APPENDIX 
289 
Aperture oval; posterior angle obtuse; outer lip thin, showing the external 
sculpture within by transmitted light; inner lip slightly curved, appressed 
to the succeeding whorl for two-thirds of its length, the anterior third only 
being free; parietal wall covered with a thick callus. 
Type in United States National Museum, No. 361626. Type locality, 
Cayucos, California. It has five postnuclear whorls and measures, altitude, 
2.9 mm.; diameter, 1.8 mm. 
Odostomia catalinensis Bartsch, 1927 
Proceedings of the United States National Museum, 70: 17; PI. 3, fig. 4. 
Shell minute, bluish white, semitranslucent. Nuclear whorls deeply 
obliquely immersed in the first postnuclear turn, above which the tilted 
edge of the last turn only projects. Postnuclear whorls moderately rounded, 
marked by four strong spiral cords which are much wider than the spaces 
that separate them. Of these the first is at the summit. The axial sculpture 
is decidedly reduced on the first turn, becoming stronger on the second, 
while on the third there are 18 axial ribs which equal the spiral cords in 
strength. The junction of the axial ribs and spiral cords here form strong 
tubercles on the anterior three spiral cords, while the fourth is only slightly 
tuberculated. On the last whorl the axial ribs are very irregular and en¬ 
feebled. Here the axial sculpture consists chiefly of lines of growth, which 
are particularly conspicuous in the grooves between the spiral cords, where 
they appear as slender riblets. Particularly is this true in the groove at the 
periphery. Periphery well-rounded. Base moderately long, well-rounded, 
marked by seven spiral cords which grow successively narrower from the 
periphery toward the base, the last one at the base being a little wider than 
those immediately preceding it. Aperture oval, somewhat effuse anteriorly; 
posterior angle obtuse; outer lip thin, showing the external markings within 
by transmitted light; columella slightly oblique, strongly reflected and ap¬ 
pressed to the base, leaving only a very small chink at the umbilical area, 
and provided with a strong oblique fold at its insertion; parietal wall 
covered with a moderately thick callus. 
Type in United States National Museum, No. 347989. Type locality, 
on Abalone at Catalina Island, California. It has four and one-half post¬ 
nuclear whorls and measures, length, 3.1 mm.; diameter, 1.6 mm. 
Subgenus Evalea (see p. 182) 
Odostomia bachia Bartsch, 1927 
Proceedings of the United States National Museum , 70: 17; PI. 2, fig. 7. 
Shell very regularly elongate-ovate, bluish white. Nuclear whorls deeply 
[ 587 ] 
