=Saur-u´ræ= [Gr. _sauros_, lizard; _oura_, tail.] Jurassic birds having lizard-like tails with distichous feathers, as Archæopterygidæ. =Sca-phop´o-da= [Gr. _skaphos_, bowl, skiff; _pous_, foot.] A division of molluscs. =Sep´al= [Lat. _separ_, separate.] One of the individual leaves of a calyx. =Si-lu´ri-an= [Silures, ancient Celts in Wales.] =Sim´i-a= [Lat. _simia_, ape.] A genus typical of Simiidæ and now restricted to the orang. =Si-mi´i-dæ= [Lat. _simia_, ape.] A family of Old World Anthropoidea. =Sim-i-i´næ= [Lat. _simia_, ape.] A subfamily of Simiidæ with robust form and molars tuberculated as in man and no ischial tuberosities, including Chimpanzees, Gorillas, and Orangs. =Si´nus veno´sus= [Lat.] Venous cavity. (1) In higher vertebrates the main part of the auricular cavity. (2) In the lower vertebrates, a dilitation at the termination of venous channels, forming a separate chamber. =Si-re´ni-a= [Lat. _siren_, siren.] =Snags= [Norw. _snag_, a projecting point.] A branch on the antler of a deer. =So-mat´ic= [Gr. _soma_, body.] Pertaining to the body. =So-ma-to-ge-net´ic= [Gr. _soma_, body; _genesis_, generation, origin.] Originating in the body or soma through external influences. =Sper-ma-to-zo´id= [Gr. _sperma_, seed, semen; _zoon_, animal.] Male germ-cell; male, flagellate, (“ciliated”) sexual cell. At one time supposed to be minute parasites in the semen, hence often called _spermatozooa_. =Sphinx fu-ci-form´is.= =Spon´gi-o-plasm= [Gr. _spongion_, little sponge; _plasso_, form.] =Steg-o-ceph´ala= [Gr. _stego_, cover; _kepale_, head.] Another name for Labyrinthodonts. =Sty-lo-nych´i-a.= =Su-pra-œ-soph-ag´e-al= [Lat. _supra_, above; œsophagus.] =Tar´si-us= [Gr. _tarsos_, any flat surface.] =Tax-o-nom´ic= [Gr. _taxis_, orderly arrangement; _nemein_, distribute.] Pertaining to systematic classification. =Tel-e-os´to-mi= [Gr. _teleos_, perfect; _stoma_, mouth.] A division of fishes with well-developed dentary and maxillary and membrane bones; includes all fishes except Elasmobranchii and lower forms. =Tel´e-osts= [Gr. _teleos_, perfect; _osteon_, bone.] A subdivision of Teleostomi that includes most fishes; decussation of optic nerves; non-contractile arterial bulb. =Ter´ti-a-ry= [Lat. _tertius_, third.] =Tet´ra-o cu´pi-do= [Lat. _tetrao_, pheasant; _Cupido_, the God of Love.] =Thal-am-en-ceph´a-lon= [Gr. _thalamos_, chamber; _enkephalos_, brain.] A fundamental segment of the brain. =Thal´a-mi= [Gr. _thalamos_, chamber.] The lateral boundaries of the thalamencephalon. =Thal´loph´y-ta= [Gr. _thallos_, young branch; _phyton_, plant.] =The-ro-mor´pha= [Gr. _ther_, beast; _morphe_, form.] =Tho-mi´sus cit´re-us.= =Ti-mor´.= =Top´knots.= Crests or tufts of feathers growing on the heads of birds. =Toxalbu´min= [Gr. _toxikon_, poison; _albumin_, < Lat. _albus_, white.] =Tri-as´sic= [Gr. _trias_, three.] =Tri´lo-bites= [Gr. _treis_, three; _lobos_, lobe.]