68 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 50. 



interspaces and an occasional intercalary smaller thread; they do not 

 nodiilate when they cross the ribs; on the canal are numerous small 

 close-set threads; the anal fasciole is without spiral sculpture; axial 

 sculpture of (on the last whorl 13) strong rounded ribs not continu- 

 ous up the spire and obsolete on the base but prominent and arcuate 

 over the fasciole. reaching the preceding suture which they undulate ; 

 aperture rather narrow, the anal fasciole at the suture, shallow and 

 wide, the outer lip thin, moderately produced, the inner lip smooth, 

 erased ; pillar short, straight, attenuated in front, canal short but dis- 

 tinct. Height of shell, 13 ; of last whorl, 8 : diameter, 5 mm. Cat. 

 No. 208560, U.S.N.M. 



Range. — Granite Cove, Port Althorp, Alaska, in about 10 fathoms, 

 gravel ; W. H. Dall. 



MANGILIA ALTHORP!, new species. 



Plate 19, fig. 9. 



Shell small, waxen white, superficially resembling M. granitica 

 Dall but differing in the following particulars: It has one rib less; 

 the two prominent spiral cords on the early whorls are strongly 

 nodulous when they cross the ribs, especially the posterior cord, even 

 on the last whorl ; the spiral sculpture on the last whorl in front of 

 the fasciole comprises 10 strong flattish cords, separated by very 

 sharp, narrow grooves, with no spiral sculpture on the back of the 

 canal, which is distinctly shorter; aperture relatively shorter and 

 wider; the nucleus apparently similar but eroded, the number of 

 whorls is the same but the shell is shorter. Height of shell, 11.5 ; of 

 last whorl, 6.5 ; diameter, 4.5 mm. Cat. No. 208560a, U.S.N.M. 



Range. — Station 1413, Granite Cove, Port Althorp, Alaska, in 

 about 10 fathoms, gravel, W. H. Dall. 



MANGILIA CARLOTTAE. new species. 



Plate 21, figs. 9, 12. 



Shell small, thin, snow white, with a swollen smooth nucleus of 

 two whorls and six subsequent whorls; suture distinct, not ap- 

 pressed; the anal fasciole sloping forward flatly to the shoulder of 

 the whorl with only arcuate incremental lines for sculpture; axial 

 sculpture of (on the last whorl about 20) obliquely protractive short 

 ribs, strongest at the shoulder and on the last whorl stopping 

 abruptly near the periphery; spiral sculpture hardly perceptible, on 

 the base are a few distant obsolete threads and faint microscopic 

 striae; these vary in strength in different specimens; anal sulcus 

 rounded, wide and shallow; outer lip thin, sharp, arcuately pro- 

 duced; aperture narrowly ovate, inner lip erased; pillar and canal 

 short, the latter wide and hardly differentiated. Height of shell, 

 9 ; of last whorl, 5.5 ; diameter, 4 mm. Cat. No. 210724, U.S.N.M. 



