LITHODOMUS. 



Species 7. (Mus. Cuming.) 



LiTHODOMUS Antillarum. Litkod. testa cylindraccii, 

 gracili, intense castaned, in parte posticd striis per- 

 pendicular ibus fere omnino exaratd, extremitate anticd 

 posticam eeguante, margine ventrali fere rectilineo in 

 extremitate posticd ascend<Mte, dorsali subangulato, 

 umlionibM involutis, ultra extremilatem posticam prv- 

 mi/iidis. 



The West Indian Lithodomus. Shell eyiindviciil, 

 slender, dark chestnut, furrowed almost entirely on 

 the posterior portion with perpendicular strise, ante- 

 rior extremity equalling the posterior, dorsal slightly 

 angled, umboes involuted, rather protruding beyond 

 the posterior extremity. 



Modiola (Litkophagus) Antillaritm, Philippi, Zeitschrift fiir 

 Malac. 1847. 



Hab. West Indies. 



Of a very dark chestnut colour, straight in form, gently 



angularly sloping about three-fifths of the way down. 



Species 8. (Fig. a, b, Mus. Cuming.) 

 Lithodomus Cumingianus. Lithod. testa elongatd, pox- 

 tice snbglobosd, antice gradatim attenuatd, teimicid/i, 

 concentrici striatd, striis hie illic subcorruguto-plicatis ; 

 flavescente-olivaced. 

 The Cumingian Lithodomus. Shell elongated, poste- 

 riorly subglobose, anteriorly gradually attenuated, 

 rather thin, concentrically striated, stria' here and 

 there somewhat wrinkle-plicated ; yellowish-olive. 

 DuNKEE, MS. in Mus. Cuming. 

 Hab. North Australia, Mazatlan. 



A shell of light substance and pale yellowish-olive co- 

 lour, globosely formed at the posterior end, and gradually 

 attenuated towards the anterior. 



Species 9. (Mus. Cuming.) 



Lithodomus lithophaous. lAlhod. testa cylindraced, 

 castaned, in parte posticd obsolete decussatim exaratd, 

 antice concentrice rude plicald, hand attenuatd, recti- 

 lined. 



The sToNE-BoinN(i Lithodomus. Shell cylindrical, 



chestnut, obsoletely decussately furrowed on the pos- 

 terior part, anteriorly concentrically rudely plicated, 

 not attenuated, rectilinear. 

 Mytilus litlmphagus, Linnaeus, Syst. Nat. p. 1156. 



Modiola lithophaga, Deshayes. 

 Hab. Malta 



This is the well-known typical species of the genus, de- 

 scribed by Linnseus as a Mylilm, and by earlier naturalists, 

 D'Argenville, Klein, Petiver, Rumphius, Lister, and Kon- 

 deletius, as a Fhola.%. 



Species 10. (Fig. a, b, Mus. Cuming.) 



Lithodomus nasutus. Lithod. testa subcylindraced, temit, 

 kevigatd, antice concentnce plicato-striatd, margine 

 dorsali medio elevato, utrinqtie subeequaliter declivi ; 

 Jlavescente-castaned. 



The nosed Lithodomus. Shell nearly cylindrical, thin, 

 smooth, anteriorly concentrically plicately striated, 

 dorsal margin raised in the middle, nearly equally 

 sloping on each side ; yellowish-chestnut. 



Modiola udsiUa, Philippi, Abbild. und Besch. Conch, vol. 

 ii. p. 149. pi. 1. f. 2. 



Hab. Island of St. Thomas, West Indies. 



A comparatively smooth shell, frequently incrusted, as 



in Fig. 10 b, with calcareous matter which on the anterior 



side becomes decussately furrowed. 



Species 11. (Mus. Cuming.) 



Lithodomus stramineus. Lithod. testa cylindraced, 

 postice gibbd, antice latiore, rectilined, parte posticd 

 striis perpendictdaribus, hie illic divaricaiis, eximii 

 exaratd ; stramineo-caslaned. 



The straw-coloured Lithodomus. Shell cylindrical, 

 posteriorly gibbous, anteriorly broader, rectilinear, 

 posterior part delicately furrowed with perpendi- 

 cular strife which are here and there divaricate; straw- 

 coloured chestnut. 



DuxKEE, MS. in Mus. Cuming. 



Hab. West Indies. 

 There is little to distinguish this species from L. lilko- 



phagiis except its paler tone of colour, which is a character 



insufficient from its variableness. 



