162 BULLETIN 68, UNITED STATES NATIONAL MUSEUM. 



last whorl marked In' a spiral cord. Base attenuated, marked by 

 six equally spaced spiral cords and slender axial tlireads in the 

 grooves between the cords. Aperture oval; posterior angle acute; 

 outer lip thin, showing the external scuh^ture within; columella 

 moderately strong, slightly curved, provided wdth a strong fold a 

 little below its insertion. 



De Folin's type comes from Margarita Island, Bay of Panama. 

 It has five post-nuclear whorls and measures: Length 3.6 mm., 

 diameter 1.5 mm. De Folin's figure, w^hich we copy, not having 

 seen any specimens of this species, is inconsistent, in showing fiive 

 spiral cords on the second and third whorls. 



ODOSTOMIA (CHRYSALLIDA) DEFOLINIA CONTRACTA de Folin. 



Noemia angusta var. contracla de Folin, Fonds de la Mer, vol. 2, 1872, p. 165. 



Of this form de Folin says:'^ "Shell similar to Noemia angusta but 

 smaller, less ventricose, and more oval; length 3 mm., diameter 

 1.2 mm." 



ODOSTOMIA (CHRYSALLIDA) DEFOLINIA DIFFICILIS, new name. 



=Noemia angusta var. ovata de Foun, Fonds de la Mer, vol. 2, 1872, p. 165; not 

 Chrysallida ovata Carpenter, 1856. 



Of this form de Folin says:^ "Shell similar to Noemia angusta 

 but smaller, with a spire more ovate, and the whorls more convex; 

 aperture broader; outer lip crenulate; columella less expanded; 

 length 2.7 mm., diameter 1.3 mm." 



ODOSTOMIA (CHRYSALLIDA) OREGONENSIS Dall and Bartsch. 



Plate 17, figs. 3, 3a. 



Odostomia (Chrysallida) oregonensis Dall and Bartsch, Proc. U. S. Nat. Mus., 

 vol. 33, 1907, pp. 516, 517, pi. 46, figs. 10, 10a. 



Shell elongate-conic, slender, subdiaphanous to milk-wliite. Nuclear 

 whorls immersed, the last one only being visible. This is some- 

 what tilted and marked by tlu-ee strong narrow spiral keels and 

 many slender raised axial threads which cross the grooves between 

 the keels. Post-nuclear whorls well rounded, slopingly shouldered 

 at the summit and separated by constricted sutures, ornamented by 

 almost equal and equally spaced spiral keels and axial ribs between 

 the sutures on the spire. There are 4 spiral keels on the first, sec- 

 ond, and third whorls, 6 on the fourth, and 7 upon the penultimate 

 whorl. The first of these keels is on the shoulder of the whorl near 

 the summit and is somewhat less developed than the rest. The axial 

 ribs are best developed on the early whorls, where they extend 

 equally strong from the summit to the periphery ; on the antepenul- 



a Fonds de la Mer, vol. 2, 1872, p. 165, 



