SIPUN'CULUS, a genus of echinodemnata, giving its name to a family, mpuncsdacee, and to an order, sipunculide. The sipunculide, although ranked among the radieke, and having the essential characters of that division of the animal kingdom, resemble the annelida in form, general appearance, motions, and habits, as well as in their softer covering, which is leathery and not calcareous, and in the absence of calcareous spines. The .syunculacete have a retractile proboscis, around the extremity of which is a circle of tentacula, and at the base of it the anus. In the genus sipainetaws the proboscis is long and cylindrical, with a circle of tentacula near its extremity. S. Bernhardus is tom mon on many parts of the British coast, living at the bottom of the sea, at a depth of from 10 to 30 fathoms, and occupying as a habitation the shell of some univalve mol lusk, for the protection of its soft wormlike body. It secures the entrance of the shell by a plaster-work of sand, leaving only a hole wide enough for the protrusion of its long flexible proboscis. Other species, instead of sheltering themselves in shells, burrow in the sand. Among these is the EDIBLE SIPITSCIMUS (S. much esteemed
by the Chinese.
SIR (Fr. slew. and sire, contracted from seigneur; from Lat. senior, elde•), a term originally corresponding to dominos in Latin. mid which has come, when appended to the Christian name and surname, to be the distinctive mark of knighthood. It was at one time the iiractice to use the same title in addressing the clergy, a familiar instance being sir Hugh Evans in the Merry Wires of Windsor. To so great an extent did this usage obtain. that a "sir 3011n" came to he a common sobriquet for a priest. "Sir" was here a Ira nslatbal of the term used for a bachelor of arts, originally in contradistinction from the neigister, or toaster of arts, but eventually extended to the clergy without distinction. Used along with the Christian name and surname, "sir" is now applied exclusively to knights and baronets. Standing alone, it is a corn plimentary mode of address used without much consideration of rank or social status. "Sire" is another form of the same monosyllable, which has been adopted from France as a mode of addressing royalty. .