CONCHOLOGY. 97 



summit sub-anterior, well marked, and curved ; exterior fawn 

 colour, interior of a silvery hue. 



P. deaurata. The golden red Patella. PI. 2, fig. 3. 

 Sub-conic, summit more anterior, with a slight forward in- 

 clination ; colour yellowish red. 



P. cochlear. The spoonlike Patella. PI. 2, fig. 4. 



Depressed, the summit hardly marked, and much more 

 narrow in front than behind ; exterior brownish, interior light 

 blue. 



P. scutellaris. The buckler Patella. PI. 2, fig. 5. 



Depressed, summit sub-anterior, radiated from the summit 

 to the margin ; brown colour, with a yellowish band parallel 

 to the margin. 



P. pectinata. The pectinated Patella. PI. 2, fig. 6. 



Oval, summit well marked and anteriorly inclined ; ribbed 

 from the summit to the margin, which is slightly convex in 

 the middle. 



P. cymhularia. The cymbular Patella. PI. 2, fig. 7. 

 Oval, thin, pearly, with a festooned margin ; summit nearly 

 marginal ; colour white, shaded with very light brown. 



FAMILY III. 



Calyptracea. Seven genera. 



The genera that constitute this family were separated by 

 Lamarck from the Patella of Linn^us. 



1. Parmaphora. The Duck's-bill Limpet. Three species. 



The characteristic distinctions of this shell were first 

 pointed out by De Blainville. 



Shell elongated, very depressed ; the summit greatly post- 

 medial, and evidently inclined behind ; aperture as large as 

 the shell ; the lateral edges straight and parallel, the poste- 

 rior rounded, the anterior sharp and notched in the middle ; 



N 



