14 PROCEEDINGS OF THE NATIONAL, MUSEUM Vol. 70 



first, 18 upon the second, 22 upon the third and the penultimate 

 turn. These ribs are crossed by four strong spiral cords which are 

 a little wider than the ribs and render the axial ribs tuberculated, 

 the jfirst row of tubercles at the summit being decidedly smaller than 

 the two that succeed it. All three of these have the tubercles strongly, 

 evenly rounded. The fourth immediately above the periphery, how- 

 ever, has the spiral cord stronger than the axial ribs, and appears 

 as an almost uninterrupted cord with feebler tubercles. The pits 

 inclosed between the ribs and spiral cords are strongly impressed 

 and rounded. Suture strongly constricted, a part of the first basal 

 cord showing at the suture of the last two turns. Periphery well 

 rounded, marked by a strong spiral cord. Base moderately long, 

 marked by five spiral cords on the anterior three-fourths, which 

 become succeedingly narrower and feebler, the last two being in- 

 dicated merely by the incised lines that separate them. The anterior 

 fourth of the base is smooth, excepting incremental lines. The spaces 

 between the spiral cords on the base are crossed by fine axial threads. 

 Aperture very broadly oval ; posterior angle obtuse ; outer lip thin, 

 showing the external sculpture within, inner lip strongly curved, 

 reflected over and appressed to the base, a very narrow chink re- 

 maining behind the lip, indicating a very slight umbilicus ; parietal 

 wall covered by a thick callus. 



The type. Cat. No. 340860, U.S.N.M., was collected by Mrs. 

 Oldroyd at Cumshewa Inlet, British Columbia. It has five post- 

 nuclear whorls and measures, length, 2.T mm.; diameter, 1.2 mm. 



This species suggests Odostomia {Chrysallida) astricta Dall and 

 Bartsch from Monterey, but differs from it in being more conic, 

 with the whorls more rounded and having the base shorter and more 

 rounded, as well as in minor details of sculpture. 



ODOSTOMIA (CHRYSALLmA) TREMPERI, new species 



Plate 3, fig. 1 



Shell very elongate-conic, bluish white. Nuclear whorls at least 

 two, smooth, forming a depressed helicoid spire, the axis of which is 

 obliquely immersed in the first of the succeeding turns above which 

 a little less than half the nuclear spire projects. Postnuclear whorls 

 marked by rather strong, retractively slanting, axial ribs which are 

 a little broader than the spaces that separate them. Of these ribs 

 14 occur upon the first, 16 upon the second to fourth, 18 upon the 

 fifth and last turns. In addition to this the whorls are marked by 

 four spiral cords which render the junction with the axial ribs 

 tuberculated. The tubercules are rounded on the middle whorls 

 and slightly elongated on the last turn, the elongation correspond- 

 ing with the spiral sculpture. The spaces inclosed, between the 



