L I T H DO M U S. 



Species 18. (Miis. Cuming.) 



LiTHODOMUS EUGIFERUS. Litlwd. testd cylindraced, te- 

 nui, convexd, extremitalibus snhtequaliter rotimdatis ; 

 Jlavescenie-castaned, parte posticd crustd calcared d&tsi' 

 rugiferd. 



The wrinkled Lithodomus. Shell cylindrical, thin, 

 convex, extremities nearly equally rounded ; yellow- 

 ish-chestnut, posterior part with the calcareous crust 

 densely wrinkled. 



DuNKER, MS. in Mus. Cuming. 



Hab. ^- ? 



A shell of rather slight substance, incrustcd with a 

 wriiikk'-roughened calcareous coating. 



Species 19. (Mas. Cuming.) 

 Lithodomus Hanleyanus. Lithod. kdd parvimculd, 



rottmdato-cylindraced, ienuissimd, mdici subexcavald 



et rngvlosd. 

 Hanley's Lithodomus. Shell rather small, rotundately 



cylindrical, very thin, anteriorly slightly excavated 



and rugidose. 

 DuNKER, MS. in Mus. Cuming. 

 JIah. Suez. 



In this very slight species the wrinkled sculpture of the 

 calcareous coating is at the anterior end. 



Species 21. (Mus. Cuming.) 

 Lithodomus appendiculatus. Lilhod. kdd mdjcyHn- 

 drucm, IrEvic/ald, postire ruhindidu, nnlirc nUninciti'i, 



area superi.ore utrinqiip cxcavald, appfiidic/bm Mediu- 

 ms prominuUs. 



The appendaged Lithodomus. Shell nearly cylindri- 

 cal, smooth, posteriorly rounded, anteriorly attenu- 

 ated, upper area excavated on both sides, the middle 

 appendages being rather prominent. 



Modiola appendicidata, Philippi, Abbild. and Bcsch. Conch, 

 vol. ii. p. 150. pi. 1. f. 4. 



Ilab. Cuba. 



Characterized by an excavation running on each side, 

 from the ligamentary area to the anterior extremity, wliieh 

 produces a raised wing-like prominence in the centre. 



Species 20. (Mus. Cuming.) 



Lithodomus Malaccanus. Lithod. testd parviusculd, 

 lenui, angusie cylindraced, postice rotmulatd, antice 

 attenuatd et rugoso-exaratd. 



The Malacca Lithodomus. Shell rather small, thin, 

 narrowly cylindrical, posteriorly rounded, anteriorly | 

 attenuated and wrinklc-furrnw<'(i. j 



Hab. Malacca. i 



Of rather narrower cylindrical form than the preceding 



species, conspicuously attenuated and wrinkle-furrowed at 



the anterior end. 



Species 32. (I'ig. «, b, Mus. Cuming.) 



JjIthodomus bi-excavatus. Lithod. testd cylindraced, 

 naviformi, postice convexd, Iceviijatd. antic}: hiradialim 

 angulato-excavatd, rugosd. 

 The doubly-excavated Lithodomus. Shell cylindri- 

 cal, boat-shaped, posteriorly convex, smooth, anteri- 

 orly biradiately angularly excavated, rough. 

 Hab. Island of St. Thomas, West Indies. 



Very closely allied to the preceding species, but of ra- 

 ther different form, more decidedly excavated down each 

 anterior slope, though the upper middle portion of the 

 valves is less prominent. 



Species 23. (Mus. Cuming.) 

 Lithodomus plumula. Lithod. testd ehngato-ryUndra- 

 ced, postice rotundatd, leevigatd, antice attenuatd, pc- 

 cidiariter ngoso-plumulatd. 

 The fe.\ther Lithodomus. Shell elongately cylindri- 

 cal, posteriorly rounded, smooth, anteriorly attenu- 

 ated, peculiarly roughly feathered. 

 Hanley, Pro. Zooi. Soc. 1841, p. 17. 

 Hab. Panama (found imbedded in Spomlyli) ; Cuming. 



This species is especially curious in showing the fea- 

 thery disposition of the incrustation on the anterior 

 slope. 



Species 24. (Mus. Cuming.) 

 )MUs pessulatus. Lithod. testd cylindraced, pos- 



rolinidatd, ontice deciiri-ottennntu. parte pnslicd 



()ctol)( 



