Glass sponges, also referred to as Hexactinelled, are a third type of sea sponge. Glass sponges, similar to the other two types of sponges, don't have an endocrine system. They use chemical messages to transport hormones to other cells. The speed of receiving these also varies based on the size of the sponge;however, most glass sponges are the same size and have the same amount of tips. These hormones being sent mainly consist of short polypeptides.