NO. 1312. SYNOPSIS OF THE VENERID.^;— BALL. 345 



1895. Dall, The Nautilus, IX, May, 1895. 



1895. Whitfield, Miocene Molluscaof New Jersey. 



1896. Locard, Annales de TUniversite de Lyon, Campatrne dn ("audaii. 

 1896. Dall, The Nautilus, X, No. 5, September. 



1896. Dall, Proceedings United States National Museum, XVIII, XIX. 



1897. Wagner, Transactions Wagner Institute of Science, V. 



1898. Verrill and Bush, Proceedings ITnited States National Museum, XX, No. 1189. 

 1898. Locard, Expeditions srientifiques du Travailleur et du Talisman, II. 



1898. Bucquoy, Dautzenberg et Dollfus, Mollusques Marins du Roussillon, II. 



1898. Posselt, Conspectus Fauna Gronlandite. 



1899. Dall, Transactions Wagner Free Institute of Science. Ill, Part 5. 



1900. Chiamente, Revista Italiana Sci. Nat., XX. 



1900. E. A. Smith, Proceedings Malacological Society of London, IV. 



1900. Sacco, I molluschi del terreni terziarii del Piemonte e della Liguria, XXVIII. 



1901. Dall and Simpson, Report on the MoUusks of Porto Rico. , 

 1901. Jousseaume, Le Naturaliste, Septembre, 1901. 



1901. Whitfield and Hovey, Bulletin American Museum of Natural History, XI. 



1902. Dall, Proceedings United States National Museum, XXIV. 

 1902. Dall, Proceedings United States National Museum, XXV. 



Family VENP^RID.E. 



The suhdivdsions adopted are characterized a.s follows: 

 SiabikiTiiiy Dosijsriiisr^ai;. 



Hinge with three left and three or four right cardinals, usually with 

 an anterior left lateral fitting into a pit in the opposite v^alve and some- 

 times a developed posterior right lateral. Siphons long and united to 

 their tips; foot large, arcuate, without a byssus or by.ssal groove; shell 

 usually orbicular and generally more or less compressed, with a dis- 

 tinct pallial sinus. 



A. Anterior and sometimes posterior laterals present^ the lunule 

 Impressed^ hut not distinctly limited. 



Genus DOSINIOPSIS Conrad, 1864. 



Type, ]). Meelxll Conrad. Eocene. 



Shell orbicular, heavy, concentrically striated, with a thick, polished 

 periostracum; lunule impressed, but not circumscribed distinctly, and 

 there is no defined escutcheon; inner margins smooth; pallial sinus 

 short, free, acutely angular, and ascending; hinge strong, with corru- 

 gated nymphs and a strong rugose left anterior lateral fitting into a 

 rugose pit in the opposite valve; right valve with a stout distinct pos- 

 terior right lateral, which fits into an excavated socket in the left 

 valve. 



This is the only genus of the family with a distinctly developed 

 posterior lateral tooth, and if it ^vere not for the number of cardinals 

 and the presence of a pallial sinus it might be referred to Cyprlna. 



