149 



1. brevis, Stutch. 



2. crassa, id. 



3. curvata, Reeve. 



4. oblonga, id. 



Species. 



5. ovata, Reeve. 8. striata, Desk. 



6. Pandorseformis, Stutch. 9. tincta, Reeve. 



7. plana, Reeve. 10. trigona, id. 



Myodora striata. 

 angular form. 



Figure. 

 PI. 41. Fig. 226. Shell, showing its flattened tri- 



Genus 4. PANDORA, Bruguiere. 



Animal; oval, compressed ; the mantle closed except for the pas- 

 sage of a narrow tongue-shaped foot; siphons very short, 

 united nearly to their orifices, lohich are divergent and fringed. 

 (Forbes.) 



Shell ; inequivalve, inequilateral, white, pearly in the interior, one 

 valve fiat, the other more or less convex ; hinge composed of a 

 diverging ledge-like tooth in one or both valves, with correspond- 

 ing pits ; ligament lodged by the side of the tooth. 



To genus Pandora is referred a series of small semitransparent pearl- 

 white shells, light in substance, of which the left valve is convex and the 

 right valve flat, and the hind part of the shell, from which issue the ani- 

 mal's siphons, is mostly flexuously drawn out, compressed, and beaked. 

 The hinge is composed of two ledge-like teeth in one or both valves, di- 

 verging as in Placuna, and the ligament is lodged in a cicatrix or super- 

 ficial pit alongside. Considering the variable depth of habitat and wide 

 range of geographical distribution of the Pa?idora, the species are very 

 few in number. They inhabit muddy soil, at depths varying from five to 

 a hundred fathoms, on our own shores and those of North America and 

 Spitzbergen, the Mediterranean, and parts of India, New Zealand, and 

 Panama. 



1. arenata, Sow. 



2. Ceylanica, id. 



3. cistula, Gould. 



Species. 



4. claviculata, Carp. 



5. cornuta, C. B. Adams. 



6. depressa, Sow. 



7. discors, Soto. 



8. flexuosa, Donov. 



9. glacialis, Leach. 



