156 STALK-EYED CRUSTACEA 



c. Spines on inferior orbital border. 



10. Inferior orbital border has three teeth. — {P 

 reticnlatus.) 



11. Tubercles upon carapace fungiform. Two teeth 

 on inferior orbital border. — {P. fragosus.) 



I. Pilumnus aculeatus. 



Pilumnus aciilcatiis . Say, A. Milne Edwards, Miers, 



H. Milne Edwards, Gibbes, 

 Stimpson, Kingsley. 



The front is formed of two lobes, separated in the 

 middle line by a deep notch, another wider notch separates 

 them from the orbital angles ; each of them has upon 

 their anterior border three or four spines. The external 

 orbital angle has two similar spines ; one internal or 

 frontal, directed forwards ; the other external, directed 

 a little outwards. The superior and inferior orbital 

 border have spines. The antero-lateral border of the 

 carapace has four spines stronger than the preceding ; 

 the first forms the external orbital angle. There is, 

 in the space that separates the first from the second 

 spine, a small spine upon the border of the sub- 

 hepatic region, its point being visible on a dorsal 

 view ; these antero-lateral spines are sometimes bifur- 

 cated. The hepatic region has usually two or more 

 spines above. 



The first pair of legs, large, of unequal size, is very 

 spiny above; this armature disappears more or less upon 

 the inferior part of the external face of the pincers. The 

 walking legs are strong; the fourth joint has above very 

 small spines ; those on the fifth are larger and arranged in 

 two rows. 



