CONCHIFERA. 4838 
Example, S. livida, Pl. XXII., Fig. 1. 8. diphos, Fig. 2. 
8S. orbiculata, Fig. 3. 
Shell oval, compressed, rounded in front, attenuated and 
slightly gaping behind ; hinge-teeth 3, small; siphonal inflec- 
tion very deep, connected with the pallial line; ligament ex- 
ternal, on very prominent fulcra. 
Animal, mantle open, fringed; siphons very long, branchial 
largest orifices fringed; foot large, broadly tongue-shaped, 
compressed ; palpilong pointed; gills recumbent, inner laminz 
free, dorsal border wide. 
Distribution, 20 species. West Indies, Red Sea, India, Mada- 
gascar, Japan; Australia, Tasmania, Peru. 
Fossil, 30 species. Hocene—. United States, Europe. 
SEMELE, Schumacher, 1817. 
Etymology, Semele, in Greek myth. the mother of Bacchus. 
Synonym, Amphidesma, Lamarck, 1818.* 
Type, 8. reticulata, Pl. XXI., Fig. 11. 
Shell rounded, sub-equilateral, beaks turned forwards; pos- 
terior side slightly folded; hinge-teeth 2.2, laterals elongated, 
distinct in the right valve; external ligament short, cartilage 
internal, long, oblique; pallal sinus deep, rounded. 
Distribution, 60 species. West Indies, Brazil, India, China, 
Australia, Peru. 
Fossil, 30 species. Hocene—. United States, Europe. 
Sub-genera. Cumingia, G. Sowerby. C. lamellosa, Pl. XXI., 
Fig. 12. Shell slightly attenuated and gaping behind, lamel- 
lated concentrically ; cartilage-process prominent; pallial sinus 
very wide. Distribution, 10 species. In sponges, sand, and 
the fissures of rocks, — 7 fathoms. West Indies, India, Aus- 
tralia, West America. Fossil, Miocene—. Wilmington, North 
Carolina. 
Syndosmya, Recluz. Synonyms, Abra, Leach MS. LErycina 
(part), Lamarck, 1805.¢ Type, 8. Alba, Pl. XXI., Fig. 18. 
Shell small, oval, white and shining; posterior side shortest; 
umbones directed backwards ; cartilage-process oblique; hinge- 
teeth minute or obsolete, laterals distinct; pallial sinus wide 
and shallow. Animal with the mantle open, fringed; siphons 
* The name Amphi-desma, as employed by Lamarck, included species of Semele, 
Loripes, Syndosmya, Mesodesmu, Thracia, Lyonsia, and Kellia ; in addition to which 
it has since been applied to some Oolitic Myacites. 
+ The nams A#rycina was originally applied by Lamarck to a number of minute 
fossil shells, including sp. of Syndosmya, Venus, Lucina, Tellina, Astarte, and Kellia. 
In 1808 Fabricius employed it for a well-known group of insects. 
¥ 2 
