urielgc's Identifications

Identified using "Key to the Caprellidae of the West Coast of North America" https://www.scamit.org/tools/toolbox/Phylum%20Arthropoda/Class%20Malacostraca/Order%20Amphipoda/Family%20Caprellidae/Other%20Useful%20Tools/*Key%20to%20the%20Caprellidae%20of%20the%20West%20Coast%20of%20North%20America.pdf
3->10 Ventral spine lacking between insertions of Gnathopod 2
10->11 Cephalon smooth, no distinct spines or tubercules
11->12 Cephalon, pereonites I and II, and Gnathopod 2 not setose; lateral border of pereonites III and IV lacking spines
12->13 Propodus of peropods with one pair of grasping spines
13->14 Propodus of pereopods relatively stout, grasping spines proximal to middle of palm; basis of male Gnathopod 2 not longer than propodus, dactyl not setose
14->15 Flagellum of antenna I multiarticulate, flagellum of antenna II at least biarticulate; body usually not markedly compact
15-> 16 Propodus of Gnathopod 2 with less than two accessory spines at base of grasping spine; in male, gnathopod 2 propodus without antero-dorsal projections; pereonite I not more than twice as long as head
16->18No dorsal spines or tubercles present; antenna 1 less than half body length
18->Gills long, oval; in male, Gnathopod 2 not setose, poison spine enormous; in female, Gnathopod 2 attached at anterior end of pereonite II

Gnathopod 2 = the large, raptorial appendages
Cephalon = the "head"
Pereonites = the long, tube-shaped body segments after the head
Propodus of pereopods = referring to the most distal segment of the hind legs, just before the claw-like dactylus
Basis = the segment at the base of the gnathopod
Antenna 1 = 1 the longer pair of antennae
Gills = the oval, paired projections in the middle of the body