E. t. parvâ, albidâ, nitente, subdiaphanâ, planatâ; anfr. nucl. ii. et dimidio, lævis, diaphanis; norm. uno et dimidio, rotundatis; postice carinâ valde extante, et fossâ concavâ contiguâ suturam tenus, supra spiram vix planatam ascendente; in medio basis rotundatæ carinâ alterâ plus minusve extante; inter eas, circa peripheriam, lirulis radiantibus minimis, haud expressis, sub lente vix conspicuis; regione umbilicari parum concavo; aperturâ circulari; labro à carinis angulato; columellâ, valde callosâ, porrecta; callositate pyriformi regionem umbilicarem circumambiente.
Long. 0·03, long, spir. 0. (?) lat. 0·45, div. 180°.
Hab. San Diego, Cooper, shell-washings.
Typical among the Vitrinelloid Ethaliæ described in Maz. Cat., Nos. 310, 318. Remarkable for the small number of turns in the mature shell as compared with the nucleus.
Ethalia var. invallata, Cpr.
E. t. “E. supravallatæ,” aliter exacte simili; sed vallo spirali omnino carente; basi angulatâ, haud carinatâ.
Hab. San Diego, shell-washings, Cooper.
These shells would certainly have been regarded as distinct, but for one specimen which began smoothly, yet after a fracture suddenly commenced a (not prominent) keel: an instructive lesson on variations in sculpture.