252 GINGLYMACONCHA. PHOLADIDZ. 
imdurated slate-rocks: at Hastings, in the indurated state, I 
found a variety with the anterior margin of the shell much re- 
flexed and fringed with spines in great abundance, and at first 
believed that I had found a new species; but having some 
doubts whether it might be distinct or not, I hired a man and 
a boy with wedges and sledge-hammers, with which we broke 
the rocks and found several hundreds of specimens, by which I 
was enabled to prove, by comparing them, that it is a mere 
variety. 
The flesh of this species is greatly esteemed as delicious 
food by the inhabitants of the shores of the Mediterranean, who 
pay a high price for it. I am informed by my friend Dr. Good- 
all that it is also eaten in Wales. I can myself vouch for the 
truth of what I have here stated; for during a short residence 
at Hastings I have eat them stewed, in company with some 
friends of mine, and we all agreed that the Mediterraneans had 
an excellent taste. 
Genus 2. ZIRPH#A. 
Shells subovate, with a rounded notch below anteriorly, 
gaping behind ; each valve has an impressed oblique line which 
forms an internal rib; the reflected portion hollow and simple 
beneath ; one very short, situated behind the umbones, and not 
covering the anterior adductor muscle. 
ZIRPH ZA CRISPATA. 
Shell nearly as far as its middle, especially anteriorly, muri- 
cated, above subcancellated, with waved concentric striz below; 
the epidermis very pale fuscous. 
The animal whitish ; its tracheal tubes punctulated with red. 
Pholas crispata, Linn. Syst. Nat, xii. 516. no. 2125. 
Mya crispata, Linn. Faun. Suec. 2125. 
Solen crispus, Gmel. Syst. Nat. 3216. no. 6; Penn. Brit. 
Zool. w.°77. t. xi. f. 12; Pult. Cat. Dors. 27. 42a 
4; Chem. Conch. vii. t. cu. f. 872 ad 174; Brug. Encyel. 
Meéthod. 169. t. elxiv. f. 5, 6, 7; Donov. Brit. Shells, t. lvii. ; 
Mont. Test. Brit. 23; M. §& R. Trans. Linn. Soc. vii. 33 ; 
Flem. Edinb. Encycl. vii. 100; Dill. Desc. Cat. 40; Turt. 
