CRUSTACEA. 679 



Compare on this genus TH. BELL Observations on the genus Carcinus &c. 

 Transact, of the Zool. Soc. I. 4, 1835, PP- 335 34 2 PL 43 47- 



Add genera : Gonoplax LEACH, Pilumnus LEACH, Xa/ntho LEACH, 

 and some others proposed by DE HAAN. 



Portunus DALD., FABR. Shell depressed, posteriorly truncated, 

 mostly transverse, broader than long. Two last feet natatory, with 

 tarsus depressed, flat. 



A. Two posterior feet alone natatory. 



Carcinus LEACH. Tarsus of fifth pair of feet narrow, lanceolate. 

 Petioles of eyes short. 



Sp. Carcinus mosnas, Cancer mcenas L., BASTER NatuurTc. Uitsp. n. Tab. 11., 

 BELL Brit. Crust, p. 76 ; the shore-crab ; forward between the eyes the 

 shell has three points, and on each side at the margin five triangular teeth. 

 This crab is very common on our shores. 



Portunus LEACH. Tarsus of fifth pair of feet dilated, oral. 



Petioles of eyes short. 



Add sub-genus Thalamita LATE, and genus Lupa LEACH in part. 

 Sp. Portunus puber LEAOH, Cancer puber L., DESMAR. Crust. PI. 5, fig. i, 

 BELL. Brit. Crust, p. go. 



Podophthalmus LAM. Tarsus of fifth pair of feet dilated, oval. 

 Peduncles of eyes cylindrical, very long, produced as far as the 

 angles of shell, received in a canal in the margin of shell. Shell 

 short, transverse, depressed, on both sides at the anterior angle bi- 

 spinose. 



Sp. Podophthalmus splnosus LAM., LATR., Portunus vigil FABE. Suppl. 

 Entom. syst. p. 363, DESMAE. Crust. PI. 6, fig. i, GUEEIN Iconogr., Crust. 

 PI. i, fig. 3 ; from the Indian Ocean. 



B. Four pairs of feet natatory) with tarsus foliaceous. 

 Platonychus LATR. (and Polybius LEACH, and species of genus 



Lupa LEACH, sub- genus Neptunus DE HAAN). 



Sp. Polybius Henslowii LEACH, DESMAR. Crust. PI, 7, fig. i, BELL Brit. 

 Crust, p. 1 1 6. 



Lupa pelagica LEACH, Cancer pelagicus L., EUMPH. Amb. Rariteitk. 

 Tab. vn. fig. E, DESMAE. Crust. PI. 6, fig. 2, DE HAAN Crust. Jap. PI. 

 IX. X. ; this beautiful species with smooth shell running into a sharp point 

 on each side between the second and third pairs of feet, is found in the Bed 

 Sea, the whole Indian Ocean, and especially on the coast of Japan, where 

 it is very common, and a favourite food of the natives. 



