302 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 53. 



Nuclear whorls not forming a mucronate apex. 



Shell with a strong peripheral keel Scalenostoma, p. 337. 



Shell without a strong peripheral keel. 



Inner lip with a twist resembling an obsolete fold Ealiella, p. 336. 



Inner lip without a twist resembling an obsolete fold. 



Inner lip free, color bands present Eulimostraca, p. 333. 



Color bands absent Sabinella, p. 333. 



Inner lip not free, appressed to the attenuated base. 



Shell with color markings Strombi/ormis, p. 339. 



Shell without color markings. 



Shell straight Melanella, p. 302. 



Shell flexed Balds, p. 319. 



Genus MELANELLA Bowdich. 



Melanella Bowdich, Elem. Conch., vol. 1, 1822, p. 27. Type Melanella du/rcsnii 

 Bov:(lich= Eulima Risso, Hist. Nat. Eur. Mer., vol. 4, 1826, p. 123. Type 

 Eulima elegantissima Risso = Melanella polita (Linnaeus) =Balcis Leach, Syn. 

 Moll. Grt. Brit., 1852, p. 200. Type Balds arcuata Leach { = Melanella distorta 

 Jeffreys, see Jeffrey Brit. Conch., vol. 4, 1867, p. 207)~Viireolina monler- 

 osato, Nom. Conch. Medit., 1884, p. 100. Type Eulima incurva (Renier) 

 (=Melania distorta Jeffreys, see Bucquoy, Dautzenberg, and Dollfus, Mar. 

 Rous., vol. 2, 1887, p. 769). 



The genus as here constituted embraces the white poHshed mol- 

 hisks that have the last whorl produced and the inner lip appressed 

 for its entire length, or at least for the greater part of its length, to 

 the attenuated base. The shells may be straight or flexed. 



The large amount of material before us shows several species 

 which completely bridge the gap between the straight and the 

 flexed forms; the flexure in these instances being extremely slight. 

 For this reason I have combined Balds with Melanella. For con- 

 venience sake, however, rather than for difference in stnictural 

 characters, we may retain the name Balds as a group designation. 



Subgenus Melanella Bowdich. 



Melanella Bowdich, Elm. Conch., vol. 1, 1822, p. 27. Type Melanella dufresnii 

 Bowdich =JSuhma Risso, Hist. Nat. Eur. Mer., vol. 4, 1826, p. 123. Type 

 Eulima elegantissima Risso = Melanella polita (Linnaeus). 



Melanellas with straight shells. 



MELANELLA (MELANELLA) DALLI, new species. 



Plate 35, fig. 5. 



Shell straight, large, stout, polished, milk-white with irregularly 

 disposed varices. (Early whorls decollated on both of our speci- 

 mens), later whorls slightly rounded, appressed at the summit. 

 Sutures slightly constricted. Base short, well rounded. Aperture 

 oval, posterior angle acute, outer lip thin, bending slightly forward 

 immediately after leaving the summit, then backward from the 



