Aet, 11 NEW AMERICAN MAEINE MOLLUSKS BARTSCH 27 



measures, length, 7.4 mm.; diameter, 2.9 mm. Cat. No. 363781, 

 U.S.N.M., contains a younger specimen collected by H. N. Lowe at 

 Laguna, California. We give a figure of this also. 



CERITHIOPSIS (CERITHIOPSroELLA) SANTACRUZANA, new species 

 Plate 5, fig. 3 



Shell stout, very broadly conic, pale brown. Early nuclear whorls 

 decollated, the last one and one-half marked by very slender, dis- 

 tantly spaced, decidely protractively slanting axial riblets, while the 

 broad spaces between them are marked by slender raised threads 

 which are placed at right angles to the axial riblets. Postnuclear 

 whorls moderately rounded, marked by strong, retractively slanting 

 axial ribs. Of these, 16 occur upon the first to fourth, 18 upon the 

 fifth, 20 upon the sixth and seventh, and 22 upon the penultimate 

 turn. The spaces which separate the axial ribs are about as wide as 

 the ribs. In addition to the axial sculpture, the whorls are marked 

 between summit and suture by three strong spiral cords, of which the 

 first, which is at the sunmiit, is a little weaker than the other two on 

 all the turns but the last. The junction of the axial ribs and spiral 

 cords form strong tubercles which are truncated posteriorly and 

 slope more gently anteriorly. The spaces inclosed between them are 

 roundish pits. Suture moderately impressed. Periphery of the last 

 whorl marked by a rather strong cord. The space separating this 

 from the cords of the spire is crossed by the continuation of the axial 

 ribs, which extend to the cord but do not cross it, nor do they tuber- 

 culate it. Base short, moderately rounded, marked by a spiral cord 

 which is a little less strong than the one at the periphery from which 

 it is separated by a channel a little narrower than that separating the 

 peripheral cord from the first supraperipheral. Aperture subquad- 

 rate, decidedly channeled anteriorly; posterior angle obtuse; outer 

 lip rendered wavy by the external sculpture; inner lip sigmoid. 



The type, Cat. No. 363785 U.S.N.M., comes from Santa Cruz, 

 California. It has 10 whorls and measures, length, 6.9 mm. ; diame- 

 ter, 2 mm. 



ALABA CATALINENSIS Bartsch 



Plate 2, fig. 5 



Alaba catalinensis Baetsch, Journ. Wash. Acad. Sci., vol. 10, 1920, No. 20, 

 p. 572. 



Shell elongate-conic, milk white, early whorls well rounded, the 

 succeeding turns a little less so. All whorls polished, appressed at 

 the summit, and marked by fine retractively slanting lines of growth. 

 Beginning with the second turn, varicial thickenings make their ap- 

 pearance; these are very feeble on the early whorls, but increase 



