278 GEO. H. HORN. 



EXPLANATION OF PLATE III. 



Fig. 1. — Head and claw of Helochares. 

 " 2 — Philydrus, showing the series of punctures. 

 " 3. — Philydrus (Enochnis). 



4. — Philydrus cousors % , claws, niesosterual plate and penis. 

 " 5. — Philydrus cinctus % , same details. 



6. — Philydrus perplexus '^ , same details. 



7. — Philydrus carinatus 'J, , same details. 

 " 8. — Philydrus californicus '^ the two claws on each pair of feet, mesoster- 



nal plate and penis. 

 " 9. — Philydrus Hamiltoni '^ , same details. 

 " 10. — Philydrus fucatus %, , details as in 4. 

 " 11. — Philydrus diffusus % , details as in 8. 

 " 12. — Philydrus reflexipenuis % , same details. 

 " 13. — Philydrus nebulosus, claws of % and penis, mesosternal plates showinj; 



variation, sexual and otherwise. 

 " 14. — Philydrus ochraceous, mesosternal plate. 

 " 15. — Heloconibus bifidus %, head and claws. 

 " 16. — Philydrus, posterior leg. 

 " 17. — Cymbiodyta, posterior leg. 



" 18. — Cymbiodyta, mesosternum as seen from a posterior view ; n, lacustris : 

 6, fimbriata; c, morata ; d, fraterculus ; e, marginella. 



EXPLANATION OF PLATE IV. 



Fig. 1. — Head of Hydrobius, antenufe a little too large. 



2. — Hydrobius fuscipes, femora as seen beneath. 



" 3. — Hydrobius tesselatus, idem. 



" 4. — Hydrobius globosus, idem. 



5. — Hydrobius latus, idem. 



" 6. — Hydrobius scabrosus, idem. 



'• 7. — Hydrobius tumidus, idem. 



" 8. — Creniphilus infuscatus. idem. 



" 9. — Creniphilus dieestus, idem. 



" 10. — Hydrobius, right posterior tibia, under view. 



" 11. — Creniphilus, idem. 



" 12. — Creniphilus monticola, head and palpi. 



" 13. — Creniphilus dissimilis, idem. 



" 14. — Creniphilis dissimilis, coloration of thorax. 



" 15. — Creniphilus monticola, idem. 



" 16. — Creniphilus infuscatus, idem. 



" 17. — Creniphilus monticola, antenna. 



" 18. — (Creniphilus subcupreus, idem. 



" 19. — Creniphilus despectus idem. 



" 20. — Creniphilus digestus idem. 



" 21. — Helopeltis, head and palpi. 



