CRUSTACEA. 677 



Pinnoteres LATE. Shell orbiculate. Peduncles of eyes short. 

 Chelas short, thick. 



Sp. Pinnoteres pisum LATE, (and Finn, mytilorum ejusd.), Cancer pisum L., 

 FABR., BASTER NatuurTc. Uitsp. n. Tab. iv. figs, i, 2, Cuv. KAni., ed. ill., 

 Crust. PL 19, fig. i, BELL Brit. Crust, p. 121; in mussels. Another 

 species, Pinnoteres veterum Bosc, lives in Pinna and was supposed by the 

 ancients to warn this bivalve against impending danger (see CICERO de 

 Finib. mat. et bon. in. Cap. 29, the mid.). 



The females are larger, have a broader shell and especially a much 

 broader tail than the males. 



Sub-genera : Xanthasia, Pinnixa WHITE, Ann. of nat. Hist. xvni. 

 pp. 176, 177. 



Grapsus LAM. Shell depressed, subquadrate, with frons broad 

 and lateral margins almost straight. Eyes placed at the lateral 

 angles of shell upon short thick peduncles. Middle antennae hori- 

 zontal, concealed under the reflected frons. First pair of feet short. 



Sp. Grapsus pictus LATR., Cancer grapsus L., DESMAR. Crust. PI. 16, fig. i, 

 Cuv. R. Ani., ed. ill., Crust. PI. 22 ; Grapsus variegatus LATR., Cane, 

 varieg. FABR., GUERIN Iconogr., Crust. PL 6, fig. i. 



Add genera : Sesarma EDW. (Pachysoma, DE HAAN), Varuna 

 EDW. (Trichopus DE HAAN), Pseudograpsus EDW. and some others, 

 which must be here omitted. 



Gecarcinus LEACH. Shell cordate, anteriorly broader, turgid, 

 posteriorly truncated. Peduncles of eyes short, received in rounded 

 furrows. 



Spi Gecarcinus ruricola, Cancer ruricola L., DESMAR. Crust. PL 12, fig. 2, 

 &c. ; from S. America. 



This genus contains the so-called land-crabs, that live in woods. Some 

 betake themselves at a certain time of the year to the sea to lay their eggs, 

 and undertake the journey in large troops, as travellers relate, in a straight 

 line, from which they cannot be turned by any opposition. 



Plagusia LATE. Frons excised on both sides for middle an- 

 i ienna3 denuded above, porrect. Shell broad, narrowed anteriorly, 

 thirst pair of feet short. 



Sp. Plagusia clavimana, DESMAR. Crust. PL 14, fig. 2, &c. 



Ocypode FABR. Shell quadrate or trapeziform, anteriorly 



liroader. Middle antennae short, with two very small seta? ; lateral 



intennae small. Eyes placed on long peduncles. Chela in males 



jften very large on one side, far surpassing the chela of the other 



ide. 



