NO. 2207. WEST AMERICAN MELANELLID MOLLUSKS—BARTSCn. 319 



altitude. The whorls are united by a simple suture, which may be 

 called a very clearly and feebly impressed line. The aperture is 

 slightly oblique, and cordate; its margins are smoothly united at the 

 base by a curve which marks the greatest width. Though not sharp, 

 the margins are scarcely at all thickened, the left margin enlarging a 

 little in order to spread out over the side of the last whorl and over 

 the columella, which is enlarged somewhat and seems to be reflected. 

 On certain days Eulirmi elodia, which is milky-white, seems to be 

 almost opaque. Nevertheless it is brilliantly polished and rather 

 diaphanous, so that a certain direction of the light may make all the 

 details of the interior structure apparent, and give to it the appear- 

 ance of a double suture. It may be said that the true suture is a white 

 ribbon, more strongly marked than that which is posterior to it, and 

 which exactly simulates it. By following this ribbon, at the same 

 time the suture, as far as the angle of the aperture on the final whorl, 

 the illusion will be naturally dissipated. 



" Type locality. — Negritos; or Margarita Island, Panama." 

 I have not seen specimens of this species and quote the description 

 and figure. 



Subgenus Balcis Leach. 



Balds Leach, Syn. Moll. Grt. Brit., 1852, p. 200. Type Balcis arcuata Leach. 

 (=Melanella distorta Jeffreys, see Jeffrey Brit. Conch., vol. 4, 1867, p. 207.) 

 =^Vilreolina Monterosato, 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. 



Melanellas with flexed shells. 



MELANELLA (BALCIS) DRACONIS, new species. 



Plate 39, fig. 2. 



Shell short, very broadly conic, milk-white, flexed in one direction 

 only. The tip of our shell is broken. The first two whorls remain- 

 ing are slightly rounded, the rest almost flat. Suture well marked. 

 Last whorl rather stout. Periphery decidedly angulatcd. Base 

 short, somewhat tumid anteriorly, well rounded. Aperture broadly 

 oval; posterior angle acute; outer lip decidedly sinuous, strongly 

 protracted in the middle, to form a decidedly claw-like clement; 

 inner lip stout, strongly reflected over and appressed to the base; 

 parietal wall covered by a rather thick callus. 



The type (Cat. No. 215766 U.S.N.M.) comes from Dead Man's 

 Island, California. It has seven and a half whorls remaining, and 

 measures — length, 6.1 mm.; diameter, 2.7 mm. This fossil species 

 is the stoutest of the single curved Eulimellas known from the west 

 coast of America. 



