Shell similar to G. Gabbii, but white, with the spiral sculpture sharp instead of rounded and the intervals wider and more irregular; the shell is more slender in proportion to its length, and the last whorl smaller in proportion to the spire ; the ribs (about 16) are sharp and the spirals minutely nodulous where they cross the crests of the ribs ; the latter cross over the periphery and grow gradually smaller to the canal, never bifurcating; the varix is much thinner, and the indentation behind it much less marked ; there is no gathering up of nodulations at the suture, and the anal fasciole is smoother or even quite free from spiral threads. The largest specimen had not completed its lirations in the aperture and on the inner lip, but they seemed fewer, coarser, and more irregular than in G. Gabbii. Max height of shell, 17.5 mm ; of last whorl, 10.5 mm; max. width of shell, 6.0 mm. There are seven normal and three nuclear whorls.

Gulf of Mexico. Between the Mississippi delta and Cedar Keys, Florida. Off Culebra Island. Off Havana (Cuba). Bed of the Gulf Stream, Pourtales.