THIA. 
65 
them (‘ Cornish Fauna/' p. 74). In Devon it is named the 
Old Man’s Face Crab. 
Gen. 21. THIA, Leach . 
Carapace heart-shaped, much contracted behind, smooth 
and arched only from side to side; front wide, lamellar, and 
considerably projecting ; front legs short and compressed ; 
the other legs still shorter, and terminating in a straight 
and very sharp joint. Abdomen nearly of similar form in 
both sexes. 
Thia polita, Leach. Polished Crab. (Plate IY. fig. 
4.) — Carapace very smooth, and margined with long hairs. 
Eyes very small. When alive the carapace is of a rosy 
hue. 
Dr. Scouler obtained a specimen at Boundstone, Conne- 
mara, which he sent to the British Museum. Dr. Melville 
sent three specimens to Mr. Bell from Galway ; they were 
found buried in the sand. Their smooth, slightly arched 
carapace and whole form are well adapted for this habit. 
It seems to be a common species in the Mediterranean. 
F 
