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body or in the oral region ; \u201coverproduction\u201d dur- ing stomatogenesis appears to be a source of some of these supernumeraries (e.g. in the parakinetal stomatogenesis of Tetrahymena ); in some cases, they may be erratic kinetosomes and/or parts of an anlage and/or parts of a vestige ; might also include cases of intercalated kineties , whole or partial, which involve a line or file of several or even many additional somatic kinetosomes. Supraepiplasmic Microtubules : microtubules, single or in ribbons, lying above the epiplasm and coursing along parallel to the outer surface of the cell. Suture Lines : simply folds or creases in the pel- licle ; preferably associated with the important concept of the secant system , the converging of kineties from different areas of the surface of the ciliate onto suture lines forming a pattern con- sistent within a given taxonomic group; see also Postoral Suture and Preoral Suture . Swarmer : dispersive form in the life cycle of a number of ciliates; see Larval Form . Symbiont : so-called dependent member or partner, except in cases of mutualism , of a pair of organisms exhibiting symbiosis , the other being the host ; see Commensalism , Mutualism , and Parasitism . Symbiosis : the living together, more or less intimately and contiguously, of two organisms, the host and the symbiont ; see Commensalism , Mutualism , and Parasitism. Symbiotic (adj.): see Symbiosis . Symmetrogenic Fission : type of fission , generally longitudinal, of a parental form in such a manner that the two filial products are, in effect, mirror images of one another with respect to principal structures; typical of non-ciliate protozoa; compare to Homothetogenic Fission (Fig. 2.11Ab). Symphoriont : symbiont exhibiting a kind of com- mensalism in which the host , usually via its 56 2. Glossary of Terms and Concepts Useful in Ciliate Systematics integument, appears to serve solely as a convenient substratum for attachment of the typically stalked sessile ciliate; not always clearly distinguishable from other degrees of intimacy between hosts and their associated ectocommensals, but it represents a convenient term with reference to many peritrich and suctorian species; not generally used, by con- vention, for parasitic ciliates exhibiting a phoront stage, which, however, can really be functionally very similar; see Phoront . Symplesiomorphic : shared ancestral homologous character ; compare with Synapomorphic . Synapomorphic : shared derived homologous character or shared apomorphies ; used to unam- biguously define a clade or monophyletic group. Synciliary Ciliature : see Syncilium . Syncilium (pl. Syncilia ): a group of closely packed somatic cilia forming a special tuft exhibiting considerable internal coherence and arising from a packet of kinetosomes that are interconnected at their proximal ends with other syncilia; character- istic of entodiniomorphid vestibuliferans , syncilia were formerly called membranelles , with recogni- tion of adoral and dorsal zones ; they also occur as part of the caudalia present at the posterior end of the body of certain cycloposthiid entodiniomor- phids ; see Polybrachykinety (Syn, Fig. 2.5Af). Syndesmogamy : a conjugation found only in apostomes during which two trophonts encyst together and undergo preconjugation division by linear palintomy , after which the filial products fuse and conjugate; also called zygopalintomy. Syngamy : fusion of the gametic nuclei during con- jugation ; also called fertilization or karyogamy. Syngen : complex of two or more sexually com- patible mating types (e.g., in Paramecium or Tetrahymena ), formerly known as \u201c varieties \u201d; long recognized as reproductively isolated biological units, hence biological species ; see Variety . Synhymenium : single apparent \u201cmembrane\u201d resulting from an uninterrupted joining of the pavés of the frange of some nassophoreans . Synkaryon : nucleus formed by fusion of two hap- loid gametic nuclei or pronuclei in the sexual phe- nomena of conjugation or autogamy ; its division products differentiate into the new diploid micro- nuclei and the typically polyploid macronuclei ; see Zygotic Nucleus . Synonym : one or two or more names applied to the same organism or taxon; the oldest or earli- est published is the senior synonym, which name usually must prevail; the later or younger of two is the junior synonym; an objective synonym is one based on study of the same material as the original describer, whereas a subjective synonym is based on material that is different but alleged to represent the original organism or taxon; see Homonym , Rule of Priority . Système Sécant : see Secant System . Systole : see Contractile Vacuole . T Tactile Cilium (pl. Cilia ): see Sensory Bristle and Thigmotactic Cilia . Tail : generalized term, variously used in non- specific ways; a caudal appendage, ranging from specialized cilia or mucous filaments to narrow and lengthy extensions of the body proper. Tangential Fibers : see preferred term, Transverse Microtubules . Tastcilie (pl. Tastcilien ): see Sensory Bristle(s) . Tectin Granules : small, subpellicularly located bodies involved in secretion of a substance, prob- ably mucopolysaccharide in nature, used to con- struct the lorica in a number of ciliates, especially among the sessiline peritrichs . Teeth : nonspecific term; but also, perhaps unwisely, used to describe the nematodesmal capitula char- acteristic of some dysteriid cyrtophorines ; see Capitulum . Tela Corticalis : synonym of lamina corticalis . Telokinetal : type of stomatogenesis in which forma- tion of the new oral structures occurs by direct involve- ment either of kinetosomes at the anterior extremities of all or some of the encircling somatic kineties or of kinetosomes comprising the short kinetofragments available in the vicinity; see Cryptotelokinetal, Holotelokinetal, Intertelokinetal, Merotelokinetal, Monotelokinetal , and Pleurotelokinetal (Fig. 2.11Da, 2.11Db). Glossary 57 Teloparakinetal : parakinetal stomatogenesis in which the oral anlage originates by proliferation of kinetosomes at the anterior ends of postoral kinetofragments and at the \u201cbroken ends\u201d of bipo- lar somatic kineties ; found in ophryoglenids . Telotroch : migratory free-swimming larval form , especially in the life cycle of sessiline peritrichs ; trophonts of mobiline peritrichs are sometimes thought of as permanent telotrochs exhibiting neo- teny (Fig. 2.11B). TEM : transmission electron microscopy. Temporary Conjugation : fusion with subse- quent separation of the members of the conjugat- ing pair; the mode of conjugation shown by most ciliates except peritrichs , chonotrichs , and some suctorians , which show total conjugation ; see Conjugation . Tentacle : tubular extension of or projection from the surface, of several different and probably non- homologous kinds, typically supported by micro- tubular ribbons : (1) suctorial tentacle , the (only) ingestatory apparatus in suctorians; (2) prehensile tentacle , a non-ingestatory structure present in some suctorians , solely for prey capture; (3) the short, non-extensible, apical sucking tube of rhyn- chodids and grossglockneriid colpodeans ; (4) the non-suctorial but highly extensible and retractable prey-capturing organelle of such unusual hapto- rians as Actinobolina , composed of microtubular arrays often enclosing a prominent toxicyst and found in abundance, over the surface of the body; and (5) scattered other projections, lobes, or palps, and the like, which are or have been occasionally referred to by the term \u201ctentacle\u201d, but properly excluding any proboscis (Fig. 2.10). Tentaculoid : small finger-like extensions of the cytoplasm,