156 CRUSTACEA. DECAPODA. 



the middle of the internal side ; anterior legs equal, those of 

 the male three times the length of the body ; of the female 

 longer than the body. 



33. aspera, Leach. Anterior legs and thighs tuberculated ; shell 

 with eight tubercles on the back more elevated than the others, 

 margined with hairs ; sides with four lamellae. Inhabits British 

 seas Pen. Brit. Zool. iv. pi. 10, fig. 3. 



Gen. 29. PISA, Leach. Cancer, Herbst. 

 External antennae with clubbed hairs, the first joint larger than 

 the second ; forceps long ; shell villose, triangular, tubercu- 

 lous, and dentated anteriorly and laterally ; orbits behind with 

 two, and below with one, fissure ; claws of the last five pairs 

 of feet dentated internally. 



P. Gibbsii, Leach. (C. biaculeatus, Mont.) Rostrum descending ; 

 shell with a spine behind the eyes on each side ; arms and thighs 

 simple. Inhabits coasts of Britain Lin. Trans, xi.pl. 1, fig. ]. 



P. tetraodon, Leach. (Cancer, Penn.) Shell with six spines on each 



side, two small, the rest larger. Inhabits coasts of Britain 



Pen. Brit. Zool. iv. pi. 8, fig. 2. 



Gen. 30. MAIA, Lam. Cancer, Herbst 

 Exterior antennas with the first two joints thickest, and of near- 

 ly equal length ; shell convex, ovate, subtriangular, very spi- 

 nous ; eyes not thicker than their peduncle ; third joint of 

 the exterior feet-jaws longer than broad, with a deep internal 

 notch ; claws with naked sharp points ; forceps scarcely thick- 

 er than the other claws. 



The animals of this genus are generally known under the name of Spider-Crabs. 

 They live on rocky or muddy coasts, and conceal themselves among fuci. 



M. squinado, Lam. Shell covered with hairy tubercles, and spinous ; 

 two long diverging spines in front, and the sides with five spines ; 

 hands smooth, cylindrical. 4 inches long. Inhabits European 

 seas. B Herbst, pi. 14, fig. 84, 85. 



Gen. 31. STENOPUS, Lat. Palcemon, Oliv. 

 Middle or upper antennae terminated by two setaceous filaments, 

 almost equal, and longer than the body ; three first pairs of feet 

 with a didactyle hand ; the third pair very long ; body soft, 

 hispid ; shell terminated before by a short spinous rostrum. 



S. hispidus, Lat. Shell covered with small slightly bent spines ; 

 a semicircular impression behind the rostrum ; abdomen and la- 

 minae of the tail rough with spines, and ciliated ; the third pair 

 of feet large, angular, and hispid, with two elongated claws. 2 

 inches long. Inhabits Southern ocean. Desm. Crust. 227- 



Gen. 32. HYAS, Leach. Mala, Bosc. 

 Shell elongate, subtriangular, subtuberculated, the sides behind 



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