r--^. 



< . I. 





k'l? 



f' • -> 



^Y"'>' "f) 





FiG.^l. BalcEiK^tera musculus, see p. 3. 



Fig. 2. Neobalcena marginata, sec p. i. 



Fig. 3. Hypcroodon rostratus, see p. 5. 



To face p. 4. 



