MANUAL OF THE MOLLUSCA. 



Family YIII. — Hippunrrn)^.* 



Genus : — Hippurites. 



Sub-genus, D' Orhignya, Woodward, 1862. 



Type, H. bi-oculatus, Lamk. ; no " ligamental inflection " of 

 the outer shell. 



Fossil, 4 species. Middle Chalk. Europe. 



Barrettia, Woodward, 1862, dedicated to Mr. Lucas Barrett, 

 late Director of the Geological Sui'vey of the West Indies. 



Tyjje, B. monilifera, Woodward. " Hippurite Limestone." 

 Jamaica. No "ligamental inflection" as in D'Orbignya, but 

 presents the further peculiarity of an indefinite number of pal- 

 lial duplicatures extending all round the margin of the lower 

 valve. 



Family XI. — LirciNn)^.+ 

 LORIPES, Poll, 1791 (Jefi'reys) (see p. 456). 



Etymology, lorum, a strap ; and pes^ a foot. 



Example, Tellina lactea, Linne. 



Animal with the margin of the mantle notched; incurrent 

 tube long. 



Shell almost equilateral, cancellated, or sculptured by 

 flexuous striae; lunule short; cartilage quite internal; teeth, 

 one cardinal in the right, and two in the left valve ; laterals 

 remote, and sometimes indistinct. 



Distribution, species. Atlantic, Mediterranean, West Indies. 



Fossil, species. Eocene . Erance. 



AxiiOJS, J. Sowerby, 1821 (see p. 431). 



/S2/720W?/?72S, Thysaira, &c.. Leach; Bequania, Leach; Crypto- 

 don, Turton ; Ptychina, Philippi ; Thiatyra, G. Sowby. ; Clau- 

 eina, Jefi'reys. 



Example, Tellina flexuosa, Montagu. 



Animal with the mantle margin thickened, open, not pro- 

 longed into tubes ; foot long, sub-cylindrical, and very slender. 



Shell globular, posterior side furrowed or angulated, umbones 

 much recurved ; lunule short or indistinct ; ligament usually 

 and to a certain extent external, j)laced in a groove on the hinge 

 line, and outside the hinge-plate ; teeth altogether wanting. 



In A. flexuosus, the hinge-plate is indented in the right valve 

 immediately below the beaks, and slightly reflected in the left, 

 * See p. 440. t See p. 455. 



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