30 BULLETIN 91, UNITED STATES NATIONAL MUSEUM. 



MANGILIA, species? 



Cat. No. 250472, U.S.N.M., contains two young shells of a slender 

 Mangilia from Port Alfred, the nuclear whorls of which are very 

 minutely, spirally striated; the succeeding turns provided with slen- 

 der ribs and incised, spiral lines (Coll. No. 1345). 



MANGILIA, species? 



Cat. No. 19371, U.S.N.M., contains a worn specimen of a species 

 different from any of the known species. It bears the label South 

 Africa. It is too poor to be properly diagnosed. 



MANGILIA AMPLEXA Gould. 



Plate 2, fig. 10, plate 7, fig. 6. 

 Clathurella amplexa Gould, Proc. Bost. Soc. Nat. Hist., vol. 7, p. 338, 1860. 



Shell elongate-conic, white or cream-yellow. Nuclear whorls two 

 and one-half, well rounded, smooth. Postnuclear whorls strongly 

 rounded, provided with decidedly sinuous, strong, protractively 

 slanting, almost sublamellar, axial ribs, of which 14 occur upon the 

 first three and 12 upon the remaining whorls. These ribs are about 

 one- third as wide as the spaces which separate them. In addition 

 to the ribs, the whorls are marked by narrow, deeply incised, spiral 

 sulci, which are about one-third as wide as the flat spaces that sepa- 

 rate them. The increase in these sulci from the early whorls to 

 the later takes place by the intercalation of new sulci in the flat 

 spaces, which usually begin as fine incised striations. Of these 

 sulci 6 occur upon the first, 10 upon the second, 17 upon the third, 

 14 upon the fourth, and 19 upon the penultimate whorl. Periphery 

 of the last whorl well rounded. Base protracted, marked by the 

 strong continuations of the axial ribs, which become evanescent at 

 the insertion of the columella, and 23 incised spiral sulci, which are 

 a little more distantly spaced on the columella than on the posterior 

 half of the base. Aperture decidedly channeled anteriorly, poste- 

 riorly with a strong notch immediately below the suture. The type, 

 Cat. No. 217 U.S.N.M., comes from Simons Bay. It has five post- 

 nuclear whorls and measures: Length, 8 mm.; diameter, 2.5 mm. 

 Another specimen, Cat. No. 187003, U.S.N.M., comes from Port 

 Alfred (Coll. No. 535). 



MANGILIA HUMEROSA, new species. 



Plate 2, fig. 6. 



Shell slender, semitransparent, white, with a slender band of 

 bright rufous a little posterior to the periphery of each whorl and 

 sometimes a second line of the same color immediately below the 

 summit of the whorls. (Nuclear whorls decollated.) Postnuclear 

 whorls rather high between the sutures, slightly shouldered a little 



