390 APPENDIX. 



CLASS I. HYDROZOA. 



Sub-class i. Hydroida (" Hydroid Zoophytes"). Ex. 



Freshwater 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. Graptolitidce* (" Graptolites"). 



CLASS II. ACTINOZOA. 



Order i. Zoantharia. Ex. Sea-anemones** (Actin- 

 id&), Star-corals (Aftr&id<e). 



Order 2. Alcyonaria. Ex. Sea-pens (Pennatula), Or- 

 gan-pipe Coral (Tubipora), Red Coral (Corallium). 



Order 3. Rugosa ("Rugose Corals"). 



Order 4. Ctenophora.** Ex. Venus's Girdle (Cesium). 



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 communi- 

 cate with the exterior. Body of the adult often " radiate, " and 

 never composed of a succession of definite rings. 



CLASS I. ECHINODERMATA. 



Order i. Crinoidea ("Sea-lilies"). Ex. Feather-star 



(Comatula}, Stone-lily (Encrinus*). 

 Order 2. Blastoidea* (" Pentremites "). 

 Order 3. Cystpidea* ("Globe-lilies"). 

 Order 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. Tre- 



pangs (H olothuria) . 



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. 



