PLEUROTOMA.— Plate VI. 



vividly painted with a single brown spot ; whorls 

 tuberculated in the middle, the tubercles in some 

 specimens flowing down in the form of ribs ; aper- 

 ture short, lip expanded, deeply sinuated ; canal 

 short, recurved. 



Sowerby, Pro. Zool. Soc, 1833, p. 134. 



Reeve, Couch. Syst., vol. ii. pi. 233. f. 9. 



Hab. West Columbia and Central America. (Found in 

 sandy mud in from eight to sixteen fathoms.) 



This beautiful shell, which has been collected both by 

 Mr. Cuming and Capt. Belcher, may probably be merely a 

 white variety of the PI. gibbosa, Kiener, Murex gibbosus, 

 Chemnitz (see the preceding Plate, fig. 30.). I must 

 say, however, that I find no intermediate variation be- 

 tween the ashy dulness of the PL gibbosa and the ivory 

 brightness of the PI. unimaculata. 



Species 43. (Mus. Cuming.) 



Pleurotoma rosea. Pleur. testd turritd, acuminata, 

 albidd, antice roseo-tinctd ; anfractibus valde tuber- 

 culatis, tuberculis ovatis, antice in costellas conftuen- 

 tibus ; labro expanso, profundi sinuato; canali brevi, 

 recurvo. 

 Tue rose-tinted Pleurotoma. Shell turrited, acumi- 

 nated, white, rose-tinted anteriorly ; whorls strongly 

 tuberculated, tubercles ovate, flowing anteriorly 

 into ribs, as visible on the last whorl ; lip expanded, 

 deeply sinuated ; canal short, recurved. 

 Sowerby (not of Quoy), Pro. Zool. Soc, 1833, p. 134. 

 Reeve, Conch. Syst., vol. ii. pi. 133. f. 3. 

 Hab. Salango and Monte Christi, Central America 

 (found in sandy mud at a depth of twelve to six- 

 teen fathoms) ; Cuming. 

 The penultimate tubercle of this shell becomes en- 

 larged into a kind of hump like the spot which charac- 

 terizes the preceding species, and as there are many spe- 

 cies which exhibit this peculiarity of increase just prior 

 to their reaching maturity, I should suppose it to depend 

 upon some peculiar economy in the animal inhabitant. 



Species 44. (Mus. Stainforth.) 



Pleurotoma spirata. Pleur. testa subobeso-conicd, 

 acute turritd, laviusculd, cinered, fusco leviter nebu- 

 losd ; anfractibus planis, superne angulatis, parte 

 superior! in aream planum spiraliter ascendente ; labro 

 acuto, sinu subcentrali ; canali longiusculo. 



The spiral Pleurotoma. Shell rather stoutly conical, 

 sharply turrited, rather smooth, ash colour, slightly 



clouded with brown ; whorls flat, angulated round 

 the upper part, which ascends spirally with a flat 

 area ; lip sharp, sinus near the centre ; canal rather 

 long. 



Lamarck, Anim. sans vert., vol.vii. p. 93 ; Enc. Meth., 

 pi. 440. f. 5. a and b. 



Hab. ? 



Lamarck refers this shell to the Murex Perron of 

 Chemnitz, under the impression that the transverse 

 ridges represented in that figure (Conch. Cab. vol. x. 

 pi. 164. f. 1573.) were worn off in his specimen of PI. 

 spirata. I have, however, a shell before me of very dif- 

 ferent character (Pleurotoma Perronii, nobis), answering 

 exactly to the figure in question. 



Species 45. (Mus. Stainforth.) 



Pleurotoma maculosa. Pleur. testd oblongo-fusiformi, 

 turritd, carulescente, fusco-maculosd ; anfractibus 

 lavigatis, medio tuberculiferis, tuberculis uniseriali- 

 bus ; aperlurd oblongd ; sinu lato ; canali brevi. 



The spotted Pleurotoma. Shell oblong, fusiform, 

 turrited, bluish, spotted with brown ; whorls smooth, 

 tuberculated in the middle, tubercles in one regular 

 series ; aperture oblong, sinus broad ; canal short. 



Sowerby, Pro. Zool. Soc, 1833, p. 135. 



Reeve, Conch. Syst., vol. ii. pi. 233. f. 8. 



Hab. West Columbia (found in sandy mud at a depth 

 of sixteen fathoms) ; Cuming. 



Several specimens of this shell have been lately 

 brought of a dark bluish, almost ashy colour. 



Species 46. (Mus. Belcher.) 



Pleurotoma diadema. Pleur. testd conico-fusiformi, 

 subturritii. albidd, rubido-fusco ncbulosii ; anfractibus 

 convexis, inferne plicis exiguis longitudinuliter gra- 

 nulatis, superne concavis, spinis brevibus acutis uni- 

 seriatim coronutis ; sinu lato, canali longiusculo. 

 columella subumb ilica td . 



The diadem Pleurotoma. Shell eonioally fusiform, 

 somewhat turrited, whitish, clouded with reddish 

 brown ; whorls convex, lower portion longitudinally 

 granulated with small plaits ; upper portion concave, 

 coronated with a single row of short, sharp spines. 



Kiener, Icon., pi. 8. f. 2. 



Reeve, Conch. Syst., vol. ii. pi. 234. I'. 18 and 20. 



Hab. Cape Blanco, Coast of Africa ; Hinds. 



This shell is one of the most beautiful of the genus. 



