Lamarck’s Genera of Shells. 299 
a few species the ligament appears a little, on the outside. 
They are all sea shells, and generally become very thick by 
age. 
Type. Crassatella kingicola *. 
Shell ovate, orbicular, subgibbous, whitish, inclining to yel- 
low, obsoletely radiated; transverse striz delicate; nates 
plicate. New Holland. 18 Species. PI. v. Fig. 33. 
4, Erycina. 
Shell transverse, subinequilateral, equivalve, seldom gaping. 
Two unequal, diverging, cardinal teeth, with an interposed 
_ pit. Two oblong, compressed, short, entering, lateral teeth. 
Ligament internal, fixed in the pits. 
One of the cardinal teeth joining the base of the lateral 
tooth on the same side, has been sometimes mistaken for a bifid 
tooth, and its external lobe has been supposed to exhibit the 
element of the plicated tooth of the mactrz; but the corre- 
sponding hollow on the opposite valve shows that idea to be 
erroneous. 
One species. Erycina cardioides +. 
Shell ovate orbicular, small, decussately striated ; transverse 
striz remote: the longitudinal very close. New Holland. 
Pl. v. Fig. 34. 
5. Ungulina ¥. 
Shell longitudinal, or transverse, rounded on the upper part, 
nearly equilateral ; valves close; beaks eroded. One short, sub- 
bifid, cardinal tooth on each valve, with an oblong marginal pit 
beside it, divided in two by a contraction in the middle. Liga- 
ment internal, inserted in the pits. 
The unguline are furrowed externally, and tinged red on the 
inside. 
* An inhabitant of King Island, New Holland. Our figure is copied by 
Mr. G.B. Sowerby’s permission, from his elegant and accurate work, now 
in course of publication, entitled ‘ The Genera of Recent and Fossil Shells.’ 
We have not been able to procure a specimen of the species. 
+ Cardium-shaped Erycina, We have given a second figure, E. compla- 
nata of Sowerby. 
t Ungula, a nail, or hoof. 
