THE EURYPTERIDA OF NEW YORK 309 
In tabular form the character of the three stages and the changes 
are as follows: 
NEPIONIC STAGE  NEANIC STAGE EPHEBIC STAGE 
Large Decreases in relative| Continued decrease 
Carapace........ size 
With broad border | Border becomes nar-| Border more or less 
rower........... narrow and obscure 
With immense vis-| Visual node small....} Visual node small 
ual node 
Compound eyes...| | Position submargi-| Submarginal........ Subcentral 
nal 
Visual surface rela-| Visual surface rela-| Visual surface rela- 
a OS OOF OO 
tively small . tively small tively large 
Segments 7-8...... Unknown.......... I2 
Abdomen No distinct differen-| ................... Distinct differentia- 
tiation tion 
Preabdomen..... Regularly narrowing}] ..............0005. Widest at fourth and 
posteriorly fifth segments 
(No epimera......0.] cc cece eee eee ee eee Long epimera 
Postabdomen....| | - 
All segments equally} ................0... Last segments much 
long longer 
Telson spine.....| Very short and blunt.| ................... Long and slender (?) 
Sculpture........ None... ........005 Tubercles........... Tubercles 
