42 BULLETIN OF THE LABORATORIES 



Plate IX. 



Fig. I. Ilyocryptus spinifer, Her., female. 

 Fig. 2. Post-abdomen of same. 

 Fig. 3. Antenule of same. 

 Ftg. \A. Jaw of /. sordidiis. 

 Fig. 4. Post-abdomen of same. 



Post-abdomen of /. agilis. 



Head of same, antennae being removed. 



Antenule of /. sordidiis. 



Spines on edge of shell of same. 



Post-abdomen of /. acuiifrons. 



Monospihis dispar, female. 



I^lg. 



5- 



Fig. 



6. 



Fig. 



7- 



Fig. 



8. 



Fig. 



9- 



Fig. 



IC 



