The species known as the network executive (networkitus executivus) is unique in the world of nature. Seemingly human in stature and characterization, the network executive is unusual in the sense that its brain is seated firmly in its tushie region. As this area of the executive's body gets the least amount of blood during an average day this leads to some very strange programming decisions. Thus, the reason that viewers were entertained by Cop Rock, Who Wants to Marry a Millionaire? and that sitcom that starred Emeril.

This lack of blood also causes memory loss. At least, that's what I believe it does because it's the only way I could think of that NBC would hire Ben Silverman to co-chair the entertainment division. Or, rather, hire another man named Silverman to help program their primetime schedule. For, if their memories were working properly, they would have realized that another man with the last name of Silverman came to the NBC 30 years ago and proceeded to muck everything up as well.

The buttoned down mind of Bob Newhart is coming back to TV. In August, Hallmark Channel will present Newhart in Herb's Murders, a two-hour original TV movie. And that's not all. Hallmark, which yesterday announced Jane Seymour in a detective movie called Dear Prudence, has other old TV favorites slated for original telefilms.

There's former 7th Heaven star Stephen Collins will star in The Ride of Her Life; Jacqueline Bisset has a holiday pic in the works called Thanksgiving Reunion, which will air in November; and Pam Grier, Florence Henderson (The Brady Bunch) and Donna Mills (Knots Landings) will headline Ladies of the House, about three women from the same church who team up on a home renovation project.