434 MOLLUSCA. 
Inhabits Wallawalla, Spokane, Wahlamet, &c., Oregon, J. Drayton ; 
and Upper Sacramento River, California, Dr. Pickering. 
Mr. Lea and others have regarded this as a variety of A. margari- 
tifera. He says of specimens brought by Mr. Nuttall, “It should be 
remarked that the nacre in these specimens is always purple, a cha- 
racter not observed from other localities.” But besides the uniformly 
peach-blossom nacre, the form is generally more arcuate, the exterior 
more waved, the colour darker; the anterior tooth in the right valve 
is comparatively obsolete, longitudinally oblique and lamellar in the 
young. The young have also the sides compressed, the epidermis 
rusty brown, and a great part of the nacre white; the teeth are also 
more sharply developed. A small, distorted specimen, was short and 
much inflated. From the large heaps of dead shells observed by Dr. 
Pickering, both in Oregon and California, it is evidently used exten- 
sively for food, by the Indians. 
Figures 545, 545 a, 5455, three views of the shell. 
ANODONTA PUBERULA (Gould). 
T. transversa, elongato-ovata, ventricosa, anticé rotundata, posticé ob- 
lique rotundata et costa obliqua submarginali munita ; margine dorsal 
arcuato; margine ventral concavo; apicibus ante-medianis, acutis, 
parum elevatis ; epidermide olivaceo-glaucescente fluctuatim corrugato 
induto: cavositas argentea ; disco salmonaceo: cardo edentulus vel 
potius papilla cardinal in valva dextra instructus. 
Anodon glauca, Goutp; Proceed. Boston Soc. Nat. Hist., ii. 293. 
Noy. 1850. Expedition Shells, 87. 
SHELL transversely elongate, slightly falcate, gradually widening 
backwards, inequilateral, compressed and even excavated at the sides; 
posterior umbonal slope full, bounded above by a rib-like elevation, 
passing from the beaks to the middle of the posterior end; beaks at 
the anterior third, rather prominent, eroded; anterior end acutely 
rounded ; dorsal and siphonal ends arcuate; ventral margin concavely 
arcuate. Epidermis pale olive, radiately corrugated in festoons. 
