Only black widows have hourglasses on their backs... You should probably be careful
it is a blue widow
yellow widow
The name "Black Widow" comes from the spider killing their mate, plus they are black with a red or yellow hourglass.
Possibly a Black Widow. Look for a red hourglass on the belly. If there is one, it's venomous.
Barn spider?
The Black Widow Spider has either a yellow, red, or orange hourglass, but sometimes can look like a dot. Links: http://mysite.verizon.net/vzer75kc/
black spider with 2 yellow dots on its under side
hourglass
A spider with a black, furry belly is likely to be wolf spider. These spiders often have hair all over, but it can be more noticeable on the belly.
The black widow is a shiny, jet-black spider with long legs and a red or orange hourglass-shaped marking on its underside. It is about an inch long, including the legs.
The black widow spider.
that would be a black widow. very dangerous. stay away from them. not a very nice spider to get bitten by! haha It isn't a black widow. Black widows have a red hourglass shape on their belly.
It is black, and has a red hourglass-like shape on its abdomen.
It may be a Black Widow spider. They are very poisonous and it is probably best not to approach it if you are unsure of the species. Black spiders have a distinctive red "hourglass" shape on its back.