Porcellanidae, Haworth, 1825

Wicksten, Mary K., 2012, Decapod Crustacea of the Californian and Oregonian Zoogeographic Provinces 3371, Zootaxa 3371, pp. 1-307 : 153-154

Key to species of family Porcellanidae

1. Chelipeds markedly unequal in size, shape; thick and more or less roughened..................................... 2

– Chelipeds more or less equal in size, shape; flattened......................................................... 4

2. Carapace with tuft of plumose hairs on front. Chelipeds covered by velvet-like pubescence........ Pachycheles holosericus

– Carapace without tuft of plumose hairs on front. Chelipeds either with few, coarse hairs or with short pubescence interspersed with tufts of longer hairs................................................................................ 3

3. Chelipeds tuberculate above, without short pubescence, few if any setae in gape of fingers............. Pachychelesrudis – Chelipeds granulated, with short pubescence, dense pubescence in gape of fingers................ Pachycheles pubescens

4. Carapace markedly wider than long, chelipeds with dense fringe of setae on outer surface....... Polyonyx quadriungulatus

– Carapace about as wide as long, chelipeds without dense fringe of setae on outer surface............................. 5

5. Carpus of cheliped elongated, more than twice as long as wide................................................. 6

– Carpus of cheliped short, less than twice as long as wide...................................................... 7

6. Carapace with short transverse striations, flattened tubercles................................... Petrolisthes rathbunae

– Carapace anteriorly with granules, without striations, posteriorly smooth...................... Petrolisthesmanimaculis

7. Carpus of cheliped without lobe on anterior margin, anterior and posterior margins subparallel....... Petrolisthes eriomerus

– Carpus of cheliped lobed on anterior margin................................................................ 8

8. Carpal lobe occupying proximal 0.25 of anterior margin, anterior, posterior margins otherwise subparallel; merus of pereopod 4 not inflated. (Rarely found north of Point Conception , California)............................ Petrolisthes cabrilloi

– Carpal lobe not confined to proximal 0.25 of anterior margin of chelipeds, anterior, posterior margins converging distally; merus of pereopod 4 inflated. (Usually found north of Point Conception , California ................. Petrolisthes cinctipes