18S5.] PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 283 



of the foot bifid. The northern form (his lineatus) is stated by Binney 

 to have it obtusely pointed. There is here a discrepancy worthy of 

 investigation. If the bifurcation of the foot is a merely individual vari- 

 ation or due to the infiueuce of certain localities or temperatures on the 

 specimens subjected to them and found in them only, it ought to be 

 knowuH 



The following species of Melampus are in the collection of the Na- 

 tional Museum from the western coast of America, and seem to be dis- 

 tinct from each other and from the foregoing eastern species : 



Melampiis Bridges! Carpeuter, Pauaiua. 

 Melampus trilineatus C. B. Adams, Panama. 



Melampus olivaceus Cpr., San Pedro, Cal., to Sail Diego, aud at Mazatlan. Plate 

 18, iig. 16. 



This looks toward M. lineatus Say on the one hand, and toward M. 

 coffeus on the ether. It is, however, fairly well distinguished from either. 

 There are sometimes four parietal folds beside that on the columella. 



Subgenus Leuconia Gray. 



Leuconia* Gray, Turton Man., Sded., p. 227,1840, (no descr.); P. Z. S., 1847, p. 



179 ; Tnrtou Man., 8d ed., p. 195, 1857. 

 Tohita, sp., Montague, 180:5. Pedipes, sp., Clark. 

 Jaminia, sp.. Brown ; not Eisso, 1827. 

 Ovatella, sp., Bivoua, Nnovo gen., pp. 9, 22, 1832. 

 Auricula, sp., Fdrussac. tab. Moil., p. 103; Gray, Jeffreys, &c. 

 JctcBon and Voharia, sp., Fleming, Brit. Anim., pp. 333, 337. 

 Melampus, sp., Jeffreys, Brit. Concli., v, p. 104, 1809. 

 Alexia, sp., Binney, L. aud F. W. Shells of N. Am., pt. ii, p. 4, 1865. 



Shell small, ovate; spire produced, pointed; smooth, with a thin 

 epidermis; coluuiella twisted with oue or two parietal plates, tlie ante- 

 rior much the stronger, outer lip thickened, sometimes with one denti- 

 cle on the callus ; foot subtruncate or rounded behind, transversely 

 divided at about the anterior third below. Type Voluta hidentata Mon- 

 tague. 



Melampus (Leuconia) bidentatus Montague. Plate 18, fig. 13. 



Voluia bidentaf a Monta'^ae, Suppl. Test. Br., p. 100, pi. 30, f. 2, 1803. 



Auricula micheli Mittr6, Rev. Zool., 1841, ]}. 66. 



Auricula duhia Cantraine, Bull. Brux., ii, p. 383. 



Ovatella hidentata Bivoua, Nuove Gen., p. 22, 1832. 



Auricula erosa Jeffreys, Linn. Trans., vol. xvi, p. 269. 



Melamxius l)orealis Conx&A, Am. Sourn. Sci., 2d series, sxiii, p. 345, 1833. 



Auricula denticulala Gould, Invert. Mass., p. 199, fig. 129, 1841. Not of Mon- 

 tague. 



^7exia ?»)/osof(.s Binney, L. aud F. W. Shells N. Am., part ii, p. 4, 1865. Not 

 of Draparnaud. 



Auricula Sayii Kuster in Chemnitz, Conch. Cab., ed. 2, p. 49, pi. vi, figs. 14, 15. 



Leuconia Sa>iii A. Adams, P. Z. S., 1854, p. 36, No. 2 ; Pfr. Mon. Anriculacea, p. 157. 



^ Auricula Bivonwl?h'dipin, Moll. Sicili;B, ii, p. 118, 1844. 



Melampus hidcntatu-i Jeffreys, Brit. Couch., v, p. 104, 1869, Not of Say. 



*A genns Leuconia has been erected among sponges, I believe, by Hseckel. 1 would 

 suggest for it the modified form Leuconclla. 



