FOUR-HORNED SPIDER-CRAB. 28 



pace ; it is formed of two strong horns, diverging for about 

 one-third of their length, and slightly deflexed ; the lateral 

 margin has four spines, exclusive of a very strong one above 

 the orbit, and a smaller one behind that cavity. There are 

 numerous tubercles on the carapace, several small ones 

 on the gastric region, disposed transversely ; one on the 

 centre of the carapace ; two considerable ones on each 

 branchial region, one on the centre of the cardiac, and 

 a small one near the posterior margin. The spines above 

 the orbit are triangular, very strong and prominent ; di- 

 rected forwards and a little outwards, and so formed that 

 the eyes can be deflexed within them, so as to be quite 

 concealed from above. The external antennae are beset at 

 their base with long club-shaped hairs. The anterior pair 

 of feet in the male are exceedingly strong and thick, the 

 hands especially are nearly as broad as they are long. The 

 fingers meet at the points ; the outer edge of each being 

 denticulated, and the moveable one has a small round 

 tooth. The arms and wrists have several round tubercles. 

 In the female these feet are very small, and shorter than 

 the second pair, and in the immature male they are very 

 similar to those of the female. The remaining feet are of 

 moderate size and length, the second pair being but little 

 longer than the carapace, and the fifth pair shorter than 

 its breadth. There are a few tubercles, and a few small 

 spines upon the legs, and the nail is furnished beneath with 

 a regular row of sharp spines arranged like the teeth of a 

 comb. The abdomen has seven distinct joints in each sex; 

 that of the male being broadest at the third joint ; the 

 sixth is broader than the fifth, and the seventh is trian- 

 gular. Each joint has a central tubercle. 



The abdomen of the female is very large and broad, and 

 has a broad carina. The whole surface of the shell, and 



