DECAPODA, 
171 
Two naturalists, travellers of the government, prematurely taken 
from the sciences, Delande and Leschenavdt-de-Latour, discovered 
two other species ; one was collected by the first in his travels to 
the south of Africa, and the other by the second in the mountains of 
Ceylon. 
The Cancer senex of Fabricius (Herbst., XL, 5), should, in my 
opinion, be referred to the same subgenus. It inhabits the East 
Indies. 
A species peculiar to America, the Thelphusa serrata, Herbst., 
X, ii, is proportionahly wider and flatter than the others, pre- 
senting certain characters which seem to indicate a particular 
division *. 
Other Quadrilatera having, like the preceding ones, the fourth 
joint of the external foot-jaws inserted in the external extremity of 
the previous joint, differ from them in the trapezoidal, transverse and 
widened form of the fore-part of the shell, as well as in their ocular 
pedicles, which, like those of the Podophthalmi, are long and slender, 
extending to the anterior angles, and inserted near the middle of the 
front. The claws of the males are long and cylindrical : such is the 
Gonoplax, Leach. 
Two species of which are found in European seas ; one of them, 
however, may possibly be a mere variety of the other. 
The first — Cancer angulatus, L. ; Herbst., I, 13 ; Leach, Ma- 
lac. Brit., XIII, has the anterior angles of its shell prolonged 
into a point, and a second, but smaller spine behind. Two 
others are observed on the claws of the males, one on the joint 
called the arm, and the other on the internal side of the carpus ; 
the hands are elongated, and somewhat narrowed at base ; ano- 
ther tooth is found on the superior extremity of the thighs of the 
other feet. The body is reddish. It inhabits the western coast 
of France, and that of England. 
In the second — Cancer rhomboides , L., the shell presents no 
other spines than those formed by the prolongation of the ante- 
rior angles. The body is smaller, and of a reddish-white or 
flesh colour. From the rocky localities of the Mediterranean f. 
In the second division of the Quadrilatera, the fourth joint of the 
external foot jaws, or those which cover the other parts of the mouth 
below, is inserted in the middle of the extremity of the preceding 
joint, or more outwardly. 
* See also the suhgenus Ocypode. I have made a new one called Trichodac- 
TYLUS, with a fresh-water speeies from Brazil, analogous to the preceding ones, 
but with an almost square shell, the third joint of the external foot-jaws forming an 
elongated triangle hooked at the end, and the tarsi covered with a close down. 
The Graspus lesselatus, of the pi. (ccev, 2) of Nat. Hist., Encyc. Method., is also 
the type of the new genus Meha, but one of too little importance to be treated of 
in detail in a work like. this. 
t See the article Rlwmbillc, Encyc. Methodique. 
