296 AUSTRALIAN HALACOSTRACA. 



posterior extremity. Peduncle of caudal appendages with a short 

 spine representing the internal ramus ; outer ramus ciliate, 

 narrow, slightly curved backwards, extending rather beyond the 

 extremity of the mesial spine, bifurcate at the tip. Plagella of 

 antennae each with about ten articuli. Length vV in. 



Port Jackson. 



511. Cilicoea crassicaudata. 



Cilicoea crassicaudata, Haswell, 1. c, Vol. v., p. 475, pi. xvii., 

 fig. 3. 



Surface finely granular. Postero-lateral angles of the thoracic 

 segments blunt. Penultimate segment of the abdomen slightly 

 swollen ; median spine rather short, not extending beyond the 

 middle of the uropoda, thick, clothed with short cilia, apex entire, 

 blunt. Last segment of the abdomen with two mammiform 

 elevations ; its posterior extremity deeply notched ; notch with a 

 low mesial lobe. Basal segment of the caudal appendages with a 

 blunt process on its inner border ; mobile ramus sub-cylindrical, 

 ciliated, curved inwards, extending beyond the extremity of the 

 median spine,, apex rounded, entire ; immobile ramus rudimentary. 

 Length \ in. 



Holborn Istand, 20 fathoms. 



512. Cilicoea hystrix. A.M. 

 Cilicoea Jii/stris, Haswell, 1. c, Vol. vi., p. 3, pi. iii., fig. 1. 



Head and body armed above with numerous slender, needle- 

 like spines. Head short and broad, armed anteriorly with close- 

 set, short, delicate spines, and with a pair of thicker bifurcate 

 horns, directed upwards, forwards, and outwards near the posterior 

 margin. Pirst segment of the thorax with a similar pair of 

 bifurcate horns, its lateral border prominent, tridentate ; follow- 

 ing segments short, each with a single transverse row of slender 

 spines, the lateral angles very acute that of the fifth segment 

 bifurcate. Pirst abdominal segment with two prominent spines 

 on its proximal dilated portion the posterior process extending 

 nearly as far as the extremity of the abdomen, forked at the tip. 

 Last segment with two rounded elevations, each armed with 



