Page:The New International Encyclopædia 1st ed. v. 04.djvu/935

* CLASSIFICATION OF ANIMALS. S25 CLASSIFICATION OF ANIMALS. Class 5. Ckixoiuea. Sessile, and having a cup-shaped body (Crinoids). Class G. Cystoidla. Globuhir, sessile, or stalked ( Fossil ). Class 7. Bl^iSTOlDEA. Ovate, slalked (Fos- sil). Phylum IX. Anxui-vta (Worms). Bilateral segmented worms without jointed legs. Class 1. Cn.KToron.v. Orms made up of a series of nietamores, eaih bear- ing parapodia and cirri (Anne- lids). Subclass 1. I'olychccta. Sexes distinct; ovaries and testes simple and niet- anierically repeated (Jlarine An- nelids). Subclass 2. Olir/ochwta. Sexes united ; ovaries and testes few and com- pact (Terrestrial and fresh- water ). Class 2. JIyzostomida. Disk-shaped, un- segmented (Parasites of Crin- oids ). Class 3. Gepiiyrea. Sessile annelids, with- out external segmentation in the adult (Marine). Class 4. Archi-Anxelida. !Minute marine annelids, faintly segmented, often parasitic. Class 5. HiRumxEA. Annelids with short rings or none at all, and with ventral suckers (Leeches). Phylum X. Artiiropoda (Insects, Crusta- ceans, etc). Symmetrical segmented animals. With jointed appendages. Class 1. CRtST.CEA. Typically aquatic and gill-bearing; usually two pairs of antennae ( Crustaceans ). Subclass 1. Entomostraca. Usually small, and with a varied number of ap- pendages (Water-Fleas, etc.). Subclass 2. Mal^icostiaca. Crustacea with nineteen pairs of appendages (Crabs, Crayfish, etc.). Class 2. Trilobita. Body depressed, oval, and divided into head, thorax, and abdomen ( Extinct Trilobites ). Class 3. Onychophora. Cylindrical, un- .segmenteu, papillose, and with a series of short walking append- ages (Peripatus), Class 4. Mybiapoda, Tracheate arthropods, consisting of several segments, each bearing one or two pairs of legs (Centipedes and ilillipedes). Class 5. IxsECT.. Arthropods with the body in three divisions — head, thorax, and abdomen — with six thoracic legs, and usually with wings (Insects). Class 6. Araciixid.. Air-breathing ar- thropods, without antennie (Spi- ders, Scorpions, etc). Phylum XT. Moi.i.uscA (Afollusks). Ani- mals with unsegniented body, and without jointed appendages; usually with a shell, and with a muscular organ of locomotion (the foot). Note. The Pycnogonklti, LinfriatulifJa, and Tnrdlfrr/i' tja, "thouKh not ti» any way relnt**(l to one miother. nnd of ilnnhtfnl rpIntUtnflhir*** to thp .Vrnchnldn, are. rh a mat- ter of nonvenlence. mentioned together here." — Parker und Class 1. Pelkcypoda, IMollusks with a. nearly symmetrical bo<ly, leaf- like gills, and a Iwo-valved slielt (Bivalves). Class 2. Ampuixeuba. Bilaterally sym- nictrical ; anus at end of body (Chitons). Class 3. Gastkopoua. Body unsymmetrical, ith head, feelers, eyes, and un- paired foot; shell ( when present) univa he ( Gastropods ) . Subclass 1. titnptoiKttra. Visceral com- missures twisted into a figure- of-S ; sexes distinct (Limpets, helks, etc. ) . Subclass 2. Kuthijneiira. Visceral com- niisstires not twisted into a fig- uvo-of-8 ; sexes united (Pulmo- nates, Xudil>ranclis. etc.). Class 4. Sc'apiiopoda. Head rudimentary ; mouth-lobes formed into a tube, inclosing the delicate shell (Ma- rine ) . Subclass 1. Hcapliopoda. Asabove (Tusk- Shells). Subclass 2. Rhodope. Minute, ciliated: no shell. Class 5. Cephalopoda. Head large ; nioutli: surrounded by arms; foot funnel- shaped (Cuttlefish). Subclass 1. Dihratichiala. Two s nmet- rical branchiip; funnel tubular (Squids and Octopods). Subclass 2. TetrahrnnchiaUj. Four bran- chiie; shell multilocular (Xauti- lus and Ammonites). Phylum Xn. Chord.t. (Chordates). Ani- mals having a notochord, which may (Subphy- lum C) persist from birth, and become "in the adult replaced more or less completely by a seg- mented bony or cartilaginous axis — the spinal or vertel)ral column." Suhphylum und Class A. Adeeochorda. ilarine worm-like animals, hav- ing a notochord as larvae (Balano- glossus, etc. ). Suhphylum and Class B. URoriioRUA. Animals, simple or compound, marine, inclosed in a coriaceous test, composed largely of cellu- lose, and having a notochord when larva- (Ascidians). Suhphi/lum C. Vertebrata. Animals bi- laterally symmetrical, and hav- ing a backbone (Vertebrates). Sec. I. AcKAXlA. Willwut a head (in- cludes only the family Bran- chiostomid;r, Ampliioxus, etc). Sec. II, C'RAXIATA, ^yi)h a head (Fishes, Reptiles, Birds, Mammals). Class 1. C'yci.ostomata. Kcl-Iike verte- brates, without a lower jaw; mouth suctorial, and armed with homy teeth (Lampreys). Class 2. Pisces. Aquatic vertebrates, with persistent gills and paired fins- (Fishes). Subclass 1. Elasmohranchii. Fishes with a cartilaginous skeleton, in which the cranium is never ossified, nor cciUtains membrane-bones; gill- openings usually in five pairs (Sharks and Kays).