THE EURYPTERIDA OF NEW YORK
115
Eusarcus scorpionis
Neanic stage [pl. 36, fig. 1]
- Wider preabdomen
- Wider postabdomen
Eusarcus (?) cicerops
Nepionic stage [pl. 36, fig. 9]
- Carapace triangular with
- Spinelike prolongations of frontal and genal angles
- Immense, diverging eyes
- High median crest or glabella
- Broad, thick border
Pterygotus macrophthalmus
Neanic stage [pl. 69, fig. 3, 5]
- Larger compound eyes
- Larger ocelli and more prominent ocellar mound
- More rapid contraction of preabdomen
- Larger swimming feet
- More spatulate telson
Pterygotus globiceps
Nepionic and neanic stages [pl. 81, fig. 1–5]
- Very large carapace and very small abdomen
- Smaller number of abdominal segments
The larval eyes are in this form relatively not larger than in the adult, but provided with a prominent ring (orbital ridge)
Hughmilleria shawangunk
Nepionic and neanic stages [pl. 64, fig. 1–13]
- Larger (longer and broader) carapace
- Much larger compound eyes
- Larger and more prominent ocellar mound
- More slender abdomen
- Smaller number of (preabdominal) segments