MALACOZOA. TROPIOPODA. LAMELLIBRANCIIIATA. 215 



and a depression in the other. Named after Mr. 

 O'Kelly, of Dubhn. Turton. 



1. kellia suborbiculdris. — Shell roundish-elliptical, 

 isomeral, convex, vei^- thin, fragile, semitransparent, 

 oljsoletely concentrically striate. Suborhiciddris, nearly 

 spherical. 



2. Kellia rubra. — Shell ovato-rotundate, anisomeral, 

 convex, moderately thick, obsoletely concentrically stri- 

 ato-sulcate. Ruber, red. 



Genus 2. Leptox. — Shell suborbicular, equivalve, 

 compressed, slightly open at the ends, concentrically 

 striate ; umbones small ; hinge with a small tooth and 

 two depressions in one valve, a medial depression and 

 two lamelliform lateral teeth in the other. AeTrroy, thin, 

 small. Turton. 



1 . Lepton nitidum. — Shell ovato-orbicular, subtrigonal, 

 nearly equilateral, semitransparent, glossy, faintly striated 

 concentrically. Nitidus, shining. 



Genus 3. Cryptodon. — Shell suborbicular, nearly equi- 

 valve, inequilateral, concentrically striate ; umbones 

 small ; hinge with a small tooth in each valve, and 

 thickened margins ; two longitudinal plicae along the 

 posterior margin. KpuTrroy, concealed ; ohovs, tooth. 

 Turton. 



1. Cryptodon Jlexudsus. — Shell suborbicular, very 

 convex, thin, brittle, transparent, with a deep sinus 

 bounded by two rounded plicae on the hind part of each 

 valve. Flexuusus, bent or winding. 



Genus 4. Tellina. — Shell roundish, subtrigonal, or 

 oblong, inequivalve, inequilateral, concentrically striated, 

 much compressed, umbones small, hinge with two small 

 teeth in each valve, or two in one, and a single tooth in 

 the other ; ligament external and prominent. Name 

 obscure. Linnaeus. 



1. Tellina sol'idula. — Shell orbiculato-trigonal, convex, 

 obsoletely rugoso-striate, varv^ing in colour from white to 

 pink. SoUdulv.s, small and firm. 



2. Tellina crdssa. — Shell ovato-orbicular, compressed, 



