117 



NUCULA Palms. 



TAB. CCCCLXXV— /g. 1. 



Spec. Char. Transversely elongated^ very con- 

 \ex, shining ; extremities rounded^ equal ; 

 beaks nearly central. 



Almost cylindrical with rounded ends ; the lines of 

 growth are sharply but irregularly marked, otherways 

 the surface is smooth, shining and regularly convex. 

 The beaks are partly broken away, but a compensation 

 is made for their loss by the exposure of the hinge teeth. 

 This is probably a very rare shell ; it is from Mr. Mar- 

 tin's collection of Derbyshire fossils, although not 

 figured by him. 



NUCULA variabilis. 

 TAB. CCCCLXXV.— /g. 2. 



Spec. Char. Transversely oval^ elongated, some- 

 times oblique, rather depressed, smooth ; 

 beaks near one end. 



1 HE form of this shell is very variable ; it is sometimes 

 very oblique ; but the beaks are constantly near the pos- 

 terior extremity, which is generally rather less rounded 

 than the other ; the greatest depth of the valves is near 

 the beaks ; the lunette is neither impressed nor con- 

 spicuous. 



An elegant and very distinct Nucula, although some- 

 what related to N. similis (M. C. 192), which is very 

 different in form. 



From the Ancliff collection. The small figures are 

 of the natural size. 



