JUKES-BROWNE : SYNOPSIS OF THE TENERID^. 65 



Pelecyora, Dall, 1902. Type, Cytherea hatchetigheensis, Aldrich. 



This shell seems to be distinguished by its rugose nymphs and 

 narrow aiigular pallial sinus. It is a fossil from the Eocene of the 

 United States. 



Genus Dosiniopsis, Conrad, 1864. 



Synonym, JEora^ Conrad, 1870. 



Type, Cytherea Unticularis, llogers. 



Shell sub-orbicular or rounded oval. Lunule indistinct. Escutcheon 

 often defined and depressed. Cardinal teeth three in each valve, 

 separate, divergent, and entire, except the right posterior, whicli is 

 bitid. Left median strong, central, and triangular. Anterior lateral 

 elongate, rugose, and a simple pit for its reception in the right valve ; 

 a single posterior lateral in each valve. Nymphs finely granulated. 

 Dorsal margins not grooved. Pallial sinus rather short, ascending, 

 rounded or sub-angular. 



This genus is extinct, and is only known from fossil repi'esentatives 

 in the Cretaceous and Eocene deposits. The Cretaceous species 

 D. suhratunda and the Eocene D. orbicularis have sharply depressed 

 escutcheons, and it is from them that lleroena and Sunetta have been 

 derived. 



Genus Sunetta, Link, 1807. 



At the present day this genus is specially characteristic of the 

 Indo-Pacific region, but it extends round the Cape to the west coast 

 of Africa, as far north as Senegal. In Eocene and Miocene times 

 it lived in European seas, but no species has survived in the 

 Mediterranean area. In eastern seas it I'anges from Japan on the 

 north to the coast of South Australia. The animal is unknown. 



Synonyms: Cuneiis, Megerle, 1811 (not Da Costa); Meroe, 

 Schumacher, 1817. 



Shell oval or sub-orbicular, sub-equilateral, rather thick, smooth 

 or concentrically grooved, with obscure radial riblets. Lunule 

 impressed and circumscribed ; escutcheon narrow and deeply depressed. 

 Cardinal teeth 3-3, straight, separate, and touching dorsal border; 

 the medians fairly stout, the otht-rs narrow, and all generally entire; 

 the left posterior confluent with the nymph. Anterior laterals strong, 

 one in left and two in right valve. Right posterior and left anterior 

 marginal grooves short or obsolete. Nymphs finely denticulate. 

 Pallial sinus short, sub angular, and horizontal. Ventral and lateral 

 margins crenulated (except in Meroina). Pedal scar under hinge-plate 

 and confluent with that of the adductor. 



Sunetta, s.s. Type, Donnx scripta, Linn. 



Shell elongate-oval, compressed or inflated, either equilateral or 

 posterior side the shorter. Left posterior cardinal short, right one 

 smooth and entire. 



Smietttna, Jousseaume, 1901. Type, S. sunettina, Jouss. 



Shell sub-orbicular, compressed ; posterior side expanded and rather 

 longer than the anterior. Left posterior cardinal long and thin, the 

 right one grooved at the top. 



VOL. XI. — MARCH, 1914. 5 



