COfiCRYUA—DITHYRA. xxiii- 



10. SPflENIA 



1. Binghami, cuneata, dente concavo obliquo infiexo. 



wedge-shaped, with the concave tooth oblique 

 and inflected. 



2. Swainsoni, ovata, dente concavo horizontali-protenso. 



oval, with the concave tooth projecting horizon- 

 tally inwards. 



3. decussata, decussatim striata. 



with decussate striae. 



11. CORBULA. 



1. Nucleus, Corhnla. 



12. Pandora. 

 1. margaritacea. Pandora. 



13. Panop.ea. 

 1. Glycymeris, Panopeea. 



14. Anatina, 



* CocJdearihus ohJiquis. 



with the spoon-shaped teeth oblique. 



1. convexa, oblonga, cochlearihus integerrimis. 



oblong, with the teeth very entire. 



2. piibescens, ohlonga, cochlearihus emarginatis . 



oblong, with a notch on the teeth. 



3. tninrata, cuneata, umbo7iibus subterminalibus. 



wedge-shaped, with the beaks nearly terminal. 



