NUCDUDjE. 



55 



olive ; scarcely smootli, the faint strife of growth being here and 

 there almost regular. Anterior extremity «'ell rounded, front 

 dorsal slope at first sliglit, convex. Ventral margin entire, much 

 arcuated, rising obliquely behind, forming a rather obscure obtuse 

 angle with the abrupt slope of the very short posterior side. 

 Beaks acute, not prominent. Lunule small, concentrically striated, 

 tlatly impressed below, pouting above. Front dorsal area not de- 

 fined, but prominent. Nacre bluish. 



28. N. CONVEXA, Sowerbi/, f. 112, 113.— T. oblique ovata, 

 longitudine latitudinem multo superante, valida, conceritnce cor- 

 rugato-subplicata. Latus posticum hand perbrevis, fere m medio 

 angulatum. Margo dorsalis anticus prope nates prominentes rec- 

 tiu^culus vixque declivis, deinde curvatus satisque declms; 

 posticus brevis, demum retnsus. Margo ventralis integer, multum 

 arcuatus, postice notabiliter obhque acclivis. Lunula brevis, satis 

 circumscripta, planulato-impressa, cordata. Area fere inconspicua. 

 Mai-o-o cardinalis latus : deutes circiter 22-7 : cartilago subhori- 

 zontalis.— Obliquely ovate, much longer than broad, strong, sub- 

 pliciformly corrugated concentrically. Anterior side rounded at 

 the extremity (sometimes a little taper) ; its dorsal slope at first 

 straightish and nearly horizontal, then curved and moderately 

 sloping. Posterior side not short for the genus, subcentrally an- 

 gulated, its dorsal slope short, not very abrupt, eventually retuse. 

 Ventral margin entire, much arched, very conspicuously slanting 

 upwards behind. Umboes prominent. Lunular area tolerably 

 defined, flatly impressed, short, cordiforra. Front dorsal area a 

 little indented, undefined. Hinge-margin broad ; cartilage sub- 

 horizontal : teeth little raised, about twenty-two and seven (m the 

 a-'ed), very close, wide, and obtusangular.— The epidermis of the 

 adult is unknown, but it is cinereous and shining in the fry, 

 which is at that stage smooth, with its lunule projecting in the 

 middle.* 



29. N. ANTIPODUM, Hanleij, f. 155.— T. valde obliqua, ellip- 

 tica, postice recte truncata, antice rotundato-attenuata, maxime 

 inffi'quilateralis, valida, subventricosa, Isevis, cute nitida pallide 



* In the ' Proceedings of the Boston Society of Natural History ' (ii. p. 100), Dr. 

 Gould refers to .V. tumida of Reeve (? a slip of the pen) as resembling his— ^ 



N TURGiDA— "T alba, suba^quilateralis, subrhoniboidea, postice acuta, auticero- 

 tundata, ventricosa, margine veutrali pendente, ubique lamellis coiieentrieis obtusis 

 reflexis confertis omata : natibus prominentibus ; cardine dentibus 21 utroque latere 

 instructo -i-i " No locality is mentioned, but the descnption is included in his 

 account of Tavoy land and fresh-water shells. From the dentition and lamellation 1 

 sliould have thought it a Lerh rather than a Ktimlif^ 



