TRANSACTIONS OF WAGNER 

 780 

 ' TERTIARY FAUNA OF FLORIDA 



Shell large, irregular, taking the form of the object to which it adheres, 

 the upper valve convex, with rude, irregular radial tlireads or unequal riblets, 

 close-set and frequently broken up so as to appear vermicular; interior 

 smooth, with two muscular impressions rather feebly impressed, the site of 

 the resilium deeply impressed and extending behind the cardinal margin; 

 attached valve concave, irregular, the foramen small and elongate, probably 

 eventually closed, the chondrophore projecting partly over it in our specimens ; 

 space between the valves very small. Alt. 44, lat. 58, diam. 7 mm. 



This species is one of the few characteristic fossils which are preserved 

 at Rock Bluff, and has not occurred at Oak Grove or Alum Bluff in the same 

 horizon, which may be explained by the fact that the bed at Rock Bluff is an 

 old oyster reef, in which only Ostrea, Turritclla, the present species, and frag- 

 ments of Peclen and Balanits are preserved. The matrix is ill adapted to 

 conserve fossils in their perfection, and the specimens of Pododesmus are very 

 irregular and mostly shattered by internal movements of the marl. 



Section Monia Gray. 



Pododesmus (Monia) macroschisma Deshayes. 



Anomia macroscliisiiia Desh., Rev. Zool. Soc. Cuvierienne, p. 359, 1839 ; Mag. ZooL, 



1841, pi. 34; Middendorf, Beitr. Mai. Ross., iii., p. 6, 1849; Phil., Abbild. beschr. 



Conch., p. 132, pi. I, fig. 4, 1850. 

 Placiinaiiomia tnacroscJiisma Gray, P. Z. S., 1849, p. 121; Cat. Anom. Brit. Mus., p. 



12, 1850 ; Cpr., Rep. Brit. As., 1863, p. 646. 

 Planmanomia ccpio Gray, P. Z. S., 1849, p. 121 ; Cat. Anom. Brit. Mus., p. 11, 1850; 



Reeve, Conch. Icon., pi. 3, fig. 12, 1859. 

 Placiincniomia alope Gray, op. cit., p. 122, 1849 ; Reeve, Conch. Icon., pi. 3, fig. 11. 



Upper Miocene of Sooke, Vancouver Island, C. F. Newcombe; Plio- 

 cene of San Diego, California, Hemphill; Pleistocene of California, Oregon, 

 and Alaska, Dall ; recent from North Japan to Kamchatka, the Aleutian 

 district and southeastern Alaskan coasts south to Lower California in shallow 

 water. 



This species is abundant in the Pleistocene and occurs in the Californian 

 Phocene of the San Diego well. It is a very large, solid, and characteristic 

 species. Carpenter referred a fossil of the Carrizo Creek Miocene, Anomia 

 siibcosiata, to this species, but the subcostata is a true Anouna. It is possible 

 that Plaatnanomia inornata Gabb, referred by him to the Cretaceous and by 

 Conrad to the Tejon Eocene, may belong in this section, and it even greatly 

 resembles this species externally (cf Pal. Cal., p. 217, pi. 32, figs. 288, 288 a. 



