from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A tubelike structure in the body of a shelled cephalopod, such as a nautilus, extending through each chamber of the shell.
- n. A tubular organ on the abdomen of an aphid, from which a waxy fluid is secreted as a pheromone when the insect is attacked. Also called cornicle.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A strand of tissue passing longitudinally through the shell of a cephalopod mollusk, used primarily in emptying water from new chambers as the shell grows.
from the GNU version of the Collaborative International Dictionary of English
- n. The tube which runs through the partitions of chambered cephalopod shells.
from The Century Dictionary and Cyclopedia
- n. In zoöl:
- n. A siphon; especially, the siphon or funnel of tetrabranchiate cephalopods, between the chambers of the shell which it connects. See cut under Tetrabranchiata.
- n. In entomology, same as nectary, 2. Also called cornicle, honey-tube, siphonet, and siphunculus.
- n. In the cephalopods, the calcareous tubular wail of the siphon.
- n. The protrusible portion of the mouth-parts of a true louse, supposed to be modifications of the epipharynx and hypopharynx.
The foramen here described is easily seen; but, as I have stated, there are other modes of communication between the so-called pericardium and the cavity with which the siphuncle communicates, of a far more extensive nature.
It has altered the position of the siphuncle, has placed it in the centre instead of leaving it on the back, but it still whirls its spiral logarithmically as did the Ammonites in the earliest ages of the world's existence.
_siphuncle, _ which thus connected the smallest or aphical chamber with the largest.