In the two left-hand columns are ten examples of the species referred to in Bahamian Seashells as Gibberula sp. B. Distinguishing features include remarkable consistency in the shape and location of the two main color patches, the composition of the color patches - (groupings of black dots in a paler central area) - and the divergent white bars at the posterior end of the foot. In the right-hand column are five examples of the species referred to in Bahamian Seashells as Gibberula sp. D. Distinguishing features include consistency in the shape and location of the two main color patches, the composition of those patches - (orange spots against a black background) - and the parallel white bars at the posterior end of the foot. Differences in the profile of the shells might also be noted.

A comment at the following link suggests that these are all examples of a single species:
                      www.malacolog.org/search.php?nameid=11433

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Megadenus holothuricola Rosén, 1910

This is perhaps the rarest known shallow-water species in the Bahamas. Megadenus holothuricola was described from the Bahamas in 1910 from five specimens that were found living in the respiratory tree of the sea cucumber Holothuria mexicana. Warén (1984) reported that the type material is lost. I know of no published records of this eulimid having been rediscovered since its original description, two photos from which are reproduced (in part) above. These photos of the species in situ show a small white conical shell with what appears to be a cylindrical protoconch of two narrow whorls. Subsequent whorls enlarge rapidly. If anybody has any additional information on this species, I’d be glad to add it here.

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• Megadenus holothuricola
• Figure 470E in Bahamian Seashells
• Two species of Gibberula



 

A fresh look at figure 470E
in Bahamian Seashells

Figure 470E in Bahamian Seashells depicted a very beachworn sinistral shell that was identified as a species of Gibberula.

The figure is reproduced below (left) and reversed (right) to show what the shell would look like if dextral.

The shell is now considered to be a very poor example of an immature, sinistral  Prunum apicinum.

Click here for some comments on the
Compendium of Brazilian Sea Shells
by Eliézer Rios (2009)