=Cten-oph´o-ra= [Gr. _kteis_, comb; _phero_, bear.] A subdivision of cœlenterates with paddle-like locomotive plates arranged in eight meridional rows on the outer surface of the body. =Cyc-a-da´ce-æ= [Gr. _kykos_, African coco-palm.] The cycad family of plants (gymnospermous), of fern-like or palm-like aspect. =Cys-toi´de-a= [Gr. _kystis_, bladder; _eidos_, form.] =Cy-no-ceph´a-lus= [Gr. _kyon_, dog; _kephale_, head.] =Cy´to-plasm= [Gr. _kyo_, be pregnant; _plasma_, < _plasso_, form.] Protoplasm; especially that portion of a cell apart from the nucleus. =Dal´ton-ism= [Dalton, chemist, who had color-blindness.] Color-blindness, especially red-blindness. =De-cid´u-ate= [Lat. _deciduus_, falling off.] Shed at periodic times. =Des´mids= [Gr. _desmos_, band.] Unicellular plants of minute size; bright-green in color; mainly solitary, fresh-water algæ. =Dev-o´ni-an= [Devonshire, England.] The name given by Murchison to Palæozoic rocks in Devonshire, England. =Di´a-toms= [Gr. _dia_, through; _tome_, cutting.] Microscopic unicellular algæ inhabiting salt or fresh water. Each individual (frustule) consists of two flint valves which are more or less symmetrical. They are either isolated or attached together in a series. =Di-cot-y-le´don-es= [Gr. _dikotylos_, with two hollows.] The most important and largest class of flowering plants. Characterized by having seeds with two cotyledons, exogenous stems, and leaves that are netted-veined; the parts of the flower mostly in fours or fives. =Di-del´phi-a= [Gr. _di_-, two; _delphys_, womb.] A sub-class of mammals, as the Marsupials, having a double womb and no placenta. =Dif-flu´gi-a pyri-form´is= [Lat. _diffluere_, to flow apart; _pyrum_, pear; _forma_, form.] =Di-no-sau´ri-a= [Gr. _deinos_, terrible; _sauros_, lizard.] Mesozoic land reptiles. =Dip´no-i= [Gr. _di_-, two; _pneo_, breathe.] Fishes with regular gills, a double or single lung, and nostrils inside as well as outside the mouth. =Dro-ma-the´ri-um= [Gr. _dromos_, running; _therion_, small wild beast.] =Dys-chro-ma-top´si-a= [Gr. _dys_, bad; _chroma_, color; _opsis_, sight.] Partial color-blindness; difficulty in distinguishing colors. =E-chi-no-der´ma-ta= [Gr. _echinos_, hedgehog; _derma_, skin.] =E-chi´no-derms= [Vid. Echinodermata.] =Ech-i-noi´de-a= [Gr. _echinos_, hedgehog; _eidos_, form.] Echinoderms including sea urchins. =Ec´to-derm= [Gr. _ektos_, outside; _derma_, skin.] =Ec´to-plasm= [Gr. _ektos_, outside; _plasso_, form.] =E-den-ta´ta= [Lat. _e_, out of; _dens_, tooth.] An order of placentals with a small, one-lobed cerebrum; without median, cutting teeth: including armadillos, ant-eaters, and sloths. =El-as-mo-bran´chi-i= [Gr. _elasmos_, metal plate; _branchia_, gills.] Fish-like vertebrates which have no membrane bones in the skull or the shoulder-girdle; five pairs of strap-like gills attached by their distal ends; claspers to the ventral fins of males; complicated brain with optic nerves forming a decussation.