EXPLANATION OF PLATE XX. 



All the ilniwiugs were made by J. Heury Blake. 



Fig. 1. (6050) (HPalecphoraprii-valens. 

 •2. (oOSd) (f ) Palaphrodes irregiilari.s. 



3. (13584) (i) Palecpliora coiuiiiiniis. 



4. (9900) Cf) Aporema priBStrictmii. 



5. ((i2) (■!) Petrolystra gigaiitea ?. 



6. (411) (1) Petrolystra gigaiitca. (Copied 



by Zittel, Handb. d. paheoiit., Fig. 9'J.i.) 



7. (41-2) ( 1 ) Petrolystra gigautea. 



8. (11829) ({) Petrolystra licros. 



9. (112.;7) (f) A small lly. foiiud on the same 



stone with tbe next, jierhaps belongiug 

 to tbe Tacbydroniida', but whose precise 

 affinities it is perhaps impossible to 

 trace. 

 706 



Fig. 10. (11237) (t) Palecphora niacnlata. 



11. (0484) (f ) Palecpb.ra marvinei. 



12. (6484) (^) Palecpliora marvinei. 



13. (6484) (f) Palecphora marvinei. 



14. (11771) (^) Princcphi.ra balteata. 



15. (609) (',-) Palecphora iuoruata. 



16. (562) (I) Palaphrodes cincta. 



17. (3.534) (t) Palecphora niacnlata. 



18. (43) {'i) Palaphrodes irn gnlaris. 



19. (6639) (V) Jassns ? latcbr*. 



20. (13570) (f) Palecphora cominnnis. 



21. (159) (V) Palecphora cominnnis. 



22. (1.121) Ci) Lithecphcra seligera. 



