PLATE CXLIV. 



Icot<ypus arcurostris (p. 886). 



Fig. 1. Lateral view ; enlarged ten times. 

 „ Id. Mandible. 

 ,, If Second siagnopod. 

 „ \g. Third siagnopod. 

 ,, 1 br. Branchial plume. 

 „ lc. Cephalon. 



Hectarthropus exilis (p. 889). 

 „ 2. Lateral view ; enlarged ten times. 

 „ 2t. Fifth somite ; dorsal aspect. 



Hectarthropus compressus (p. 891). 

 „ 3. Lateral view ; enlarged eleven times. 



Hectarthropus expansus (p. 892). 

 ,, 4. Dorsal view ; enlarged twelve times. 

 „ 5. Lateral view ; enlarged twelve times. 



Hectarthropus tenuis (p. 893). 

 „ 6. Lateral view ; enlarged ten times. 



