BIVALVE SHELLS. 45 



Cvtherea Birmanica, Phil. Abbild. und Beschr. Cyther. p. 42. 

 ■pi. 9. f. 8. 



Hab. Mergui, imperium Birmaiiorum, 



10. CUNEUS VAGINALIS. 



C. testa ovato-orbiculari, siibtrigona, convexiuscula, anterius 

 comjjvessa, laevi, carnea, maculis radiantibus riifis virgata; intus 

 rosea, margine crenulato ; ano lineari-lanceolato ; vulva pro- 

 funde impressa, patente. 



Cytlicrea vaginalis, Menke, Moll. Nov. Holl. p. 42. 

 Callow, Cat. p. 40. no. 114. 

 Philippi, Abbild. Conch, p. 96. pi. 4. f. 2. 



Hab. Nova HoUandia occidentalis. 



Genus 5. TRIGONA. 



Animal ignotum. 



Testa triangularis, cuneiformis, subsequilateralis, inferne acuta, 

 margines integerrimi; cardo 3-5-dentatus, alter 4-6-dentatus, 

 dente laterali antico, angusto, elongato, compresso ; impressione 

 pallii postice sinuosa ; sinus brevis, obliquus vel subhorizontalis. 



Periostraca velutinaeea argentea, spiculis tenuissimis calcareis 

 constans, siccata decidua, Gray, Ann. SfMag. N. H. iv. 1849, 

 296 ; vi. 1850, 143. 

 Pectunculus triquetrus, Lister (1685), Conch, pi. 251. 

 Venus (spec.). Born (1780), Test. Mus. p. 65. 



(spec), Chemnitz (1782), Conch, t. vi. p. 328. 

 (spec.), Schroter (1783), Einl. t. iii. p. 159, 

 (spec), Dilhvyn (1817), Cat. t. i. p. '172. 

 Cytherea, Lamarck (1818), An. s. Vert. t. v. p. 559. 



Ferussac, Blainville, Deshayes, Sowerby, Sfc. 

 Trigonella, Conrad (1837), Amer. Phil. Soc. ser. 2. t. 5 (nonDa 

 Costa, nee Llhwyd). 



Hinds, Voy. iSulph. 1844, Zool. p. 65. 

 Trigona, Megerle (1811), Mag. fur die neust. Entdeck. p. 55. 

 Schumacher (1817), Essai d'une Nouvelle Classif. p. 153. 

 Gray (1838), Cat. of Cyth. Analyst, t. viii. p. 304; (1842), 

 Syn. Brit. Mus. p. 74; (1847), Proc. Zool. Soc. p. 183. 



