THE EURYPTERIDA OF NEW YORK Il5 
Eusarcus scorpionis 
_ Neanic stage [pl. 36, fig. 1] 
t Wider preabdomen 
2 Wider postabdomen 
Eusarcus (?) cicerops 
Nepionic stage [pl. 36, fig. 9] 
1 Carapace triangular with 
a Spinelike prolongations of frontal and genal angles 
6 Immense, diverging eyes 
c High median crest or glabella 
d Broad, thick border 
Pterygotus macrophthalmus 
Neanic stage [pl. 69, fig. 3, 5] 
1 Larger compound eyes 
Larger ocelli and more prominent ocellar mound 
More rapid contraction of preabdomen 
Larger swimming feet 
More spatulate telson 
mn W bd 
Pterygotus globiceps 
Nepionic and neanic stages [pl. 81, fig. 1-5] 
1 Very large carapace and very small abdomen 
2 Smaller number of abdominal segments 
The larval eyes are in this form relatively not larger than in 1 the 
adult, but provided with a prominent ring (orbital ridge) 
Hughmilleria shawangunk 
Nepionic and neanic stages [pl. 64, fig. 1-13] 
1 Larger (longer and broader) carapace 
‘Much larger compound cyes 
Larger and more prominent ocellar mound 
More slender abdomen 
smaller number of (preabdominal) segments 
mB Ww bd 
