2. _N. Mejicanus._ All wings are occupied with it, till beyond the second band, where the brownish coloration of the margin begins. Bands and spots perfectly white. 3. _N. Virgulti._ Extension of the fulvous as in the preceding, but all the space more or less occupied by black. Middle band nearly altogether fulvous, other bands and spots white. As much as we know, the type of this genus _N. Lucina_ L, was the only species known heretofore, and it is another proof of the various repetition of types on occidental coasts, that we have to add three Pacific representatives of a genus first discerned in a single European species. The group of the _Erycinides_ belongs essentially to tropical America. The beforementioned _Nemeobius Lucina_ is the only European representative of this numerous and polymorphous group. Besides this, there exist some few Asiatic members of this family, very aberrant in their type, scarcely known and insufficiently examined, so that possibly they may belong somewhere else. In America the tropical genera _Nymphidia_ and _Lemonias_, extend beyond the Cancer on the Atlantic side; but on the Pacific side reappears the European genus _Nemeobius_, extending into the Tropics, and seems to find here its very centre. Description of New Species of Land Shells. BY W. NEWCOMB, M.D. _Helix Blakeana_, Newc. Hel. testa unicolor flavido-alba, rotundato, semi-globosa, nitida, translucida; umbilico amplo, profundo et parum obtecto; apice obtuso; anfractibus sex, convexis, tribus superioribus sub-planis, reliquiis rapide accrescentibus, ultimo inflato; sutura bene impressa; aperturâ rotundato-lunare; peristomate tenue, ex panso-reflexo cum columellâ sub-late dilatatâ, non adnatâ. Alt. ·7 pol., Diam maj. 1·1 pol., min. 1· pol. Hab. Insula Niphon—Japan, (teste Blake). Shell uniformly yellowish white, rounded, half globular, shining, translucent; umbilicus large, deep and slightly covered; apex obtuse; whorls six, convex, the three first nearly on the same plane, the balance rapidly increasing, the last swollen; suture well marked; aperture roundly lunar; lip thin, flatly reflected, at the columella broadly dilated but not adherent. NOTE.—In general form and color, this species makes a nearer approach to _H. candida_, Moricand, than to any species with which I am acquainted. It varies in the less elevation, in the form of the spire, and in some other respects. Professor Blake had remarkable facilities for collecting in Japan, but unfortunately the mice proved so destructive to his terrestrial shells, as to leave him but few specimens as the result of his labor. _Helix declivis_, Newc.