Described in French (click French flag)

Description. Shell small (to 13.6 mm in total length), glossy, fusiform, up to about 10¼ slightly convex whorls, the last approximately 53% of total length, flattened dorso-ventrally and rapidly tapering, “pinched” when viewed ventrally, to a narrow anterior canal. Spire whorls appear compressed—proportionally shorter than wide. Shell sculpture of ribs with deep intercostal spiral grooves. Protoconch of approximately 1½–1¾ smooth translucent whorls, the first not immersed in the second. Axial sculpture of narrow opisthocline ribs that run from suture-to-suture on spire whorls, evanesce at anterior fasciole of last whorl and are absent on dorsum of last; intercostal spaces greater than rib width. Ribs recurved in sulcus, sigmoid on ventrum of last whorl, number 12–14 on penultimate, 7–9 on last whorl to varix. Spiral sculpture of evenly spaced deep grooves in intercostal spaces (rib crests are smooth) more closely spaced in sulcus. Grooves present across the dorsum of the last whorl. Grooves give the appearance of closely packed spiral cords, number about 8 on penultimate and 12 on shell base, and 7 on anterior fasciole. Sulcus with recurved ribs that are lower than the ribs on the whorl face, ribs overridden by spiral grooves giving sulcus the appearance of having 3–4 spiral cords. Varix hump-like, positioned ½-turn from edge of outer lip; its position causing the body whorl to appear compressed dorso-laterally. Outer lip thin, but strengthened by up to 4 axial folds clustered on about the last ¼-turn, the one closest to the edge the strongest; edge forms a low almost flat arch from anal sinus to stromboid notch where it is bent slightly inward. Stromboid notch deep. The dorsum of the last whorl thin, translucent, and except for their presence in the sulcus, ribs obsolete. Anal sinusdeep, U-shaped, entrance constricted by parietal lobe and projection of outer lip, somewhat tubular and projecting laterally. Inner lip edge free, erect anteriorly, recumbent on parietal wall, and formed into a parietal lobe posteriorly, arching over the rear of the aperture. Anterior canal moderately long, open and narrow, turned slightly to the right and dorsally; deeply notched. Color pink, rib crests lighter, varix white, apex violet, and dorsum of last whorl brown.

Agladrillia rhodochroa has the distinguishing characteristics of the genus: a varix ½-turn from the edge of the outer lip, a strongly constricted anterior canal, and a smooth dorsum on last whorl. Dautzenberg described his specimens, which were from Colombia, as having a pink base, ribs a purplish rose, and the back of the last whorl a wide brown spot. The specimens depicted in Plate 2, all from Colombia, closely match his description and drawing. Variability. The average length of 9 measured specimens is 11.37 mm (9.9–13.6 mm) and average W/L ratio is 0.376. Some difference in color and form is seen between the Cartagena and Magdalena Departments’ specimens that is believed at this time to be geographic variation, not rising to the level of species. Identification. Agladrillia rhodochroa is most similar to A. aureola, new species. It differs in color, which is pink with a brown varical spot and not golden yellow with an orange brown varical spot, and in relative whorl height, which is higher in A. aureola. Also, whorls are less convex and axial ribs more oblique than in A. aureola. Agladrillia rhodochroa differs from Calliclava tobagoensis, new species, in possessing a smooth protoconch, a greater constriction of the anterior canal and a varix located ½-turn from the edge of the outer lip. The latter species has a carinate protoconch, a less-constricted anterior canal, and a varix located about ⅓-turn from the edge of the outer lip.

Type locality. Rio Hacha [Guajira Dept.] Chazalie Station 52, Colombia, at 6 m depth (locality of the lectotype). Other specimens from the type series were collected at Chazalie Stations 41, 42, 44, Santa Marta [Magdalena Dept.], Colombia, at 15, 40, and 23 m depths, respectively.
Range and habitat. Colombia (Bolivar, Magdalena & Guajira Depts.), at depths between 2 and 60 m. If the specimen illustrated by Massemin et al. is this species, then its southern range would extend to French Guiana.