TRANSACTIONS OF WAGNER 

 1318 



TERTIARY FAUNA OF FLORIDA 



Cytherea Lamarck in the genus Venus and there was a Cytherea Mortoni of 

 Conrad from the Eocene. V. obtusa Conrad (a preoccupied name) is a patho- 

 logically stunted and thickened shell of the species under discussion, and Mer- 

 cenaria cuneata Conrad is an exceptionally short V. Mortoni, forming the ex- 

 treme in brevity which contrasts with V. tetrica, which is the most elongated 

 mutation. Mercenaria carolinensis Conrad is an average, moderate-sized shell 

 with the form of V. permagna and some thickening of the lamellae medially. 

 This also occurs in the recent state. 



The following names have been given to the quite young shell, not over two 

 inches in length: Venus calcarea Philippi, V. tenuilamellata Sowerby, and V. 

 fulgnrans Tryon, all of the suborbicular type. 



Genus MAROIA H. and A. Adams. 

 Marcia H. and A. Adams, Gen. Rec. Moll., ii., p. 423, Feb., 1857 ; not of Chenu, 1862, or 



Tryon, 1884. 

 <^Katelysia Romer, Krit. Unters., p. 17, May, 1857; Venus exalbida Chemnitz, V. scala- 



rina Lamarck. 

 Murcia (pars) Romer, Krit. Unters., p. 16, 1857; not Murcia Koch, Arachnida, 1835. 

 ^Katelysia Tryon, Syst. Conch., iii., p. 177, 1884 (F. scalarina). 

 '^Catelysia Fischer, Man. de Conchyl., pp. 1084, 1086, 1887. 



Marcia Fischer, Man. de Conchyl., p. 1086, 1887 ( V. exalbida) ; not of Chenu, 1862. 

 ^Hemitapes Romer, Mai. Blatt., xi., p. 83, 1864, type Venus rimularis Lamarck (as V. 



virginea L.) ; Mon. Venus, ii., p. 97, 1872 ; =z Pullastra (sp.) Morch, Cat Yoldi, ii., p. 



21, 1853; not Hemitapes Stoliczka, Cret. Pel. India, p. 144, 1871, or Tryon, Syst. 



Conch., iii., p. 182, 1884, or Fischer, Man. de Conchyl., p. 1086, 1887 {Venus pinguis 



Dillwyn). 

 ^Chamclea Chenu, Man. de Conchyl., ii., p. 81, 1862 {Venus aphrodinoides Lamarck) ; 



not of Morch, 1853, or Romer, 185;. 

 -^Textivenus Cossmann, Cat. Illustr., i., p. 97, 1886 {Venus texta Lamarck); Fischer, 



Man. de Conchyl., p. 1087, 1887. 

 y Mercenaria Cossmann, Cat. Illustr., i., p. 94, 1886; not of Schumacher, 1817. 

 ^Venerella Cossmann, Cat. Illustr., i., p. 93, 1886, Venus hermonvillensis Deshayes; 



Fischer, Man. de Conchyl., p. 1087, 1887. 

 Chione and Tapes (sp.) Deshayes, Cat. Conch. Brit. Mus., i., p. 147-50, etc., 1853. 



The synonym}- of this group is so mixed that hardly any rearrange- 

 ment can be suggested which is not open to some criticism. After much cogi- 

 tation the following schema appears to be the least objectionable of any that 

 has appeared to be feasible at all. 



Marcia was proposed, as a subgenus of Chione Miihlfeld, by H. and A. 



