17 



54 Area Solida p. 155 



55 



56 

 51 

 58 

 59 



60 



- Auriculata* 



- Trapezina p. 153 



- Transversa p. 161 

 \Divaricata p. 155 



- Pacifica p. 155 



■ Emarginata (very old) 



p. 161 



PLATE XIX. 



1 Area Alternata p. 156 



2 Lithodomus p. 156 



3 Labiosa p. 150 



4 Concinna p. 160 



5 Obesa p, 160 



6 Nux p. 160 



7 Labiata p. 160 



8 Glacialis p. 156. 



9 

 10 

 11 

 12 

 13 

 14 

 15 

 16 



17 



Formosa p. 160 



Grandis p. 160 



Cardiiformis p. 161 



Multicostata p. 161 



Tetragona p. 152 



Truncata p. 156 



Chalcanthum app. 



Decussata app. (Sul- 

 cata? p. 153) 

 Velata p. 156 



1 8 Pectunculus Spadiceus app. 



19 



20 



21 



164 



22 

 23 



24 



166 



Siculus p. 162 

 Violascensp. 163 

 Intermedius p. 



Ovatus p. 164 

 Tessellatus p. 



Tenuicostatus 



app. 



* This figure is copied from that given in Delessert's delinea- 

 tions of the unfigured specimens described by Lamarck. The ori- 

 ginal diagnosis is as follows : — 



" Cordate, ventricose, with many crenulated ribs ; umbones 

 oblique ; emarginated anteriorly. 1 § . Indian Ocean. Allied to 

 Rhombea, but smaller, with the beaks more aipiproximated.'''' The 

 figure in Delessert's magnificent folio, exhibits about thirty very 

 closely arranged ribs, and the posterior end of the ligamental area 

 destitute of any ligament. I have never met with any specimen 

 which I could satisfactorily identify with this engraving ; the shell 

 which I have described at page 157, (which is a variety of my A 

 Deshayesii, the Antiquata of Lamarck's description, but not that 

 of Linnaeus,) although sufficiently in accordance with the too brief 

 characters, evidently not being identical with the delineated spe- 

 cimen. 



