Animal simple or compound; body composed of "sarcode," not definitely segmented; no nervous system; and no digestive apparatus, beyond occasionally a mouth and gullet.

CLASS I.GREGARINIDÆ.**
CLASS II.RHIZOPODA.
Order 1. Monera.** " 2. Amœbea.** " 3. Foraminifera. " 4. Radiolaria (Polycystines, &c.) " 5. Spongida (Sponges).
Order1. Monera.**
"2. Amœbea.**
"3. Foraminifera.
"4. Radiolaria (Polycystines, &c.)
"5. Spongida (Sponges).
CLASS III.INFUSORIA.**

SUB-KINGDOM II.—CŒLENTERATA.

Animal simple or compound; body-wall composed of two principal layers; digestive canal freely communicating with the general cavity of the body; no circulating organs, and no nervous system or a rudimentary one; mouth surrounded by tentacles, arranged, like the internal organs, in a "radiate" or star-like manner.

CLASS I.HYDROZOA.
Sub-class 1. Hydroida ("Hydroid Zoophytes"). Ex. Fresh-water Polypes,** Pipe-corallines (Tubularia), Sea-Firs (Sertularia). Sub-class 2. Siphonophora** ("Oceanic Hydrozoa"). Ex. Portuguese Man-of-war (Physalia). Sub-class 3. Discophora ("Jelly-fishes"). Only known as fossils by impressions of their stranded carcasses. Sub-class 4. Lucernarida ("Sea-blubbers"). Also only known as fossils by impressions left in fine-grained strata. Sub-class 5. Graptolitidœ* ("Graptolites").
Sub-class1. Hydroida ("Hydroid Zoophytes"). Ex. Fresh-water Polypes,** Pipe-corallines (Tubularia), Sea-Firs (Sertularia).
Sub-class2. Siphonophora** ("Oceanic Hydrozoa"). Ex. Portuguese Man-of-war (Physalia).
Sub-class3. Discophora ("Jelly-fishes"). Only known as fossils by impressions of their stranded carcasses.
Sub-class4. Lucernarida ("Sea-blubbers"). Also only known as fossils by impressions left in fine-grained strata.
Sub-class5. Graptolitidœ* ("Graptolites").
CLASS II.ACTINOZOA.
Order 1. Zoantharia. Ex. Sea-anemones** (Actinidœ), Star-corals (Astrœidœ). Order 2. Alcyonaria. Ex. Sea-pens (Pennatula), Organ-pipe Coral (Tubipora), Red Coral (Corallium). Order 3. Rugosa ("Rugose Corals"). " 4. Ctenophora.** Ex. Venus's Girdle (Cestum).
Order1. Zoantharia. Ex. Sea-anemones** (Actinidœ), Star-corals (Astrœidœ).
Order2. Alcyonaria. Ex. Sea-pens (Pennatula), Organ-pipe Coral (Tubipora), Red Coral (Corallium).
Order3. Rugosa ("Rugose Corals").
"4. Ctenophora.** Ex. Venus's Girdle (Cestum).

SUB-KINGDOM III.—ANNULOIDA.

Animals in which the digestive canal is completely shut off from the cavity of the body; a distinct nervous system; a system of branched "water-vessels," which usually communicate with the exterior. Body of the adult often "radiate," and never composed of a succession of definite rings.

CLASS I.ECHINODERMATA.
Order 1. Crinoidea ("Sea-lilies"). Ex. Feather-star (Comatula), Stone-lily (Encrinus*). Order 2. Blastoidea* ("Pentremites"). " 3. Cystoidea* ("Globe-lilies"). " 4. Ophiuroidea ("Brittle-stars"). Ex. " Sand-stars (Ophiura), Brittle-stars (Ophiocoma). Order 5. Asteroidea ("Star-fishes"). Ex. Cross-fish (Uraster), Sun-star (Solaster). Order 6. Echinoidea ("Sea-urchins"). Ex. Sea-eggs (Echinus), Heart-urchins (Spatangus). Order 7. Holothuroidea ("Sea-cucumbers"). Ex. Trepangs (Holothuria).
Order1. Crinoidea ("Sea-lilies"). Ex. Feather-star (Comatula), Stone-lily (Encrinus*).
Order2. Blastoidea* ("Pentremites").
"3. Cystoidea* ("Globe-lilies").
"4. Ophiuroidea ("Brittle-stars"). Ex.
"Sand-stars (Ophiura), Brittle-stars (Ophiocoma).
Order5. Asteroidea ("Star-fishes"). Ex. Cross-fish (Uraster), Sun-star (Solaster).
Order6. Echinoidea ("Sea-urchins"). Ex. Sea-eggs (Echinus), Heart-urchins (Spatangus).
Order7. Holothuroidea ("Sea-cucumbers"). Ex. Trepangs (Holothuria).
CLASS II.SCOLECIDA** (Intestinal Worms, Wheel Animalcules, &c.)

SUB-KINGDOM IV.—ANNULOSA.

Animal composed of numerous definite segments placed one behind the other; nervous system forming a knotted cord placed along the lower (ventral) surface of the body.