488 Stimpson on the Crustacea and Echinodermata 
DECAPODA MACROURA. 
Trier THALASSINIDEA. 
GEBIA PUGETTENSIS, Dana. 
Plate XXI. f. 2. 
Gebia Pugettensis, Dana; U.S. Exploring Expedition, Crust. i.510, Pl. XXXIL 
Gebia Californica, Stimpson ; Proc. Cal. Acad. Nat. Sci. i. 88. 
The Gebia may be distinguished from the other fossorial 
Macroura of this coast, by its rough, hairy rostrum, and 
equal anterior feet. 
The thumb in this species (see the figure) is considerably 
curved, and bears on its inner side a strong tooth. This 
tooth is a prominent character in all the very numerous 
specimens in the Smithsonian Museum, but is obsolete in 
the specimen described by Dana, although actual compari- 
son shows them to be the same. The species attains 4 
large size, the dimensions of an Oregon specimen being as 
follows :— 
Length of the animal . .. . Aeon. v DO E 
" u oy ios 
& c T ; : : : LU P Oe 
Wh " nex. 4 —. 5 (5 o * 
= * — abdomen r : : : . dd rome 
< «^ud ooon A “ 
A curious parasitic bivalve, apparently new, both -— 
genus and species, is frequently found adhering by -" 
byssus to the inner surface of the abdomen of this crus 
tacean. It approximates in character to the genus Lepton 
Gebia Pugettensis is found on the whole coast from 
Puget Sound to Monterey. It excavates its subterranean 
chambers in the sand and mud of beaches, near low-water 
mark, preferring that which is more or less indurated. 
