404 MOLLUSCA. 
TELLINA CONCENTRICA (Gould). 
T. transversa, ovato-trigona, tenuis, convexiuscula, albida, haud nitida, 
ubique concentrice lamellosa, et radiatim inter lamellas subtilissime 
striata ; lamellis equalibus, acutis, confertis, reflexts ; umbonibus viz 
post-medianis: pars antica semi-elliptica ; margine dorsal viz declivi : 
pars postica sub-triangularis; margine dorsali valde dechvt, sub- 
arcuato, valde excavato, ad apicem truncato ; flexura conspicua, haud 
lamellosa : intus alba. 
Tellina concentrica, GouLp; Proceed. Boston Soc. Nat. Hist., 111. 253. 
June 1850. Expedition Shells, 80. 
Suet thin, transversely-ovate triangular, subequilateral, white 
outside and in, ornamented with numerous, equally-spaced, thin, con- 
centric lamelle, about equally developed throughout; and having the 
interspaces marked with very delicate, radiating strie; beaks a little 
past the middle, acute, compressed ; anterior dorsal slope slightly de- 
clining, rectilinear; extremity broadly rounded; anterior umbonal 
slope tumid; posterior dorsal slope nearly rectilinear, rapidly declin- 
ing, tip truncated; flexure well-marked; ligament cavity long and 
deep; shell broadest at anterior third. Lateral teeth remote, the poste- 
rior one conspicuous, the anterior one less so. 
Length an inch and five-eighths; height an inch and one-eighth ; 
breadth half an inch. 
Inhabits the Feejee Islands. 
Like 7' capsoides, Lam., but less triangular, the anterior portion 
more tumid, and its dorsal slope arcuate; the flexure is more decided ; 
the concentric lamine decided and uniform throughout; the radiating 
strie are very delicate, and found equally before and behind, not cross- 
ing the concentric lamine. It is much like T. préstis, Lam., except 
in form, and its anterior dorsal margin, which is represented as ser- 
rated. : 
Figures 519, 519 a, lateral and dorsal views of the shell; 519 b, the 
hinge. 
