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Nerita crassa. T. solidissima, subglobosa, longitrorsum striata. 

 spiraliter sulcatoeostata (costis ad 30 rotundatis) fusco-cinerea, flam- 

 mulis crebris angulatis obliquis variegata : spira prominula, ad apicem 

 lutea ; anfr. 4 rotundatis ; sutura impressa : apertura parva, semi- 

 circularis ; labro crassissimo, aneiso, crenulato, intus sulcato, postice 

 unidentato ; labio angusto, 8-plicato, plicis anticis bisectis ; columella 

 bidentata, dente antico minimo. Diain. 1 ; axis, -| poll. 



This is probably the most solid of all the Nerites. The variations 

 in this genus are so numerous as to render specific distinctions doubt- 

 ful. This is allied to N~. Guillouana and N. undulata. The lip, number 

 of teeth, and sulci and form of ribs differ from the former ; the ele- 

 vated spire, finer ribs, rugose column, and protruding Up characterize 

 the latter. 



Margarita Magellanica. T. depresso-conica, solida, imper- 

 forata, polita, rufa interdum sordide flavescens : anfr. 5-6 convexis, 

 ultimo ad peripheriam sub-angulato : basis tumida : apertura ampla, 

 subcircularis ; columella rotundata vix arcuata angulum basalem cum 

 labro efformante: faux vivide iridescens. ;Axis, -| ; diam. f poll. 

 Orange Harbor, Tierra del Fuego. Couthouy. 



It varies in being of a paler color, smooth surface, less angular 

 periphery and by having vestiges of epidermis. 



Margarita Persica. T. parva, solida, depressa, ovato-conica, 

 levigata, nitida, intense purpureo-incarnata : anfr. 5 convexiusculis, 

 superne declivibus, ad suturam confluentibus : basis convexa, medio 

 indentata, pallida; columella lata, excavata, arcuata: apertura cir- 

 cularis : faux vivide iridescens. Diam. \ ; axis, T 3 g poll. From 

 among Cape Horn Shells. 



Remarkable for its excavated, crescentic pillar, much as in Lacuna ; 

 in this it differs chiefly from the last species. 



Purpura ostrina. T. solida, rudis, rotundato-ovata, patula, 

 exalbida, purpurascens interdum fasciis geminatis rubidis cincta : 

 spira brevis, conica ; anfr. 4-5 obtuse angulatis, convexis, ultimo am- 

 plissimo, ventricoso : apertura rotundata-ovalis, livido-tincta ; labro 

 simplici patente ; columella explanato-planulata ; sinu siphonali an- 

 gusto, minime profundo, brevi. Long. 1 ; diam. f poll. Obtained at 

 Killimook, Oregon. 



Allied to P. lapillus and Freycineii, distinguished by its smoothish 

 surface, coloration, large and patulous aperture and flattened colu- 

 mella. 



Nassa lilactna. T. ovato-conica, levigata, lilacina ; spira acuta, 

 anfr. 7-8 convexis, ad suturam crenulatis, supernis plicatis et striis 

 volventibus cinctis, ultimo dimidiam longitudinis testaa adequante ; 

 basi spiraliter striata : apertura lunata ; labro simplici ; sinu siphonali 



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