430 STALK-EYED CRUSTACEA 



b. The external antennae are some distance apart. 

 The gills are nineteen in number. The external maxilli- 

 pedes have no external appendage. — {Arches^ 



I. Ibaccus. 



Ibacais . . . Spence Bate. 



Ibacus. . . . H. Milne Edwards. 



IbacJius . . . Leach, Desmarest. 



Scyllarus. . . Fabricius, Latceille. 



The carapace, wider than long, has on each side a flat 

 prolongation which hides the greater portion of the legs. 

 These prolongations are more extensive in front than 

 behind, consequently it is broader in front than 

 posteriorly. These expansions are divided on each 

 side by a wide and deep fissure. The orbits are 

 situated at some distance from the anterior angles of 

 the carapace. The abdomen is very short, and contracts 

 from before backwards. Gills are attached to the body 

 wall, to the membranous articulation, and to the first joint 

 of all the limbs except the last pair, which have also 

 branchial plates. 



Range. — West Indies, Atlantic, New Holland, Japan, 

 Hong Kong, New Guinea, New Zealand ; in deep water, 



I. Ibaccus parrae. 



Ibaciis parrcB H. Milne Edwards. 



HorscsJioe crab (local name) . Barbados. 



The carapace and the external antennse are covered 

 with rough rounded elevations, each elevation being 

 fringed in front with a row of short hairs. The margin 

 is cut into numerous large teeth separated from each 

 other by deep and wide notches. There are two teeth 



