Zoological Society. 63 



Hah. Baclayon, island of Bohol, Philippines (found in sandy mud 

 at the depth of seventeen fathoms) ; Cuming. 



This species is chiefly distinguished from its congeners, the Mya- 

 dor(B tincta and trigona, by its more oblong shape. 



4. Myadora ovata. Myad. testd ovatd, suhtriangulari, valvd 

 sinistrd ventricoso-concavd, dextrd levitcr convexd, concentrice 

 striatd, striis elevatis, prope marginem anticam suhobsoletis , valvce 

 dextrcB numerosis, confertis, sinistra: prominentibus, subdistantibus, 

 umbonibus depresso-incurvis. 



Conch. Iconica, Myadora, pi. 1. f. 4. 



Hah. San Nicolas, island of Zebu, Philippines (found in sandy 

 mud at the depth of six fathoms) ; Cuming. 



This species exhibits a greater disparity in the sculpture of the 

 valves than any other, the striae of the right valve being very fine and 

 close-set, whilst those of the left are almost keel- like and compara- 

 tively distant. 



5. Myadora tincta. Myad. testd trigona, antice subtruncatd, 

 usque marginem concentrice striatd, striis elevatis, prominentibus ; 

 fuscescente tinctd. 



Conch. Iconica, Myadora, pi. 1. f. 5. 



Hah. Island of Ticao, Philippines (found in coral sand at the depth 

 of six fathoms) ; Cuming. 



The Myadora tincta scarcely differs from the Myadora plana, ex- 

 cept in being of a less oblong and more triangular form. 



6. Myadora striata, Gray, MSS. British Museum; Pandora 

 striata, Deshayes. 



Conch. Iconica, Myadora, pi. 1. f. 6. «, &, andc. 

 Hah. Port Nicholson, New Zealand ; Swainson. 

 This is the grand type of the genus, and of much larger size than 

 any other species. 



7. Myadora brevis. Anatina brevis, Stutchbury, Zool. Journ. 

 vol. V. p. 99 ; Tab, Supp. xliii. f. 1 and 2. 



Conch. Iconica, Myadora, pi. 1. f. 7. 



This is a very interesting form, and the striae of the left valve are 

 peculiarly wrinkled. 



8. Myadora oblonga. Myad. testd trigono-ohlongd, antice latis- 

 sime truncatd, concentrice striatd, striis elevatis, regularibus , prope 

 marginem anticam angulatis. 



Conch. Iconica, Myadora, pi. 1. f. 8. 

 Hah. Island of Mindoro, Philippines ; Cuming. 

 The anterior side of this species is the most broadly truncated of 

 any. 



9. Myadora cuRVATA. Myad. testd curvato-ohlongd, valvd dextrd 

 convexiusculd, antice subindistincte flexuoso-costatd, concentrice 

 striatd, striis elevatis, angustis, regularibus. 



Conch. Iconica, Myadora, pi. 1. f. 9. 



Hah. Island of Corrigidor, Philippines ; Cuming. 



This species differs also in form rather than in variety of sculpture. 



