PLATE IV. 



HISTIOSTOMA SPINIFERUM, page 215, length "26 mm., 

 and H. PULOHEUM, page 217, length "35 mm. 



Fig. 1. Histiostoma spiniferum. Adult ? , dorsal 

 aspect, X 150. 



2. Histiostoma spiniferum. Nymph. 



3. Histiostoma spiniferum. Hypopial nymph, 



dorsal aspect, X 150. 



4. Histiostoma pulclirum. Adult <? , dorsal as- 



pect, x 120. 



5. Histiostoma pulchrum. Adult ? , dorsal aspect, 



x 140. 



6. Histiostoma pulchrum. Hypopial nymph, 



ventral aspect, X 250. 



7. Histiostoma pulchrum,. Terminal joint and 



portion of the second joint of palpus, X 650. 

 A broken portion of maxillary lip is shown 

 below the palpus. 



8. Histiostoma pulclirmn. Second leg of adult 3 



from the side, X 320. 



9. Histiostoma pulclirum. Third leg of adult ? 



from above, X 320. 



10. Histiostoma pulchrum. Fourth leg of adult ? 

 from the side, X 320. 



