
350 B. N. A. BOUNDARY COMMISSION. 
The variety campestris occurs abundantly in some pools and coulées of the 
Red River Valley, and prairie region westward. They are much larger, with 
more whorls, and only in young specimens show the teeth. Colour generally 
wax yellow or pale brown. Diameter of largest specimens from 10-5 mm. to 
12-5 mm, whorls often six, specimens to 75 mm. often, but not invariably, 
show teeth ; above this size no teeth were recognized. — 
LAMELLIBRANCHIATA. 
CoRBICULAD : 
Spherium suleatum, Lamarck. Lake of the Woods. Pembina River. 
Spherium striatinum, Lamarck. Lake of the Woods. Pembina River. 
Spherium partumeium, Say. Lake of the Woods. Dufferin. 
Spherium rhomboideum, Say. Lake of the Woods. Pembina River. 
Spherium tenue, Prime. Souris River. 
Spherium solidulum, Prime. Lake of the Woods. Souris River. East Fork Milk 
River (worn specimens). 
Spherium ? stamineum, Conrad. Pembina River. . 
Pisidium Virginicum, Bourguignat. Lake of the Woods. | 
UNIONID2 : 
For the identification of species in this family, I am indebted to Dr. P. P. Car- 
penter :— 
Metaptera alata, Lam. Red River; rare. 
Unio spatulatus, Lea. Red River. 
Unio rectus, Lam. Lake of the Woods. Roseau River. Somewhat rare. © 
Plectomerus undulatus, Barnes. (=laticostatus, Lea.) Red River. Roseau River. eet” 
Hyridella cardium, Raf. (=ventricosa, Barnes var. == subovata, Lea.) Roseau 
River. Red River; not common. 
Hyridella ligamentina, Lam. Roseau River. 
Hyridella luteola, Lam. (=—siliquoides, Barnes.) Lake of the Woods ; very com- 
mon. Souris River; very common. Roseau River; abundant. Red River. 
Pembina River. 
Lampsilis flavus, Raf. (—rubiginosus, Lea.) Red River. Roseau River. 
T heliderma quadrulus, Raf. (—Jlachrymosum, Lea.) Red River; abundant. 
Leptoidea beptodon, Raf. (= plana, Barnes. purpurascens, Swains. = tenuissima, Lea. 
Q =velum, Say.) Souris River, 
Complanaria complanata, Barnes. Souris River; abundant. Roseau River. Lake 
of the Woods ; somewhat rare. 
Complanaria costata, Raf. (rugosa, Barnes.) Roseau River ; rare. 
Uniopsis ?Ferussaciana, Lea, Lake of the Woods; abundant. 
Strophitus Pennsylvanicus, Lam. (= Anodonta rugosa, Swains. [Not Alasmodonta 
rugosa, Barnes.]=Anodonta undulata, Say. [Not Alasmodonta undulata, Say]. 
Roseau River. 
Anodonta Footiana, Lea. Souris River; very common. 
