Acc. to Aguayo & Jaume : Size 1.14 x 0.78 mm, error for 1.14 x 0.68 mm in accordance with figure. Cuba. The species is very variable regarding the ratio length/width from 100:55 to 100: 75. A wide specimen was figured by Carnes from Yucatan, 1.06 x 0.76 mm as A. cf. vallei. Collected at the north coast; at Aruba from material dredged from the harbour.

Amphithalamus vallei Aguayo and Jaume, 1947 del Valle's Tiny Shell
Distribution: Florida, Texas; Bahamas; Lesser Antilles. Size: 1 mm .
Description: Color amber to chestnut brown on fresh specimens; shape elongate pupoid; sculpture smooth except on protoconch, which is made up of 1 ¥2 pit¬ted nuclear whorls; teleoconch with 2 rounded smooth whorls, periphery of body whorl with a slight carination; last part of body whorl slightly detached from aperture, producing a shelflike channel bordering the columella; aperture subcircular to ovate; umbilicus chinklike; operculum translucent.
Habitat: Found associated with algae. Specimen in the photograph from FGB. Specimens collected at FGB at depths from 22 to 51 m (70 to 168 ft). Previously recorded depth range 0 to 15 m (50 ft).
Remarks: Easily confused with Assiminea succinea. See Abbott (1974); Redfern (2001).