11.   The dorsal arm plates are fan shaped and separated.

12.   The dorsal arm plates are fan shaped to rounded triangular and contiguous proximally.

13.   The dorsal arm plates are fan shaped with an acute proximal angle and separated.

14.   The dorsal arm plates are fan shaped, contiguous proximal, but well separated distally.

15.   The dorsal arm plates are fan shaped, much wider than long and separated from one another.

16.   The dorsal arm plates are fan to bell shaped not contiguous sometimes with a finely rugose distal edge.

17.   The dorsal arm plates are roundly hexagonal and contiguous proximally.

18.   The dorsal arm plates are slightly bell shaped or fan shaped, they approach but are not quite contiguous.

19.   The dorsal arm plates are triangular and separated.

20.   The dorsal arm plates are wider than long, rectangular and contiguous.