| 1a |
a. Margins
of protarsal claws densely covered with spines (> 30) that are
only slightly smaller than the short terminal spines |
Metretopus
borealis (Eaton) |
| b. Outer
margin of Ab4 gill with 2-7 stout spines in addition to small setae |
| note: rare |
| 1b |
a.
Margins of protarsal claws sparsely covered with spines (< 20)
that are more slender than the long terminal spines |
Siphloplecton Clemens,
2 |
| note:
widespread |
| |
| 2a(1b) |
a. Median ventral
stripe of abdomen continuous, uninterrupted |
Siphloplecton
basale (Walker) |
| b. Mesotarsal claw
10x as long as wide at base |
| 2b |
a. Median ventral
stripe of abdomen interrupted at each intersegmental suture |
Siphloplecton
interlineatum (Walsh) |
| b. Mesotarsal claw
7-8x as long as wide at base |