari, fuiro, 

 furvo castaneove variegatd ; radiatim costatd, costis 

 nodosis ; intus albidd, ant ice fuscescente. 

 The knobbed Pectunculus. Shell somewhat orbi- 

 cular, yellow, variegated with dusky brown or 

 chestnut ; radiately ribbed, ribs knobbed ; interior 

 whitish, brown anteriorly. 

 Reeve, Pro. Zool. Soc, 1843. 

 Hab. Ceylon. 

 The knobs on the ribs, by which this species is chiefly 



characterized, are much more strongly developed on the 

 posterior side of the shell ; on the anterior side they are 

 almost obsolete. 



Species 23. (Mus. Cuming.) 



Pectunculus eubens. Pect. testd orbiculari, valde 

 convexd, striis tenuissimis decussatd ; pallide rubente, 

 7naculis lineisque rubris numerosis vivide pictd ; urn- 

 bonibus subobliquis ; intus fuscescente. 

 The red Pectunculus. Shell orbicular, very convex, 

 decussated with very fine striae ; pale red, vividly 

 painted with numerous blotches and longitudinal 

 lines of dark red ; umbones rather oblique ; interior 

 brownish. 

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

 p. 490. 



Hab. ? 



This shell, which I believe to be the' Pectunculus rubens 

 of Lamarck, differs materially from the Pectunculus 

 ylycimeris. It is rounder, considerably more ventricose, 

 and profusely splashed with a much deeper red. 



Species 24. (Mus. Cuming.) 



Pectunculus pennaceus. Pect. testd orbiculari, tumi- 

 dd, decussatim striatd, striis longitudinalibus fortio- 

 ribus; albidd, maculis fuscis grandibus et parvis irre- 

 gulariter pictd ; umbonibus ligamenti extremitate un- 

 tied inflexis. 



The feathered Pectunculus. Shell orbicular, swollen, 

 decussately striated, longitudinal striae the stronger; 

 whitish, irregularly painted with large and small 

 dark brown spots ; umbones bent inwards to the 

 anterior end of the ligament. 



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

 p. 490. 



Hab. Island of St. Thomas, &c, West Indies. 



The umbones of this shell meet in a remarkable manner 



quite at one extremity of the ligament. It often attains 



a larger size than that of the specimen here figured. 



Species 25. (Mus. Cuming.) 



Pectunculus lineatus. Pect. testa orbiculari, convexd, 

 subauriculatd ; decussatim striata, striis longitudina- 



April 1843. 



