24 ntjCuud/E. 



and front, much rising but straighter behind, subretuse before the 

 hinder extremity. Escutcheon large, angulately defined, double; 

 inner portion flattened, narrow, smooth ; outer region with indis- 

 tinct lamellar wrinkles. Lunule smooth, inconspicuous. Hinge- 

 margin broad : cartilage-pit very small, the teeth on either side of 

 it rather numerous. — Has the aspect of 2kNea.ra. The epidermis 

 is a mere iridescent film. The sculpture is occasionally obsolete ou 

 the umboes. 



40. L. cujJEATA, Soiverbi/, f. 92, 93. — T. parva, ventricosa, 

 subinsequilateralis, ovato-acuta, postice repente rostrata, cute 

 olivaceo-virescente vel olivaceo-cinerea induta, concentrice et arete 

 costellata, ad regionem solitam plicae umbonalis laevigata. Ex- 

 tremitas rostri recurvati obtuse angularis. Margo dorsalis antice 

 brevis et subdecHvis ; postice rectiusculus satisque declivis ; ven- 

 tralis antice arcuatus, postice rectior magisque acclivis. Area 

 magna, excavata, longitudinaliter tenuissime costellata. Lunula 

 nulla. — Small, beaked-ovate, ventricose, hardly even gaping at 

 the posterior tip, without conspicuous indented ray, clothed with 

 a not much shining ashy-oHve or greenish-olive epidermis, closely 

 costellated concentrically ; the riblets obsolete on the unelevated 

 site of an umbonal ridge, their intervals smooth, narrow (especially 

 below). Extremity of the somewhat shorter anterior side un- 

 symmetrically rounded : posterior side rapidly beaked, the rostrum 

 turned up, the tip bluntly angidar, nearly in or slightly above the 

 middle. Eront dorsal slope short, rather slight, straightish ; hinder 

 one moderate, upon the whole straightish, being refuse at both 

 ends, and slightly convex in the middle. Ventral margin arched 

 in front, straightish and more rising behind, without indentation. 

 No defined dorsal area in front ; the hinder one large, excavated, 

 very finely longitudinally costellated throughout, concavely im- 

 pressed at its circumference. 



41. L. ORNATA, D'Orbigni/, f. 97, 9S.— T. parva, anguste 

 ovato-acuta, postice sensim acuininato-rostrata, subinacquilateralis, 

 porca angnsta sulcoque approximato antice radiata, cute suboli- 

 vaceo-cinerea induta, costellis argutis densis subdepressis concen- 

 trice sculpta. Margo dorsalis antice subdeclivis ; postice declivis. 

 Area magna, angulatim definita, arete et tenuissime longitudinaliter 

 costellata, labiis protrusis. Lunula angusta, inconspicua. — Peaked 

 ovate-oblong, subventricose, conspicuously gaping at the hinder 

 tip, clothed with a somewhat olivaceous ash-coloured epidermis, 

 with an anterior indented ray that is flanked in front by a narrow 

 ridge or keel; most closely, finely, and evenly costellated; riblets 



