54 nuculidjE. 



nentes vix declivis; postice rectiusculus, satis modice declivis; 

 ventralis integer, arcuatus, utriuque valde acclivis. Areas dorsales 

 baud definitge : postica subplanulata. — Oval, thin, much longer 

 than broad, only subventricose, with a polished greenish-olive (or 

 more rarely brownish-olive) epidermis, smooth, with at most ob- 

 solete wrinkles of increase, which are more manifest on the lunu- 

 lar region, rounded at both ends, somewhat taperingly so in front, 

 subangulately so behind. Hinder side rather elongated for the 

 genus. I'Vont dorsal edge convex, at first scarcely sloping ; hinder 

 one only moderate, straightish. Ventral margin entire, arcuated, 

 much curving up at both ends. Dorsal areas undefined, the hinder 

 one somewhat flattened. Beaks not prominent. 



26. N Stuangei, a. Adams, f. 125. — T. valde obliqua, sub- 

 ovata, longitudine latitudinem multo superante, cute uitidissima 

 aureo-virente induta, concentrice corrugata. Extreraitas postica 

 hand perbrevis (utpote Nuculm est), inferne rotundato-angulata. 

 Margo dorsabs antice primum convexus vixque declivis ; postice 

 haud repente declivis. Margo ventralis integer, arcuatus, utrinque, 

 et postice praesertim, multum acclivis. Lunula haud definita, 

 prope nates parvas rixque eminentes subimpressa ; labiis aliquan- 

 tum protrusis. Area aliquantum prominens, obsolete circum- 

 scripta. — Very obliquely subovate, much longer than broad, very 

 thin, rather compressed, with a polished pale golden-green epi- 

 dermis, and faint but regular concentric wrinkles. Anterior ex- 

 tremity well rounded, front dorsal slope at first slight and convex. 

 Posterior side not short for the geuus, liinder dorsal slope short, 

 not abrupt, but moderate, forming a rounded-ofF angle with the 

 ventral margin, which is arcuated, entire, and rises greatly on both 

 sides, but especially so behind. Lunular region undefined, some- 

 what impressed near the small and bttle projecting beaks, its Hps 

 rather pouting. Front dorsal area rather prominent, indistinctly 

 defined by a refusion. 



27. N. SIMPLEX, A. Adams, f. 137.^T. obhque ovata, longi- 

 tudine latitudinem multo superante, tenuis, subventricosa, cute 

 nitidissima olivaceo-vireute induta, intus cserulescens, vix lasvis, 

 obsolete concentrice striata. Extremitas lateris postici perbrevis, 

 inferne obsolete obtusangulata. Margo ventralis integer, multum 

 arcuatus, postice oblique acclivis. Nates acutse, haud eminentes. 

 Lunula parva, concentrice striata, inferne impresso-planulata, su- 

 perne protrusa. Area prominens, haud autem definita. — Ob- 

 liquely ovate, much longer than broad, tliin, subventricose, with a 

 polished epidermis that ranges in tint from pale to dark greenish- 



