GENUS OCYPODE. 75 



decide without loss of time. A very good character may 

 be drawn from the lateral line; this line, which does not ex- 

 ist in the present species, arises from near the middle of the 

 edge of the thorax, passes obliquely across the side of the 

 body, and terminates at the penultimate hip joints; in the 

 two preceding species, this part is as prominent as the 

 edge of the thorax. A second good character may be 

 derived from the form and proportion of the second pe- 

 duncular joint of the external pedipalpi, in the two pre- 

 ceding species, and their congeners, this part is formed, 

 as it were, by a prolongation of the lines of the basal joint, 

 of which it is not more than half of the size; but in the 

 present species the form is altogether different, and ap- 

 proaches to that of the same part in Grapsus, and perhaps 

 Gecarcinus of Leach; it is nearly oval, a little emarginate 

 at tip for the insertion of the palpi, and inclined inwards, 

 so as to form an angle with the preceding joint, thereby- 

 leaving a considerable interval in the middle of the mouth, 

 in size also it is nearly equal. The very dense brush of 

 hair, which is attached to the inside of the third and fourth 

 pairs of hips, may furnish another character. It is not con- 

 spicuous in the species under consideration. In diis spe- 

 cies also the tibia and tarsi are not spinose as in Grapsus 

 and Gecarcinus, neither are the tarsi dilated so as almost 

 to resemble a third joint of the tibia as in the former. The 

 reticulatus in the rigid arrangement of Dr. Leach cannot 

 be referred to the Ocypodes of which the type is O. cera^ 

 taphthalma; neither will it«gree with Uca, of which the an. 

 terior feet are very unequal, nor with Goneplax, in which 

 they are very much elongated. 



By its cubical body and general habit, it certainly ap- 

 proaches the Ocypodes, £^c. but by its oral and other arti- 



