36 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY. 



EXPLANATION OF PLATES. 



All figures are of the natural size, and the originals are preserved in the 

 Museum of Comparative Zoology. 



PLATE 1. 



Figs. 1-3. Histionotophorus hassani (Zigno). Upper Eocene ; Monte Bolca. Figs. 1 



and 1 a are counterparts of tlie same specimen. 

 Fig. 4. Caranx primaevus, sp. nov. LTpper Eocene; Monte Bolca. 

 Fig. 5. Si/mphodus ssajriochae {Z\gi\o). Upper Eocene; Monte Bolca. 



PLATE 2. 

 Pygaeus agassizii, sp. nov. Upper Eocene; Monte Bolca [ex Canossa Collection). 



