JJ(» BIVALVE SHELLS. 



PisL-M, Merjerle, Gray, P. Z. S. 1847, n. 556. Shell ovate- 

 wcilgeshapcd, ineqvnlateial, truuc-ated behind ; siphous of 

 auiinal short, united to the end. P. amnicitm." — Gray, Ann. 

 cV Ma(^. N. H. ser. 2. xi. 3H. 



A. Denies cardinales 3 • 3, anterior in valva dextra et posterior 

 in valva sinistra minores. Testa solida. Corbiculina, 

 Gray. 



Genus 1. CORBICULA. 



Animal ignotum. 



Testa ovato-trigona, subsequilateralis, cordiformis, in utraque 

 valva cai-do tridentato, dentibus divergentibus, dentes lateralcs 

 duo scquales, compressi, teuui, transversim striati. Nymphae 

 breves basi nigosae ; impressiones musculares minores rotundatsc 

 vel semilunares ; impressio palUi simplex. 



TelHna. MM. Verm. Hist. ii. 205. 



Venus, Chemn. (1/82) Conch, vi. 319. 



Cvclas (spec), Britg. (1792) Encycl. MeU. pi. 301, 302. 



Lamk. (1799) Essai d'une Class., Mem. de la Soc. d'Hist. 

 Nat. de Paris, i. 

 C>Tena (ex parte), Lamk. (1818) An. s. Vert. v. 551. 

 Corbicula, Megerle (1811), Entwurf. p. 56. 



Gray (1847), Proc.Zool. Soc.p. 184 ; (1853) Ann. c^ Mag. 

 Nat. Hist. xi. 38. 

 Cyanoeyclas, Blainv. (1818), Diet. Sc. Nat. xii. 280. 



" Mantle (of Corbicula consobrina), lobes free on the lower 

 edge and in front, united behind ; edge simple, with a series of 

 short conical beards just within the margin ; si])hons two, veiy 

 short, separate, contractile ; apertures fringed with short crowded 

 conical beards; foot compressed, subquadrate, rather produced 

 in front ; l)ody swollen ; abductor muscles large, anterior oblong, 

 the hinder round, subtrigoual. 



" Labial tentacles 2 pair, large, broad, trigonal, equal ; gills 

 oblong, inner pair large, the outer about half the depth of the 

 inner." — Gray, MSS. 



a. Species Europce, 

 1. Corbicula Panormitana. 



C. testa trigoua, suba'quilaterali, antice rotundata, postice angu- 

 lata, transverse striata, disco depresso ; apieibus acutis, incur- 



