PLEUROTOMA. 



Plate I. 



Genus Pleurotoma, Lamarck. 



Test a turrita , fusiformis , spird acuminatd; columella lavi, 

 in canalem rectum nunc elongatum, nunc breviuscu- 

 lum, desinente ; aperturd ovali, lubro simplici, acuta, 

 post ice siiiu fissurdve emarginato. Operculum cor- 

 nevm, infra acuminatum. 



Shell turrited, fusiform, spire acuminated ; columella 

 smooth, ending in a straight canal, varying con- 

 siderably in length ; aperture oval ; lip simple and 

 acute, emarginated at or near its junction with the 

 last whorl with either a slit or fissure. Operculum 

 horny, acuminated at the lower end. 



The Pleurotoma; were separated by Lamarck from the 

 fusiform portion of the Linnaean Murices, originally di- 

 stinguished by Bruguiere with the title of Fusus. The 

 labral slit or sinus which has been selected to charac- 

 terize this genus is a never-failing mark of distinction, 

 for after an examination of nearly two hundred species 

 now before me, exhibiting this peculiarity in every con- 

 ceivable variety of form, I come to the conclusion that 

 the genera into which some authors have thought it ex- 

 pedient to distribute them (Clavatula, Drillia, Melatoma, 

 Perronia, e. g.) might be profitably dispensed with. 



Species 1. (Mus. Stainforth.) 



Pleurotoma cingulifkra. Pleur. testd turrito-subulatd, 

 transversim striatd, sulcata et cingulatd ; anfractibus 

 convexiusculis, prope suturas cingulo unico circiim- 

 vallatis; cingulo maculis quadratic rufis pictoj canali 

 brevi, recurvo ; labro margine scubro. 



The girdled Pleurotoma. Shell turrited, acuminated, 

 transversely striated, grooved and belted ; whorls 

 rather convex, surrounded with a single girdle or 

 belt near the sutures, painted with square reddish 

 spots ; canal short and recurved ; lip rather rough 

 at the edge. 



Lamarck, Anim. sans vert., vol. vii. p. 94. 



Kiener, Iconographie, pi. 17. f. 1. 



Hab. Coast of Madagascar, Red Sea, Philippines, &c. 



The belt or girdle which is formed round this shell 

 by the filling up of the marginal slit is peculiarly paint- 

 ed with a regular series of square, equidistant, reddish 

 brown spots. The canal is short, and somewhat twisted. 



Species 2. (Mus. Stainforth.) 



Pleurotoma variegata. Pleur. testa turrita, fusiformi, 

 griseold, fusco-maculatd, lineis undulatis longiludina- 

 literpicld : anfractibus convexis, transversim sulcatis, 

 obscure granoso-striatis, si/perne zond bicarinatis .• 

 spird elongatd, acuta; canali ad basin subftexuosd. 



The variegated Pleurotoma. Shell turrited, fusiform, 

 greyish, brown spotted, and painted longitudinally 

 with undulated lines ; whorls convex, transversely 

 sulcated, obscurely grained and ornamented round 

 the upper half with a double zone or belt ; spire 

 rather elongated and acute ; canal rather flexuuus 

 at the base. 



Kiener, Iconographie, pi. 0. f. 1. 



Hab. Indian Ocean, Kiener. 



Kiener appears to have been the first to notice the 

 specific peculiarities of this shell. It is of a pale grey- 

 ish colour, variegated with numerous granular spots of 

 reddish brown, ranging in the form of stria; and longi- 

 tudinal streaks. 



Species 3. (Mus. Stainforth.) 



Pleurotoma tigrina. Pleur. testd fusiformi-turritu. 

 mu/ticarinatii. a/bido-grised, nigro-punctatd, striis 

 transversis, tenuissime granulosis, ornatd ; anfracti- 

 bus convexis, medio bicarinatis ; canali longiusculo. 



The tiger- spotted Pleurotoma. Shell fusiform and 

 turrited, many-keeled, of a greyish white colour, 

 more or less spotted with black and ornamented 

 with very finely granulated transverse strife ; whorls 

 convex, doubly carinated round the periphery ; 

 canal rather long. 



Lamarck, Anim. sans vert., vol. vii. p. 9."). 



Kiener, Iconographie, pi. 8. f. 1. 



Hab. Philippine Islands (sandy mud, seven fathoms). 



Few species exhibit a greater variety of growth and 

 marking than this ; the periphery of the whorls is never- 

 theless constantly prominent and acute, and it is pecu- 

 liar in being doubly carinated. 



Species 4. (Mus. Stainforth. ) 



Pleurotoma Garnonsm. Pleur. testa elongato-turritd, 

 gracillime fusiformi, albidd, transversim multicari- 



Jan. 1843. 



