Cymatium (Monoplex) pileare (Linnaeus, 1758) Western Atlantic

Beu, A.G., 2010. Neogene tonnoidean gastropods of tropical and South America: Contributions of the Dominican Republic and Panama Paleontology Projects and uplift of the Central American Isthmus. Bulletins of American Paleontology 377-378: 1-549 incl. 79 pls. August.

Off Pompano Beach, Broward County, Florida (38 mm.)

    Interestingly, the protoconch of this morph (see images below) was mistaken for an adult shell and named  Litiopa effusa by C. B. Adams  (1850: 71) [unfigured and type lost fide Clench and Turner, 1950: 276]. The protoconchs of Litiopa spp. have a reticulated sculpture quite unlike that of this species. This is the first but not the only case of mistaken identity of a ranellid protoconch. The protoconch of Cymatium parthenopeum (von Salis, 1793) was named Dissentoma prima by Pilsbry (1945: 59-60; fig. 1) and that of Cymatium aquatile  (Reeve, 1844) Rissoa cruzensis Nowell-Usticke (1969: 10, pl. 2, fig. 258).

Adams, C.B., 1850. Contributions to Conchology H. Bailliere, New York. iv + 258. issued in 12 parts. <http://www.biodiversitylibrary.org/bibliography/13932#/summary>

Clench, W.J. and R.D. Turner, 1950. The western Atlantic marine mollusks described by C. B. Adams. Occ. Pap. Moll. 1(15): 233-403 incl. pls. 29-49. 26 June. <http://www.biodiversitylibrary.org/item/32851#page/251/mode/1up>

Nowell-Usticke, G.W., 1969. A Supplementary Listing of New Shells, to be Added to the Check List of the Marine Shells of St. Croix. Published privately, St. Croix. 32 pp., 6 pls. Feb.

Pilsbry, H.A., 1945. New Floridian marine mollusks. The Nautilus 59: 59-60, pl. 6. October.

<http://www.biodiversitylibrary.org/item/34885#page/79/mode/1up>

(60-100 mm.)