PLEUROTOMA. 



Plate XII. 



Species 98. (Mus. Cuming.) 



Pleurotoma astricta. Pleur. testa cylindracco-oblongd, 

 spiraliter sulcatd; anfractibus convexis, pallide lu- 

 teolis, tricarinulatis, carinulis subobsoletis, carinuld 

 media rubido-fusco alboque articulato eximie astrictd ; 

 aperturd canalique brevibus. 



The laced Pleurotoma. Shell cylindrically oblong, 

 spirally grooved ; whorls convex, pale yellow, tri- 

 carinated, keels almost obsolete, middle keel deli- 

 cately laced with an articulated chain of white and 

 reddish brown ; canal and aperture short. 

 Pleurotoma interrupta, Sowerby, Pro. Zool. Soc, 

 1833. 



Hub. Island of Annaa (Chain Island), found under coral 

 on the reefs ; Cuming. 



I impose a new title upon this species in consequence 

 of the word interrupta having been pre-occupied by La- 

 marck. It is at present unique in Mr. Cuming's col- 

 lection. 



Species 99. (Mus. Cuming.) 



Pleurotoma cincta. Pleur. testa ovato-subcylindraced, 

 fulvd, apice subulato-pyramidali ; anfractibus trans- 

 versim bicarinulatis, carinuld crenatd interveniente, 

 anfractu ultimo carinato per tolum ; aperturd canali- 

 que brevibus. 



The encircled Pleurotoma. Shell ovately cylindrical, 

 yellow, apex subulately pyramidal ; whorls encir- 

 cled with two rounded keels with a very fine cre- 

 nated or beaded keel running between, last whorl 

 keeled throughout ; canal and aperture short. 



Lamarck, Anim. sans vert., vol. vii. p. 92. 



Pleurotoma modesta, Sowerby, Pro. Zool. Soc, 1833. 



Hab. Real Llejos and Island of Annaa (dredged from 

 sandy mud at the depth of eight fathoms) ; Cuming. 



After carefully examining the identical shells de- 

 scribed by Lamarck and Sowerby under the respective 

 titles of cincta and modesta, I am unable to discover any 

 specific ditf'crence between them. 



Species 100. (Mus. Cuming.) 



Pleurotoma aterrima. Pleur. testd acuminato-pyrami- 

 dali, aterrimd ; anfractibus superne unicarinatis, ca- 

 rind prominente infrd crenulatis; anfractu ultimo serie 



unicd. mediand nodulorum, infrd seriebus duabus gra- 

 nularum ornato ; sinu latiusculo ; canali brevissimo. 



The very black Pleurotoma. Shell acuminately 

 pyramidal, very black ; upper part of the whorls 

 encircled with a single prominent keel, lower por- 

 tion crenulated, last whorl ornamented with one 

 row of nodules and two rows of granules ; sinus 

 rather broad ; canal very short. 



Sowerby, Pro. Zool. Soc, 1833. 



Hab. Monte Christi, West Columbia (found under 

 stones) ; Cuming. 



This species may be easily recognised by the rude 

 blunted keel which spirally entwines the shell. 



Species 101. (Mus. Deshayes.) 



Pleurotoma pluteata. Pleur. testd fusiformi, gracili, 

 fulvd; anfractibus convexis, pluteo superne ornutis, 

 medio nodulis albidis catenulatis, infra subtilissime 

 sulcatis ; sinu lato ; canali elongato. 



The shelved Pleurotoma. Shell fusiform, slender, 

 yellowish ; whorls convex, upper part ornamented 

 with a kind of shelf or parapet, middle delicately 

 chained with whitish nodules, lower portion very 

 finely grooved ; sinus broad ; canal long. 



Reeve, Pro. Zool. Soc, 1S43. 



Hab. ? 



The shelf which passes round the upper portion of the 



whorls is not less characteristic of this species than the 



delicate chain of white nodules which encompass the 



centre. 



Species 102. (Mus. Cuming.) 



Pleurotoma nigerrima. Pleur. testa acuminato-pyra- 

 midali, nigerrimd ; anfractibus superm- planulatis, 

 prope suluram subnodosis, infrd transversim concinn'i 

 striatis, longitudinaliter costatis, costis arcuatis, sub- 

 distantibus; aperturd oblongd, superne callositate mu- 

 nitd ; canali longiusculo, subrefe.ro. 



The jet-black Pleurotoma. Shell acuminately pyra- 

 midal, jet-black ; upper part of the whorls flat, 

 slightly knobbed near the suture, lower portion 

 finely striated transversely, ribbed longitudinally, 

 ribs curved and rather wide apart ; aperture ob- 

 long ; canal rather long and a little reflected. 



Sowerby, Pro. Zool. Soc, 1833. 



May 1843. 



