(Fig. 27 H, I)
Crangon franciscorum Stimpson, 1856: 97. — Rathbun 1904: 120, fig. 61. — Kozloff 1974: 164. — Chace & Abbott 1980: 574. — Jensen 1995: 40, fig. 57. — Kuris et al. 2007: 636, pl. 316 F.
Crago franciscorum. — Schmitt 1921: 92, fig. 62. — Johnson & Snook 1927: 313, fig. 267. — MacGinitie & MacGinitie 1968: 275.
Crangon (Neocrangon) franciscorum. — Zarenkov 1963: 1764.
Crangon franciscorum franciscorum. — Butler 1980: 101.
Diagnosis. Exoskeleton smooth, thin. Rostrum short, not reaching cornea of eye, apex rounded. Carapace with one dorsal median tooth, also hepatic, branchiostegal, moderate pterygostomian teeth. Eye small, pigmented. Stylocerite exceeding first segment of antennular peduncle. First segment of antennular peduncle with distal spine. Scaphocerite with lateral tooth exceeding blade. Third maxilliped setose, with exopod. Pereopod 1 with inner spine on merus; hand of subchela elongate, dactyl closing almost longitudinally against inner tooth. Pereopod 2 slender, chelate. Pereopod 3 slender, with simple dactyl. Pereopods 4, 5 setose, more robust than third, with simple dactyls. Abdominal pleura 1–4 with blunt to rounded pleura, somite 5 with posterolateral tooth, somite 6 with moderate posteroventral tooth. Abdominal somite 6 slender, with ventral groove. Telson narrow, with 2 pairs lateral spines, acute apex, shorter than uropods. Male total length 49 mm, female 68 mm.
Color in life. Mottled gray.
Habitat and depth. Sand, mud, bays, estuaries, intertidal zone to 91 m.
Range. Resurrection Bay, Alaska to San Diego, California. Type locality San Francisco Bay, California.
Remarks. Butler (1980) treated C. franciscorum as two separate subspecies, C. franciscorum franciscorum and C. franciscorum angustimana Rathbun, 1902. The latter, having a more slender subchela than the former (6–8 times as long as wide versus 4–5.5 times as long as wide), was reported from Kachemak Bay, Alaska to Tillamook Rock, Oregon. It seemed to inhabit deeper, cooler, more saline water than the typical form. There has been no subsequent study to determine if these two purported subspecies are valid.