XXVI 
SYSTEMATIC INDEX. 
Page 
Family ISCHNACANTHIDiE.20 
Ischnacanthus. 20 
—-gracilis.21 
Family DIPLACANTHID.E. 22 
Diplacanthus.23 
-striatus.24 
-longispinus.26 
Clima tius.28 
- reticulatus.28 
-scutiger.29 
-uncinatus.30 
-macnicoli.30 
-grandis.31 
-gracilis.32 
-(?) ornatus.32 
-(?) latispinosns.33 
Parexus.33 
- incnrvus .... 34 
-falcatus.34 
Subclass H0L0CEPHALI. 
Order CJHIMiEROIDEI . . . 
Family PTYCTODONTIME . 
Ptyctodus. . . . 
Rhynchodus . . . 
Palseomylus . . , 
36 
36 
37 
38 
39 
39 
Family SQUALORAIID^E 
Squalor aj a . . 
-polyspondyla 
-tenuispina 
40 
40 
41 
43 
43 
Cbalcodus 
