PISA TETRAODON. 
OF Acer Ne 
P. test lateribus utrinque 6-spinosis: spinis duabus minoribus ; quatuor majoribus. 
Cancer tetraodon. Penn. Brit. Zool. iv. 7. tab. viii. fig. 15. 
Maja tetraodon. Bose, Hist. Nat. des Crust. 1. 254. 
Leach, Edinb. Encycl. vii. 395. 
Blastus tetraodon. —————--————— vii. 43. 
Pisa tetraodon. Leach Trans. Linn. Soc. xi. 328. 
Encycl. Britan. Suppl. 1. 415. 
Fig. 1. Pisatetraodon mas. 2. maris abdomen. 3. ra:mina. 4, ramin® abdomen, 5. 
Antenna. 6. Pedipalpus externus. 
This animal inhabits deep water on the coasts of the Isle of Wight, Brighton, and Teign- 
mouth. It is often thrown on the shore after storms. 
The arms of the young males are scarcely thicker than those of the adult female. 
