Monilispira bigemma

Scientific Classification


Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
Order: Neogastropoda
Family: Pseudomelatomidae
Genus: Monilispira
Species: Monilispira bigemma (Dall, 1890)

Information

Duplin Formation

Tamiami Formation (Pinecrest Beds)

Remarks

Synonymy: Drillia bigemma Dall, 1890: p. 35, pl. 2, fig. 6.

Type Specimen: USNM 97327 (holotype), “Caloosahatchie River, near Fort Thompson, Florida” (Merrill, 1905, p. 235).

Other Combinations: Drillia bigemma Dall, 1890. Monilispira bigemma (Dall, 1890) (Accepted combination)

Original Description: From Dall, 1890 (p. 35): “Shell small, stout,fusiform, six-whorled; nucleus rather large, at first smooth, then spirally grooved; succeeding whorls rather coarsely sculptured; spiral sculpture of rather sharp grooves, with wide interspaces, cutting the transverse sculpture; on the earlier whorls there isa stout cord next the suture, in front of which the fasciole is somewhat depressed, with three or four fine spirals on it; on the periphery is a deep groove, and next the succeeding suture the whorl is again depressed; on the base of the last whorl in front of the periphery are about six interspaces between grooves, of which the first, third and fourth are depressed below the others; all the others have their posterior edges higher than the anterior edges; beside these there are four or five flattish spirals on the canal; the transverse sculpture is exhibited chiefly in the form of nodes on the spirals. On the periphery, divided by a sharp groove, is a paired series of large, axially oblong nodes; on the basal spirals the nodes are small, squarish and twice as numerous in the same spiral distance; the presutural cord has a series of round nodules which sometimes are obsolete, but when present follow the peripheral nodes; terminal varix not prominent; notch wide and deep; callus moderate; outer lip arcuate in the middle; canal wide, short, straight. Max. lon. of shell 8.0; max. lat. 3.0 mm. This species is rather peculiarly sculptured and I do not recall any recent species resembling it.”

Online Resources

WoRMS record 1787109

References

Dall, W. D. 1890. Contributions to the Tertiary Fauna of Florida, with especial reference to the Miocene Silex-Beds of Tampa and the Pliocene beds of the Caloosahatchie River. Part I. Pulmonate, opisthobranchiate and orthodont gastropods. Transactions of the Wagner Free Institute of Science of Philadelphia, 3(1): 1-200, pls. 1-12. BHL.