SIGARETUS 



Plate I. 



Genus SIGARETUS, Adanson. 



Tenia depress^ oriiciilaris vel aiiriformis, nunquam umbili- 

 cata, spird parva, Lrevi, inlerdum plano-immerm, an- 

 fractibiis pUrnmque quatuor, iiUimo perampUter injluto, 

 srppimme spirnliter inclso ; npertitra inflatd, columMd 

 ttnue callosii-rtflexd . 



Shell depressly orbicular or ear-shaped, never umbilicated, 

 spire small, short, sometimes flatly immersed, whorls 

 generally four, the last very largely inflated, mostly 

 spirally incised ; aperture inflated, columella thinly 

 callously reflected. 



Sigaretus is a moUusk of comparatively large size, en- 

 closing an ear-shaped shell over the branchial and visceral 

 portion of the body, within the embrace of two capacious 

 lobes of the mantle. The shells are therefore for the most 

 part without colour. In one or two species, where the 

 shell is large and less enveloped by the animal, it par- 

 takes of an ash-brown colour, tinged with livid-violet 

 towards the apex, and is covered by a thin, horny epi- 

 dermis. The only kind of sculpture which the shell pre- 

 sents is in the form of spiral, ridge-like stripe, mostly 

 incised in the interstices. 



Between thirty and forty species of Sigaretns have been 

 described, but as far as my own observations go, I can- 

 not define more than the following twenty. six, including 

 Sigaretus papilla and its allies, contained in PI. IV. and 

 v., an umbilicated form of the genus, of w Inch a separate 

 group has been constituted with the title Naticina. 



Of the sixteen Sigareti proper, the largest and most 

 conspicuous species, S. concavua, is a native of the shores 

 of Peru ; this, and four species of smaller size inhabit- 

 ing the West Indies and southern shores of North America, 

 being all that have been collected in the western hemi- 

 sphere. The remaining eleven species, inhabiting the 

 eastern hemisphere, are distributed as follows. Six are 

 natives of the islands of the Eastern Archipelago, two are 

 from Malacca, two from Australia and Tasmania, and one, 

 the original Sigaret of Adanson, from West Africa, this 

 last species being of the same solid, subglobose type as 

 the Pernvian 5. coiicacns. The Naticina species range 

 from Japan to Australia and New Zealand. 



spird vix exsertd, avfi-actibiia subventricosis, apiraliter 

 midaio-striatis, striis suhpi'ominentibits, concentrici ar- 

 cuato-plicatis ; seniipellucido-alba. 



The smooth Sigaretus. Shell ovate, convexly de- 

 pressed, spire scarcely exserted, whorls rather ventri- 

 cose, spirally wave-striated, striffi rather prominent, 

 concentrically arcuately plicated ; semitranspareut- 

 white. 



Pecluz, Illus. Conch. Sig. p. 16. pi. 3. f. 9, 10. 



Hab. Island of Luzon, Philippines (in sandy mud, at a 

 depth of seven fathoms) ; Cuming. 



A semitransparent, concavely depressed shell, in which 

 the spiral striae have almost the force of ridges, and are 

 prominently waved. 



Species 1. (Fig. a, b, Mils. Cuming.) 

 Sigaretus l.evigatus. Sig.tesidovatd, convexo-depressd. 



Species 2. (Fig. a, b, Mus. Cuming.) 



Sigaretus Mabtixianus. Sig. testa ovato-am-iformi, 

 convexe curvatd, soUdinsculd, spird parvd, parum ex- 

 sertd, anfractibus circa spiram concavo-impressis, spi- 

 raliter midato-striatis, striis plus 'minus obsoletis, cou- 

 centriee irregulariter plicato-corriigatis ; rufescente- 

 fuscd. 



JIaetini's Sigaretus. Shell ovately ear-shaped, con- 

 vexly curved, rather solid, spire small, but little ex- 

 serted, whorls concavely impressed round the spire, 

 spirallv wave-striated, strife more or less obsolete, 

 concentrically irregularly plicately wrinkled, i-eddish- 

 brown. 



PlilLiPi'l, Abbild. und Besch. Conch, vol. i. p. 1-t-t. Sig. 

 pi. 1. f. 5. 



]{,ih. Island of St. Thomas, AVest Indies. 



Distinguished from all other species of the genus by 

 its peculiar red-brow-n colour. M. Eecluz regards it as a 

 variety of S. maculalus, but the shell is difterent in form, 

 concavely impressed around the spire, more ear-shaped 

 and more strongly plicately wrinkled. 



Species 3. (Fig. «, b, JIus. Cuming.) 

 Sigaretus concavus. Sig. testa gluboso-aurifurmi, ob- 

 tuse conicd, spird parum exsertd, anfractibus declivi- 

 ventricosis, spiraliler plano-liratis, liris laiis, inler- 

 stiliis angustis, iucisis, epidermide plus minus indntis ; 

 cinereo-fuscescente, spird livido-violaced, iiitus nitente 

 rufescente-caslaned. 



Julv, ISiH. 



