Opinions from C. C. Black 1963
- 'Arctomyoides oregonensis is recombined as Protospermophilus oregonensis'
- 'Arctomys minor is recombined as Marmota minor'
- 'Arctomys minor is recombined as Marmota minor' according to R. Wilson 1937
- 'Arctomys minor belongs to Arctomys' according to Kellogg 1910
- 'Arctomys nevadensis is recombined as Marmota nevadensis'
- 'Arctomys nevadensis is recombined as Marmota nevadensis' according to R. Wilson 1937
- 'Arctomys nevadensis belongs to Arctomys' according to Kellogg 1910
- 'Arctomys vetus is recombined as Marmota vetus'
- 'Arctomys vetus is recombined as Palaearctomys vetus' according to M. Bryant 1945
- 'Citellus bensoni belongs to Citellus'
- 'Citellus cochisei belongs to Citellus'
- 'Citellus cragini belongs to Citellus'
- 'Citellus dotti belongs to Citellus'
- 'Citellus fricki belongs to Citellus'
- 'Citellus fricki belongs to Citellus' according to Hibbard 1942
- 'Citellus gidleyi belongs to Citellus'
- 'Citellus howelli belongs to Citellus'
- 'Citellus junturensis is recombined as Ammospermophilus junturensis'
- 'Citellus matachicensis belongs to Citellus'
- 'Citellus matachicensis belongs to Citellus' according to R. Wilson 1949
- 'Citellus matthewi belongs to Citellus'
- 'Citellus mckayensis belongs to Citellus'
- 'Citellus meadensis belongs to Citellus'
- 'Citellus pattersoni belongs to Citellus'
- 'Citellus pattersoni belongs to Citellus' according to R. Wilson 1949
- 'Citellus primitivus belongs to Citellus'
- 'Citellus primitivus belongs to Citellus' according to M. Bryant 1945
- 'Citellus quatalensis is recombined as Protospermophilus quatalensis'
- 'Citellus ridgwayi is a subjective synonym of Citellus tephrus'
- 'Citellus shotwelli belongs to Citellus'
- 'Eutamias ateles is recombined as Tamias ateles'
- 'Miosciurus belongs to Sciuridae'
- 'Miospermophilus belongs to Sciuridae'
- 'Miospermophilus wyomingensis belongs to Miospermophilus'
- 'Otospermophilus argonautus is recombined as Citellus argonautus'
- 'Otospermophilus argonautus is recombined as Citellus argonautus' according to R. Wilson 1949
- 'Palaearctomys bryanti is recombined as Miospermophilus bryanti'
- 'Palaearctomys bryanti belongs to Palaearctomys' according to R. Wilson 1960
- 'Palaearctomys macrorhinus is a subjective synonym of Palaearctomys montanus'
- 'Protosciurus belongs to Sciuridae'
- 'Protosciurus condoni belongs to Protosciurus'
- 'Protosciurus mengi belongs to Protosciurus'
- 'Protosciurus rachelae belongs to Protosciurus'
- 'Protospermophilus kelloggi belongs to Protospermophilus'
- 'Sciurus angusticeps is recombined as Protospermophilus angusticeps'
- 'Sciurus angusticeps belongs to Sciurus' according to Matthew 1933
- 'Sciurus arctomyoides is recombined as Arctomyoides arctomyoides'
- 'Sciurus ballovianus is recombined as Miosciurus ballovianus'
- 'Sciurus malheurensis is recombined as Protospermophilus malheurensis'
- 'Sciurus tecuyensis is recombined as Protosciurus tecuyensis'
- 'Sciurus tephrus is recombined as Citellus tephrus'
- 'Sciurus venturus is a subjective synonym of Protospermophilus quatalensis'
- 'Sciurus vortmani is recombined as Protospermophilus vortmani'