As I have seen no complete list of the very numerous fossil species of this genus, it appears allowable, rather than risk a synonym, to name this graceful shell after its discoverer.
Genus? Mesalia, Gray.
? Mesalia tenuisculpta, Cpr. n. s. State Collection, No. 666 a.
? M. t. tenui, regulariter turritâ, fusco-cinereâ; anfr. nucl. lævibus, normalibus, apice acuto; norm. viii. rotundatis, suturis impressis; lirulis spiralibus; haud extantibus, plus minusve distantibus, irregularibus cinctâ quarum anfr. primis duæ anticæ majores; lirulis circa basim rotundatam obtusis, subregularibus; rugulis incrementi irregularibus, interdum decussantibus; aperturâ subrotundatâ, peritremati haud continuâ; labro acuto, postice flexuoso; labio tenui.
Long. 0·28, long. spir. 0·18, lat. 0·10, div. 15°.
Hab. S. Diego; 4-6 fms., 15, alive. Cooper.
Intermediate in character between Mesalia and Fenella.