Just remember.............eight legs is cool !!!!!!!!
The Class Arachnida are the most familiar of the Arthropods outside of the ever-present insects, there are over 80,000 named species and they are united by the possession of eight legs, chelicerae and pedipalps, the lack of biting and chewing mouthparts (food is ingested in most cases as a liquid, though some help is often given the food in becoming liquid by the secretion of, or regurgitating onto or into the food of, digestive enzymes from the stomach.
The Arachnids, evolved in the sea, but now they are almost entirely terrestrial and have developed several important features to help them survive on the land. These include: a waterproof (waxy) exocuticle, internal fertilisation, malphagian tubules as a metabolic excretory system and internal organs for breathing and gaseous exchange.
The class Arachnida is extremely diverse in form and in lifestyles and little more can be said that includes them all. This diversity is reflected in the classification scheme shown below.
The Class Arachnida is divided into 13 subclasses, (or orders depending on which classification scheme you are following) of which the Araneae (spiders) and the Scorpiones (scorpions) are the best known.
Well that's it for now Folks, thanks for calling !