Posted: Apr 30 2017

Olivella dealbata (Reeve, 1850)

On April 29, 2017 I made an inquiry on Conch-L for specimens

of Olivella dealbata. Harry Lee replied, "I do not think Olivella

dealbata occurs in FL." Harry included a link to a photo on

Jaxshells (inserted adjacent) illustrating Olivella monilifera.

I replied:

"OK Harry, help us out here. Your link illustrates O. monilifera

(Reeve, 1850) with O. dealbata as a synonym. Both are by

Reeve of the same date (1850). WoRMS presents just the

opposite, as did Malacolog."

Harry responded with the following observations:

"• Sally Kaicher (cards 5014 and 5015, showing the holotypes of Oliva dealbata and O. monilifera respectively) convinced me (+ jaxshells) of the conspecificity of the two taxa, and that has been the response of pretty much every worker.

• Kaicher (and I .. "back in the day") considered Porphyria dealbata Röding, 1798 a senior secondary homonym of the first Reeve taxon, since we considered the two to be congeneric (Olivella spp.). This homonymy made the Reeve's O. dealbata permanently invalid, the obvious synonymy a moot issue, and Olivella monilifera (Reeve, 1850) the valid name for the biotaxon.

• However, the preceding treatment now proves untenable since the Röding taxon is now placed in Olivina rather than Olivella. Although Kaicher and I (+ jaxshells) treated Olivina as a subgenus, what I call "hierarchy crawl" has exalted Olivina to a full genus of late and exempts the two taxa from secondary homonymy.

• The date of publication of both nomina is noted at the bottom of the pages: October ... and November, 1850, respectively (see Reeve's descriptions, below). This volume of Conchologia Iconica took two years for completion, being issued in many parts from Nov., 1849 to March, 1851. As a consequence of this methodology, the title page bears the date "1851."

• Since O. dealbata Reeve is freed from homonymy, it becomes the a senior synonym by chronological priority, which principle jibes with the treatment by WoRMS and Malacolog 4.1.1. Today my (+ jaxshells) and Kaicher's nomenclatorial conclusions are incorrect. Although a rather subjective matter, the consensus supports this reversal.

• The FL record for O. dealbata appears to be based on Olsson (1956: 185; pl. 15, figs. 6, 6a, 6b), who identifies a dumpy shell with the Reeve taxon, a clearly erroneous diagnosis.

• Short version: Olivella dealbata (Reeve, Oct. 1850) + O. monilifera (Reeve, Nov. 1850); O. monilifera (Reeve, Nov. 1850) = Olivella dealbata (Reeve, Oct. 1850). Florida occurrence disputed.

Olsson, A.A., 1956. Studies in the genus Olivella. Proceedings of the Academy of Natural Sciences of Philadelphia 108: 155-225, pls. 8-16. 3 Oct. < >"