It's probably easier to define what is NOT cryptozoology. Cryptozoology does not refer to ghosts or animal apparitions. If you come across a report that includes UFO's or psychics, just throw it out. Cryptozoology is not about newly-discovered small animals. I'm not stating that these discoveries are not interesting or not worth reporting, but this is not cryptozoology.
Small organisms have an appeal of their own, but they are by no means uncommon.
It's just a matter of taking the time to catalog them. This is one area that is slightly clouded. These include large reptiles, exotic mammals, and large birds. In many cases, exotics are mistaken for undescribed animals. Crypto-enthusiasts have a penchant for disregarding the exotic pet trade, usually because they have no background in it and have no interest in doing some basic research.