5 (2) First pair of legs chelate (minute in some species) 6 2 



5 (2) First pair of legs subchelate (always easily visible) Family Crangonidae 15 



Figure 9. — Chelate leg with carpus entire. 



Figure 10. — Subchelate leg with carpus entire. 



6 (5) Carpus of second pair of legs entire; first pair of legs always with well-developed 



chelae Family Palaemonidae 7 



6 (5) Carpus of second pair of legs subdivided into 2 or more articles 8 



» 



7 (6) Rostrum with 6 or more (seldom 5) ventral teeth; mandible with palp Leander tenuicornis 



Figure 11. — Leander tenuicornis; A. carapace of male, lateral view: B, carapace of female, lateral view: C. mandible. 



2 Pasiphaea mullidentata (Pasiphaeidae) with fingers of chelae on first and second legs slender, all edges comblike, is a pelagic form 

 which occurs often enough off New England that its presence should be mentioned. Ovigerous females have a carapace length of 33 to 

 37 mm. 



