i66 STALK-EYED CRUSTACEA 



I. Heteractaea ceratopus. 



Heteyactcea ceratopjis ... A. Milne Edwards. 

 Piluuinus ceratopus . . . . Stimpson. 



The carapace is slightly curved, and covered with 

 short brown hairs arranged in groups and not covering 

 the body uniformly. The regions are marked and have 

 tubercles or granulations ; the gastric region has only 

 some roughness corresponding to the insertion of hairs. 

 The front is almost straight, it is formed of two lobes 

 with very thick borders ; there is a small transverse 

 crest extending above and parallel with its border. The 

 superior orbital border is unarmed, and constitutes a 

 sort of strong circular pad dilated on the outside, where 

 it is continued with the external orbital angle that 

 has the appearance of a large flat tubercle ; a fissure 

 divides this pad into two portions. The inferior orbital 

 border is two-lobed ; each lobe is wide, triangular, and 

 advanced ; the external lobe is separated from the orbital 

 angle by a deep notch. 



The antero-lateral borders have three long and sharp, 

 and two small spines ; one situated behind the external 

 orbital tubercle, the other between the two first principal 

 spines ; the subhepatic region has two small spines 

 visible on a dorsal view, and a number of granulations ; 

 these latter arc also upon all the pterygostomian 

 regions. 



The legs of the first pair are of unequal size, and 

 very spiny above and on the outside. The walking 

 legs are short and very compressed ; the fourth joint 

 is spiny above ; the fifth has upon its inferior border 

 a series of very large spines ; and, a little behind, a 

 horn-shaped ridge terminating below in a long and sharp 



