Posted: Aug 23 2012
Octomarginula ostheimerae (Abbott, 1958)
CLICK HERE for more information and photos of Montfortia emarginata (Blainville, 1825).
8/26/12 Harry Lee:
Nice presentation - and cutting edge!
The type locality of Emarginula ostheimerae is a beach on Grand Cayman (Abbott, 1958: 18). Technically the Cayman Islands are in the West Indies but not in the Antilles (Greater or Lesser). Thus the type locality may be added to your reported range for this species, which you apparently took from Abbott (1974).
It appears that Montfortia emarginata is an older species, occurring in the Pliocene of Shell Creek, FL (Dall, 1903: pl. 55, fig. 3; pl. 60, fig. 17 [plates and plate explanations only]; as Subemarginula retiporosa) as well as throughout the Caribbean Basin and much of the Gulf of Mexico in the Recent. Perhaps McLean thought this fossil taxon was ancestral to, rather than synonymous with, M. e. (They certainly look similar, but I lack the McLean work.)
Abbott, R. T. 1958. The marine mollusks of Grand Cayman Island, British West Indies. Monographs of the Academy of Natural Sciences of Philadelphia 11: [viii] + 138 pp., 5 pls. 31 Dec.
Dall, W. H. 1903. Contributions to the Tertiary fauna of Florida with especial reference to the silex beds of Tampa and the Pliocene beds of the Caloosahatchie River. Part VI. Concluding the work. Transactions of the Wagner Free Institute of Science of Philadelphia 3: i-xiv + 1219-1654, pls. 48-60. October.
8/27/12 Harry, again:
Thanks to Marlo I now have a copy of Jim McLean's monograph on the Hemitominae.
McLean does not mention the Pliocene Subemarginula retiporosa Dall, 1903, but he does put the genus Montfortia in the Lower Pliocene of Jamaica, consistent with my observation above.
Also speaking of Jamaica, McLean cites that Greater Antilles as a locality for Hemimarginula dentigera - an addition to the range cited by Marlo.