176 BULLETIN 68, UNITED STATES NATIONAL MUSEUM. 



Subgenus MIRALDA A. Adams. 



Miralda A. Adams, Jour. Linn. Soc. London, vol. 7, 1864, p. 3. + Lia de Folin, 

 Fonds de la Ikler, 1870, p. 515. Type, Lia decorata de Folin. -\-Ividia Dall 

 and Bartsch, Proc. Biol. Soc. Wash., vol. 17, 1904, p. 11. Type, Parthenia 

 armata Carpenter. 



Odostomias with very strong spiral keels between the sutures and 

 on the base; the anterior one of which, and sometimes the one next 

 to it, strongly crenulate; the remainder simple and acute. Base 

 axially lirate. 



Type. — Parthenia diadema A. Adams. 



KEY TO THE SPECIES OF THE SUBGENUS MIRALDA. 



Spiral keels between the sutures 3 hemphilli, p. 176. 



Spiral keels between the sutures 2. 

 Base with 3 spiral cords. 



Posterior keel between the sutures much wider than its neighbor .armada, p. 177. 

 Posterior keel between the sutures not wider than its neighbor. 



Spiral keels between the sutures almost smooth exarata, p. 177. 



Spiral keels between the sutures nodulose terebellum, p. 177. 



Base with two basal cords. 



Shell stout xpynota, p. 178. 



Shell slender galapagensis, p. 179. 



ODOSTOMIA (MIRALDA) HEMPHILLI, new species. 

 Plate 19, fig. 10. 



Shell broadly conic; milk-white. Nuclear whorls deeply obliquely 

 immersed, apparently smooth. Post-nuclear whorls well rounded, 

 marked with three strong, equal spiral keels, the posterior two of 

 which are tuberculatc, the third one smooth. The tubercles are con- 

 nected axially by slender riblets, which extend to the third keel. 

 There are about twenty tubercles on the latter whorls, while on the 

 early whorls they are ill defined. Sutures deeply channeled. Periph- 

 ery of the last whorl marked by a smooth spiral keel, equal to the one 

 posterior to it. Base moderately long, well rounded, marked by four 

 spiral keels- which grow successively weaker anteriorl3^ Aperture 

 irregularly ovate; posterior angle obtuse; outer lip thin, showing the 

 external sculpture within; columella stout, provided with a strong 

 fold at its insertion. 



The type (Cat. no. 162841, U.S.N.M.) was collected at San Hipolito 

 Point, Lower California. It has six post-nuclear whorls and meas- 

 ures: Length 3.5 mm., diameter 1.4 mm. Another specimen from 

 the same locality is in Mr, Henry Hemphill's collection. Cat. no. 

 162842, U.S.N.M., one specimen from San Pedro, California. One 

 specimen from Point Abreojos, Lower California, Cat, no. 106498 

 U.S.N.M. 



Named for Henry Hemphill. 



