156 
striz; the line of the hinge is as long as the shell is wide, 
forming the diameter of its semicircular edge. 
From the same place and person as the last: this and 
the two former are extremely britile; they are little else 
than the earthy part of the shell remaining, coloured by 
Tron Oxide. 
PRODUCTUS aculeatus. 
TAB. LXVIII.—Ig. 4. 
Conchiliolithus (Anomites) aculeatus. Mart. 
Petrif. Derb. T. 37. F. 9 and 10, 
Spec. Cuar. Roundish, concave valve smooth; the 
other with adpressed reflected spines; gibbous ; 
front slightly indented ; hinge half the breadth 
of the shell. 
a 
Tur spines are so adpressed to the convex valve, that 
they appear as if they were forcing their way through it 
and raising its surface, with their points towards the beak 
or backwards, chiefly on the sides, about ten on each, in 
nearly regular alternate order. Length rather less than 
the breadth, which is seldom three-quarters of an inch. 
On the convex valve are several obscure concentric 
undulations. 
I had this from Mr. Martin; it is rather smaller than his 
figure, and is a cast in a light coloured Limestone with the 
shelly remains very thin. He says it is found near Bake- 
well and Buxton. The beaks, he observes, are often 
broken, giving them the appearance of being perforated. 
Mine is broken off, but I have represented it as if whole; 
the allowance is easily made. 
