- siphuncle
[siphuncle 词源字典]
- "(In shelled cephalopods such as nautiloids and ammonoids) a calcareous tube containing living tissue running through all the shell chambers, serving to pump fluid out of vacant chambers in order to adjust buoyancy", Mid 18th century: from Latin siphunculus 'small tube'.[siphuncle etymology, siphuncle origin, 英语词源]