THIA. 65 



them (' Cornish Fauna/ p. 71). 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. 



Thta polita, Leach. Polished Crab. (Plate IY. fig. 

 4.) — Carapace very smooth, and margined with long hairs. 

 Eyes very small. \Vhen alive the carapace is of a rosy 

 hue. 



Dr. Scouler obtained a specimen at Eoundstone, 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. 



