SIPUNCULOIDEA  , marine animals of uncertain

affinities, formerly associated with the Echiuroidea (q.v.) in the group Gephyrea . Externally, the body of a Sipunculoid presents no projections: its surface is as a rule even, and often glistening, and the colour varies from whitish through yellow to dark brown . The anterior one-quarter or one-third of the body is capable of being retracted into the remainder, as the tip of a glove-finger may be pushed into the rest, and this retractile part is termed the introvert . At the tip of the introvert the mouth opens, and is surrounded in Sipunculus by a funnel-shaped, ciliated lophophore (figs . 1 and 2) . In Phascolosoma and Phascolion this funnel-shaped structure has broken up into a more or less definite group of tentacles, which in Dendrostoma are arranged in four groups . In Aspidosiphon and Physcosoma the tentacles are usually arranged in a horse-shoe, which may be double, overhanging the mouth dorsally . On the surface of the funnel-shaped lophophore are numerous ciliated grooves, and each of the tentacles in the tentaculated forms has a similar groove directed towards the mouth . These grooves doubtless serve to direct currents of water, carrying with them small organisms towards the mouth . The skin consists of a layer of cuticle, easily stripped off, secreted by an ectodermal layer one cell thick . Within this is usually a sheath of connective tissue, which surrounds a layer of circular muscles; the latter may be split up into separate bundles, but more usually form a uniform sheet . Within the circular muscles is a layer of longitudinal muscles, very often broken into bundles, the number of which is often of specific importance .

Oblique muscles sometimes

lie between the circular and longitudinal sheaths . On the inner surface is a layer of peritoneal epithelium, which is frequently ciliated, and at the bases of the retractor muscles is heaped up and modified into the reproductive organs . The ectoderm is in some genera modified to form certain excretory glands, which usually take the form of papillae with an apical opening . These papillae give the surface a roughened aspect; the use of their secretion is unknown . They are best developed in Physcosoma . When the body of a Sipunculoid is opened, it is seen that the body-cavity is spacious and full of a corpusculated fluid, in which the various organs of the body float . The most conspicuous of these is co-educational; founded in 1883), All Saints School (Protestant Episcopal), for girls, and a Lutheran Normal School (1889) . The city is the see of a Roman Catholic and of a Protestant Episcopal bishop . The river falls here about zoo ft. in half a mile and provides good water power for manufactures . The total value of the factory products increased from $883,624 in 1900 to 51,897,790 in 1905, or 114.8% . Sioux Falls is a jobbing and wholesaling centre for South Dakota and for the adjacent parts of Iowa and of Minnesota . A quartzite sandstone, commonly known as jasper or " red granite, " is extensively quarried in the vicinity, and cattle raising and farming are important industries of the surrounding country .

A

settlement was made at Sioux Falls in 1856, but this was abandoned about six years later on account of trouble with the Indians . A permanent settlement was established in 1867, and Sioux Falls was incorporated as a village in 1877 and was chartered as a city in 1883 .