SHELLS COLLECTED IN JAPAN. 293 



CYTHEREA FORMOSA. 



Plate 1, figs. 1, 2, 3, 4. Var. figs. 5, 6. 

 Cytherea testa C. meretrici simili, seel mag is obliqua et elongata ; latere postico elongatiusculo ; 

 colore pallido, fasciis griseis suffuso, prope umbones castaneo biracliato. 

 Habitat, Lew Chew. 

 Cytherea Formosa, (Sowb., jr.) 



This shell is more oblique and more elongated than C. meretrix, which it otherwise greatly 

 resembles. The hinder part is colored with grey, and there are also two broad chestnut-colored 

 rays, commencing at the umbones, and interrupted near the centre. 



cytherea morphina. 



Plate 2, figs. 3, 4, 5 ; fig. 10, var. 



Cytherea testa, C. meretrici simili, sed lateribus suffusis, lunula magis inflata, marginibus 

 crassioribus ; colore pallide fulvo, griseo radiatim fasciato. 



Shell thicker, more spreading at the sides, with a rather straighter and thicker margin and 

 more turned lunule than Cytherea meretrix ; no posterior purple band ; the color pale reddish 

 brown, with greyish rays. 



Habitat, Canton river, China, var. Lew Chew. 



Cytherea morphina, (Lam.) 



CYTHEREA petechialis. 

 Plate 2, figs. 6, 1, 8, 9. 



Cytherea testa C. meretrix simillima, sed multum altiore ; margine rotundissimo ; latere 

 postico rotundatim angulato ; colore subgriseo fusco-rufescente angulatim lineato. 



Shell rounder and higher than C. meretrix, the ventral margin very much rounded ; the 

 lateral angle rather more distinct ; colored in much the same way as Cytherea meretrix, but 

 without the purple posterior area. 



Habitat, Canton river, China, and also at Lew Chew. 



Cytherea petechialis, (Lam.) 



Found in great abundance and of very large size. 



DIPSAS PLICATUS. 

 Plate 3, fig. 1, 2. 



I have figured this shell on account of its size, and also to show the way in which these shells 

 are ornamented by the natives. 



A piece of lead of any fanciful shape is inserted under the mantel of the animal while yet 

 alive, after which the shell is returned to the water ; in a short time the leaden ornaments are 

 found covered with pearly matter as seen in the figure. 



The specimen in my own collection is marked as coming from Shanghai. 



pecten yessoensis. 

 Plate 4, figs. 1, 2. 



Plate 3, figs. 3, 4. 



Testa orbiculari, insequivalvi, valva sinistra piano convexa, ascpilaterali, costis triginta convexo 



planis, sublente tenuissime et criberrime concentrica striata, valva dextra convexiore costis 



