200 SYSTEMATIC PALEONTOLOGY 



American authors for the most part not regarding the American speci- 

 mens referable to the European species M. balthica. Dall who has care- 

 fully studied the species, however, regards them as the same. 



This species has been found in the Pleistocene along the coasts of the 

 North Atlantic and Pacific oceans extending in America as far south as 

 South Carolina. In the Eecent it is found in all arctic and boreal seas 

 extending as far south as Georgia in America and to the Mediterranean 

 in Europe. 



Width, 33 mm. ; height, 25 mm. 



Occurrence. — Talbot Fobmation - . Wailes Bluff near Cornfield Har- 

 bor, St. Mary's County. 



Collections. — Maryland Geological Survey, Johns Hopkins University, 

 and U. S. National Museum. 



Family PSAMMOBIIDAE. 



Genus TAGELUS Gray. 



Tagelus gibbus (Spengler). 



Plate LVII. 



Solen gibbus Spengler, 1794, Skrift. Nat. Selsk, vol. iii, pt. 2, p. 104. 

 Solecurtus caribceus Conrad, 1831, Amer. Mar. Conch., p. 22, pi. iv, fig. 3. 

 Siliquaria caribcea Holmes, 1858, Post-Pi. Fos. S. C, p. 54, pi. viii, fig. 14. 

 Tagelus gibbus Dall, 1900, Trans. Wagner Free Inst. Sci., vol. iii, pt. v, 

 p. 983. 



Description. — " Solen gibbus, testa lineari, valvula antice et postice 

 gibbos-lineari obliqua." Spengler, 1794. 



This species was figured by Lister in Hist. Conch. Tab. 421, Fig. 265. 



Numerous nearly perfect specimens of this interesting species occur 

 in the Maryland Pleistocene. It makes its first appearance in the Miocene 

 of Virginia and continues its existence through the Pliocene of South 

 Carolina and Florida. In the Pleistocene it is found in Massachusetts 

 (New Bedford), Maryland, and South Carolina and Dall also reports it 

 from Florida and the Gulf coast. In the Eecent it ranges from Cape Cod 

 southward to Florida and to Brazil, and it also occurs on the west coast of 

 Africa as well as on the British coast. 



Width, 83 mm.; height, 32.5 mm. 



