306 MANUAL OF THE MOLLUSCA. 



Sub -genus, Grateloupia, Desra, G. irregularis, PL XX. fig. 11. 



Shell sub-equilateral, rounded in front, attenuated behind ; hinge with 1 

 anterior tooth, 3 cardinal teeth and several small posterior teeth ; pallial 

 sinus deep, oblique. Fossil, 4 sp. Eocene Miocene. U. States, France. 



ARTEMIS, Poli. 



Etym. Artemis, in Greek myth. Diana. 



Type, A. exoleta, PL XX. fig. 12. (Sijn. Dosinia, Scopoli.) 



Shell orbicular, compressed, concentrically striated, pale ; ligament sunk ; 

 lunule deep ; hinge like Cytherea ; margins even ; pallial sinus deep, angular, 

 ascending. 



Animal with a large hatchet-shaped foot, projecting from the ventral 

 margin of the shell ; mantle-margins slightly plaited ; ^iphons united to their 

 ends ; orifices simple ; palpi narrow. 



Distr. 85 sp. Boreal Tropical seas; low-water 80 fms. 



Fossil, 8 sp. Miocene . U. States, Europe, S. India. 



Sub-genera. Cyclina, Desh. V. Sinensis, Chemn. Orbicular, vcntricose, 

 margins crenulated, no lunule, sinus deep and angular. Distr. 10 sp. 

 Senegal, India, China, Japan. W. America. Fossil, 1 sp. Miocene, Bor- 

 deaux. 



dementia (papyracea) Gray. Thin, oval, white; ligament semi-internal; 

 posterior teeth bifid, sinus deep and angular. Animal with long, united 

 siphons, and a large crescentic foot, similar to Artemis. Distr. 3 sp. 

 Australia, Philippines. 



LUCINOPSIS, Forbes. 



Syn. Dosinia, Gray, 1847 (not Scop.) Mysia, Gray, 1851 (not Leach). 

 Cyclina, Gray, 1853 (not Desh.) 



Type, Venus undata, Pennant, PL XX. fig. 13. (Lucina, and opsis, like.) 



Shell lenticular, rather thin ; right valve with 2 laminar, diverging teeth, 

 left with 3 teeth, the central bifid: muscular impressions oval, polished; 

 pallial sinus very deep, ascending. 



Animal with mantle-margins plain; pedal opening contracted; foot 

 pointed, basal ; siphons longer than the shell, separate, divergent, with fringcc 

 orifices. (Clark.) 



Distr. 1 sp. Norway, Brit. Fossil, 3 sp. Miocene. Brit. Belgium. 



TAPES, Miihlfeldt. 



Syn. Paphia, Bolten, 1798. Pullastra, G. Shy. 

 Example, T. pullastra, PL XX. fig. 14. (Tapes, tapestry.) 

 Shell oblong, umbones anterior, margins smooth ; teeth 3 in each valve 

 more or less bifid ; pallial sinus deep, rounded. 



Animal spinning a byssus; foot thick, lanceolate, grooved; mantle plai 



