55 



28. P. Solaris, (pi. xii. f. 7, 8, 22.) Born. Mus. Cees. t. 

 6. f. 4. 



T. rotundata, sub-sequivalvi, sub-eequilaterali, complanata ; 

 auriculis parvis, sub-sequalibus, lsevibus ; costis octodecim, 

 lsevibus, rotundatis, eequalibus, interstitiis latis, transverse 

 sub-striatis ; valvee dextrae costis latioribus, plus minusve 

 striatis, interstitiis sub-nullis ; colore pallide rubro, lineis 

 spadiceis et maculis albis rubrisque fasciatim maculato, 

 variat albo, rubro fasciatim irregulariter maculato. Long. 2. 

 15. ; lat. 0. 50. ; alt. 2. 5. ; poll. 



Orbicular, nearly equivalve, equilateral, ratber flat, auricles 

 small, nearly equal, smooth, ribs 18, smooth, rounded; in one 

 valve the ribs are broader than the interstices ; in the other, 

 the reverse, the interstices, which are very narrow in the lower 

 valve, are slightly striated. The colour is pale red, variegated 

 with irregular bands and transverse lines of red and white. 



Macassar and China. 



29. P. obliterates, (pi. xvi. f. 126.) Linn. Syst. Nat. 

 p. 1146. 



T. sub-ovali, kevi, compressa, interne striata, ad marginem 

 dentata, utrinque hiante ; auriculis eequalibus, obtusis ; colore 

 fulvo, marginibus purpurascentibus, fasciis rubris radiatim et 

 concentrice picto. Long. 1. 80.; lat. 0. 40.; alt. 1. 90.; poll. 



The internal ribs, more numerous in this species than 

 in the following, are visible externally through the semi- 

 transparent substance of the shell. The lower valve is not 

 white, though considerably lighter than the other. China. 



30. P. Pleuronectes . (pi. xvi. f. 127, 128, 135, 136.) 

 Linn. Syst. Nat. p. 1145. 



T. rotundata, sub-ovali, lsevi, compressa, utrinque hiante ; 

 auriculis fequalibus, obtusis; interne costis duodecim, dupli- 

 catis, vel viginti quatuor singulis ; interstitiis sub-striatis ; 

 colore valvee sinistra purpureo vel fulvo, vel fusco rubescente, 

 fasciis medianis, radiatis,bi-lineatis ; valvee dextrae albo. Long. 

 3. 5.; lat. 0. 60.; alt.; 3. 15.; poll. 



Rounded, rather oval, smooth, flat, gaping on both sides ; 

 the auricles equal, blunt, with 12 pairs of lightly raised linear 

 ribs within. The ground colour of the upper valve is pale 

 greyish fawn, or dark mahogany brown, or purplish pink, 

 lighter near the umbo, and radiated with bands of darker 

 colour, corresponding to the pairs of ribs within, each band 

 defined by a sharp line on either side. China. 



31. P. Japonicus. (pi. xv. f. 109, 110.) Gmel. p. 3317. 

 No. 8. 



