| The basic body form of sponges consists of numerous small incurrent canals called ostia and one or more large excurrent opening called oscula. |
| Concurrent with this, the entire pectinirhomb becomes greatly protuberant along a large, thinwalled ridge spanning the incurrent and excurrent half rhombs. |
| Below it is the more fleshy languette or curtain valve which closes the incurrent siphonal opening when required. |
| Water containing minute food particles is admitted through the incurrent siphon into the pharyngeal basket. |
| The residual difference of CHF 2.0 million is accounted for mainly by changes in accounts payable and deferrals incurrent during the year. |
| Its food consists of microscopic organisms which are taken in through the incurrent siphon. |
