46 
ZOOLOGY OF THE VOYAGE OF H.M.S. SAMARANG. 
Thorax trapezoidalis, postiee coarctatus. 
Irons prominens, lamcllaris, in medio valde incisa. Antennae internee articulo secundo elongato, 
usque ad fissuram porrecto. 
Pedes posteriores pedibus Portuno simillimi. 
Abdomen (feminee) articulis septem lateribus subparallelis. Mas adhuc latet. 
External pedipalps with the third joint broader at the base than long, and not notched 
at its anterior margin near the angle. 
Carapace trapezoidal, considerably contracted posteriorly. 
Front projecting, lamellar, deeply cleft in the middle. Inner antennae with the second 
joint elongated and reaching to the commencement of the notch. 
Legs very much as in Portunus. 
Abdomen (of female) seven-jointed, the sides nearly parallel. 
This generic group, described from a female, will be found an interesting connecting 
link between the genera Portunus, Platyonychus, and Polybius. We have named it Poly- 
bioides from its resemblance to the genus of Leach, which, as Professor Bell remarks, is of a 
more decided natatory character than any other Brachyurous form found on the British coast. 
1. LISSOCARCINUS POLYBIOIDES, Adams fy White. (Tab. XI. Pig. 5.) 
Thorace pentagonali, in fronte produeto, postice coarctato, lsevissimo, multis parvis rotundatis maculis, 
lineS distinct:! ab angulo latero-anteriore projects ; margine latero-anteriore valde dentato, dentibus prorsum 
inclinatis. 
Fronte lamellari, prominente, antice bifida, antennis lateralibus fronte occultis. 
Chelis articulo quinto bicarinato ; carina antice valde dentata. Pedibus posterioribus depressis, pari 
ultimo unguibus valde dilatatis. 
Hab. Maria Orientalia. 
Carapace five-sided, produced in front, narrowed behind, very smooth on the upper 
surface, and covered with numerous small round markings, a strong line extending from the 
latero-anterior angle across the carapace towards the middle line; latero-anterior margin 
strongly toothed, the teeth directed forwards. 
Front lamellar, projecting, bifid anteriorly, covering and concealing the lateral antennae, 
a wide space between the eyes. 
Fore-legs with the fourth joint doubly keeled, the keels strongly toothed anteriorly. 
Hind-legs flattened, the fifth pair with the penultimate joint more flattened than the 
corresponding joint of the other pairs, and with a greatly dilated flattened claw. 
Hab. Eastern Seas. 
2. LUPOCYCLUS, Adams &f White. 
Pedipalpi externi articulo secundo ad apicem tenuiore (quam in Lupd L. forceps), articulo tertio 
minore (quam in Lupd). 
