Settlement of antitrust claims against Hartz Mountain Corp. helped boost profits substantially for A. H. Robins Co. in the fourth quarter, the Richmond-based pharmaceutical company said yesterday.

Earnings for the quarter were $22.8 million (87 cents a share) compared with $5.5 million (22 cents) a year earlier as sales rose to $107 million from $96 million.

For all of 1979, Robins earned $44.7 million ($1.71) vs. $29.9 million ($1.15) as sales increased to $386 million from $357 million. Net income for the recent quarter and full year included $14.9 million (57 cents) from settlement of the antitrust claims.

Bowl America Inc. reported second quarter fiscal year profits of $443,045, (32 cents) a 10 percent increase over the same quarter last year. For the six months ending Dec. 30, the company reported profits of $385,395.

Fair Lanes Inc. reported a slight profit decline for its second fiscal quarter. Profits dropped from $1.69 million (33 cents) in 1978 to $1.51 million (31 cents) in 1979.

Fair Lanes said the profits drop was related to a land sales transaction of a subsidiary. Income rose to $14 million, up from $13.1 million for the same quarter in 1978.