Umbrella crab

Cryptolithodes sitchensis has a half-moon shaped carapace extending over all of its eight walking legs and two chelipeds, giving them their common names of turtle crab, umbrella crab or helmet crab. The carapace can be 5–10 cm (2.0–3.9 in) at the adult stage and has scalloped edges. This carapace ranges from neutral sandy colors to bright oranges, reds, and purples.:192, 255 The rostrum extends forwards from the carapace, gradually widening before ending abruptly. From above, only the eyes and second antennae are visible. The ventral side is commonly white in color, and the abdomen is protected my multiple hard plates that lack raised margins.:407 The chelipeds are smooth. The fifth pair of walking legs are located at the posterior, and are difficult to distinguish.