146 BULLETIN 68, UXITED STATES NATIONAL MUSEUM. 



ODOSTOMIA (CHRYSALLIDA) RITTERl, new species. 

 Plate 14, figs. 8, 8a. 



Shell elongate-coric, niilk-white. Nuclear whorls at least two, 

 smooth, deeply obliquely immersed in the first of the succeeding 

 turns, above which only a portion of the last two turns project. 

 Post-nuclear whorls moderately rounded, strongl}' constricted at the 

 sutures, slopingly shouldered at the summit, ornamented by strong, 

 retractive axial ribs of which 14 occur upon the first, 16 upon the 

 second to fourth, 18 upon the fifth, and 20 upon the penultimate 

 turn. In addition to the axial ribs, the whorls are marked by spiral 

 cords between the sutures, which are a little more than half as strong 

 as the ribs and of which three occur upon the first three whorls and 

 four upon the succeeding turns; the second one below the summit 

 marking the angle of the long sloping shoulder. Junction of ribs and 

 cords strongly nodulous; the spaces inclosed between them are deep 

 squarish pits. Sutures strongly channeled. Peripheiy of the last 

 whorl marked by a broad groove that is crossed by the continuations 

 of the axial ribs which terminate at the posterior margin of the first 

 basal keel. Base of the last whorl well rounded, marked hj six 

 spiral cords which are of unequal strength, separated by grooves of 

 chfferent widths, which are crossed by fine axial threads. Aperture 

 oval, effuse anteriorly; posterior angle obtuse; outer lip rendered 

 sinuous by the cords, thin, showing the external sculpture within; 

 columella slender, strongly reflected, provided with a fold at its 

 insertion. 



The type (Cat. no. 206896, U.S.X.M.) was dredged at station 30, 

 University of California, off Catalina Island. It has seven post- 

 nuclear whorls and measures: Length 4. .5 mm., diameter 1.6 mm. 

 Four topotypes are in the collection of the University of California, 

 which has the follo\ving additional specimens: Four from station 47, 

 off San Diego; three from station 59; and two from station 83, also 

 from off San Diego. Cat. no. 206897, U.S.N.M., one dredged in 

 50 fathoms, off Catalina Island. 



Named for Prof. W. E. Ritter. 



ODOSTOMIA (CHRYSALLIDA) RINELLA, new specios. 

 Plate 15, figs. 6, 6a. 



Shell elongate-ovate, cream-colored. Nuclear whorls at least 

 two, smooth, forming a depressed helicoid spire, which is obliquely 

 three-fifths immersed in the first of the succeeding turns. Post- 

 nuclearwhorls moderately rounded, strongly contracted at thesutures, 

 somewhat shouldered at the summits, marked by strong, tubercu- 

 lated axial ribs and four spiral cords almost as strong as the ribs 

 between the sutures which renders their junction with the ribs 



