Negative-form words without corresponding positive words:

non-
	plussed
	chalant
dis-
	gruntled
	turbed
	cordent
	spicable
	sheveled
	traught
de-
	jected
in-
	soucient
	sipid
	alienable
a-
	nomalous
	nonamous
ex-
	punged
mal-
	feasance
	aprop
mis-
	ogyny
	anthropy

    Source: geocities.com/traught