Shell small (to 14.4 mm in total length), broadly fusiform, glossy, truncated anteriorly; body whorl approximately 60% of total length. Whorls convex, sutures impressed, slightly undulant over ribs of the previous whorl. Protoconch paucispiral with 1,75-2 smooth, glossy round whorls, first whorl not immersed. Axial sculpture of broad slightly opisthocline ribs that extend from suture-to-suture on spire whorls but fade rapidly on shell base; 7-8 ribs on the penultimate and 7 on last whorl to varix. Ribs with rounded crests, widest mid-whorl, slightly recurved on shoulder. Spiral sculpture beginning as faint spiral grooves on shell base then developing into ridges that are strongest on anterior fasciole. Sulcus absent; shoulder with slightly recurved ribs. Varix an expanded rib, cup handle shaped, positioned behind the anal sinus. Outer tip thin, narrow, its edge a smooth arc from the anterior edge of the anal sinus, to the anterior canal; stromboid notch small, shallow, close to the anterior end and indicated by just a ruffle in the lip's edge. An axial fold present between varix and edge of outer lip. Anal sinus a shallow U-shaped notch on shoulder, sides divergent. Inner lip moderately wide, emarginated and erect anteriorly, with a parietal callus joining the outer lip at the suture. Anterior canal short, open, and unnotched; anterior fasciole not swollen. Color white to pale golden brown.

Cerodrillia yucatecana has all the shell characters diagnostic of Cerodrillia, including suture-to-suture axial ribs, a cup-handle-like varix located behind the anal sinus, and a polished shell surface with faint spirals confined to the shell base. Variability. The average total length of three specimens is 11.0 mm (9.0—4.4 mm), and their average W/L ratio is 0.407. Identification. Cerodrillia yucatecana is close to C porcellana, new species, to C sanibelensis, new species, and to C ambigua, new species. From C porcellana it differs in possessing ribs with round, not ridged crests, a longer more tapering anterior end, and a different color—white to pale golden brown, not porcellaneous white. From C sanibelensis it differs in possessing more evenly rounded whorl profiles, not "sagging" whorls where whorl peripheries are below their pidpoint. From C ambigua it differs in possessing lower, broader and fewer ribs (7-8 versus 9-11 on the penultimate whorl) that are slightly opisthocline. The ribs on C ambigua are slightly more prominent and straighten

Gulf of Mexico (NW of Yucatan and N Quintana Roo). Reported depths are 91-128 m.