30 
Natural History 
Tribe PORCELLANIDEA. 
Genus Petrolisthes Stimpson. 
Proc. Acad. Nat. Sci., Phila. , 1858. 
Carapax depressed, subovate, not wider than long, front triangular, margin 
more or less undulate, dentate or entire. Eyes fairly large. Peduncle of 
antennae more or less cristate. Chelipeds wide and flattened. Dactyls of 
ambulatory feet normal, i. e., short, rather strong and with a single hooklet. 
Petrolisthes rupicolus Stimpson. 
Porcellana rupicola. Joun. Bost. Soc. Nat. Hist., Vol. VI., 1857, p. 480. 
Petrolisthes rupicolus. Stimpson. Proc Acad. Nat Sci., Phila., 1858. 
Carapax depressed, front triangular with a blunt extremity. Surface of 
the feet and anterior half of the carapax scarcely rugose with granules 
but slightly prominent. External antennae one and a half times 
as long as the carapax. Anterior feet large and broad, margins smooth. 
Surface of the carpus granulated, but not tuberculated. Pincers smooth 
with somewhat hooked extremities. Colour, dark purplish red. 
Under rocks at low water Victoria, common. Straits of Georgia, Baynes 
Sound near Comox, and Clayoquot Sound, West Coast of V. T. (C. F. N ) 
Provincial Museum, Victoria. 
Genus Pachycheles Stimpson. 
Proc. Acad. Nat. Sci., Phila., Dec., 1858. 
Carapax round ovate, length not greater than the width, epimera free 
posteriorly, the posterior part quadrate and separated by a cutaneousi nter- 
val. Front not particularly prominent in the middle, subacute. First 
joint of the antennae not at all produced. Chelipeds very thick and rugose, 
with a short carpus. Dactyls of the ambulatory feet normal. 
P. rudis Stimpson. 
Ann. Lyc. Nat. Hist. N. York, Vol. VII., p. 76, f. 5, 1860. 
Carapax glabrous, obsoletely granulated, punctate or striate in different 
parts. Chelipeds very unequal, with a rugose uneven surface above, irregu- 
larly tuberculated and granulated, carpus short and angular, its surface 
strongly granulated and with two rows of tubercles more prominent than 
the rest. 
At low water, rare, Victoria, (G. W. T. & C. F. N.) Roots of kelp Clay 
oquot, common, (C. F. N.)— Provincial Museum, Victoria. 
