Ascon type canal system is found in:

• a. Grantia
• b. Leucosolenia
• c. Hyalonema
• d. Euspongia

The Ascon type canal system is primarily found in the sponge species known as Grantia. This type of canal system is characterized by its simple structure, where water flows directly into the central cavity called the spongocoel through small pores.

Other Sponge Types

To provide a clearer understanding, here’s a brief overview of the other options:

• Leucosolenia: This sponge has a similar but slightly more complex canal system known as the Sycon type.
• Hyalonema: This species is known for its unique structure and does not exhibit the Ascon type.
• Euspongia: Commonly known as the bath sponge, it has a more developed canal system.

In summary, the correct answer is Grantia, which exemplifies the Ascon type canal system in sponges.