 The posterior terminations of these riblets are waved, forming an obscure notch-band, each being slightly enlarged close by the suture and also on the anterior side of the band, thus forming two rows of indistinct nodulations, of which the sutural row is more clearly defined than the other.The riblets extend from suture to suture, and near its anterior third become obsolete on the body whorl.Here eight or ten rather indistinct revolving threads exist, becoming more distinct toward the end of the siphonal canal, separated from each other by shallow grooves.