The Grantia Canal System is called the "Sycon (syconoid) Canal System." This means that the canals from the sponges inside (excurrent canals) and those from the outside (incurrent canals) of its body wall end blindly, but are connected at right angles by openings called prosopyles. This type of canal system is intermediate in canal complexity. The canals are the pathways the water takes through the sponge.
The alimentary canal and the accessory organs
Compact bone consists of a repeating structure called a Haversian system, or osteon, which is the primary anatomical and functional unit. Each osteon has concentric layers which are deposited around a central canal, also known as the Haversian canal, each containing a blood and nerve supply.
The alimentary canal performs all the functions of preparing eaten food for absorption into your body, Without it, their would be no digestive system or digestion. Life would not be possible.
http://content.answers.com/main/content/img/oxford/Oxford_Food_Fitness/0198631472.alimentary-canal.1.jpg
The fate of archenteron is that it develops into alimentary canal, and the digestive system organs in higher animals.
Grantia compressa was created in 1780.
Porifera. http://en.wikipedia.org/wiki/Grantia
There are many features that distinguish grantia as an animal. The main feature is locomotion which is a key feature for animals.
3
It's asymmetrical.
Grantia belong to the class Calcarea, a class of marine sponges characterized by their calcareous (calcium carbonate) spicules. They are filter feeders that are commonly found in shallow coastal waters.
The Hohokam Canal System.
upright
Alimentary Canal
The Hohokam Canal System
they curl up
Alimentary Canal