TILILAMOPORA. 



[ 7G4 ] 



TIIECAMOKIDINA. 



Instead of the biserial form, frequently 

 tlie shell begins with a triserial arrange- 

 ment of chambers ( l^erneuilina, with con- 

 tracted aperture ; Candeina ?, with perforate 

 septa). The Verueuiliue commencement is 

 often succeeded by the usual two alternating 

 rows {Gaudri/ina, G. pupoidea, PL 23.fig.48), 

 or by a linear growth with terminal aperture 

 ( Tritadi(i). The triserial varieties are some- 

 times twisted. If T^idvtdiiia takes on the 

 linear growth, we have Venilina. 



The early chambers of Textidaria and its 

 modiiications are not uufrequeutly coiled 

 (Spiroplecta). Textidaria (»S}j.) annectens 

 (Pi. 2-j. fig. 52), from the Gault, commenced 

 spiralh", proceeded biserially, and ended 

 with uniserial chambers. 



Large Textiilarice are rarely porous and 

 translucent; they usually become sandy 

 {^Pleeuniiun). 



Common in all seas, and fossil in all 

 formations from the Silurian upwards. 



BiBL. D'Orbigay, For. Fuss. Vien. 24o; 

 Williamson, For. 75 ; Morris, Cat. Br. Foss, 

 4f3; Bi-oan, Index Pal. art. Text.; Ehren- 

 berg, Mikrog. ; Schultze, Org. Polyth. 62 ; 

 Carpenter, For. 189; Parker and Jones, 

 Ann. N. H. 3. xi. 91 ; 4. ix. 298, x. 189, 

 196, 259; Brady, Carh. For., Pal. Soc. 

 1876, 130. 



THALAMOP'ORA, Eeuss. — A large, 

 subcylindric, zoophytoid Foraminifer, com- 

 posed of superimposed chambers, with laby- 

 rinthic and perforated walls, arranged around, 

 and opening into, a central vertical cavity. 

 Tludamopora exhibits characters of alliance 

 with Polgtrema, Carpcnteria, Tinoporus, 

 Ci/mbalopora, and, through the last, with 

 Planorhulina and others of the Rotalina. It 

 is among the Perforata what Ductylopura is 

 among the Imperforata. (Reuss, Geinitz's 

 Elhthak/ehmie, 1872, 139.) 



THALASSICOL'LIUA, Huxley. — A 

 family of Radiolarian Rhizopoda. 



Char. Composed of structureless cysts, 

 single or aggregate, containing cellular ele- 

 ments and sarcode, giving ofi" radiate pseu- 

 dopodia, which sometimes run into each 

 uther and form a network. Nucleus present, 

 l)ut no contracting vesicle. Numerous yel- 

 low cells occur scattered through them ; 

 and occasionally a few may be seen suspended 

 within the external gelatinous structure. 



The whole organism is permeated by spicula, 

 or sustained by a fenestrated shell. The 

 most common genera are SphcBrozoum, Col- 

 losphcera, and Thalassivolla. They are ma- 

 rine, in tropical and subtropical seas. 



BiBL. Huxley, Ann. N. H. 2. viii. 1851, 

 489; Qu. Mic. Jn. iv. 1856, 72; Miiller, 

 Thalass. ; Plaeckel, Radiolarien, 1862 ; Wal- 

 lich, Ann. N. II. 1869, iii. 97. 



TllALES'TRlS, Claus. — A genus of 

 Copepodous Entomostraca. Ten species, 

 marine. (Bradv, Copep., Pag Soc. ii. 120.) 



THAMNO'LIA, Ach.— A genus of Cla- 

 dodei (Lichenaceous Lichens). 



T. vennicularis ; on mossy earth ; rare. 

 (Leighton, Lich. Fl. 74.) 



THAMNOM'YCES, Ehr.— A genus of 

 Sphagriacei (Ascomycetous Fungi). It has 

 distinct asci and sporidia. (Berk. Br. Flor. 

 ii. pt. 2. 284; Fries, Su7n. Veq. 382.) 



THAUMAN'TIAS, Esehscholtz. — A 

 genus of Campanulariidfe. 



Char. Stem simple (or branched ? ), rooted 

 by a thread-like stolon ; cells campanulate ; 

 polypes with a funnel-shaped proboscis; re- 

 production by free medusiform buds. 



T. inconspicua, Forbes. Common off the 

 Hebrides. (Hincks, Hi/d. Zooph. 178.) 



THAUMATONK'MA, Grev.— A genus 

 of T»iatoniacea3. (Grev. Mic. Tr. 1863, 76.) 



THECA. — A term used very loosely in 

 the descriptions of Cryptogamic plants. In 

 the case of the Lichens and Fungi it is syn- 

 onymous with Ascus, a sac in which free 

 spores are developed ; these are called theca- 

 spores or ascospores, in contrast with basi- 

 DiosPOEES or stylospores. In the higlier 

 Cryptogamia, as Ferns, &c., it is used in the 

 sense of sporangium. 



THECAMONADI'NA, Divj.— A family 

 of Infusoria (=Cryptomonadina and some 

 Astasitea, E.). 



Char. Usually coloured ; covered witli a 

 non-contractile tegument, which is either 

 hard and brittle, or membranous ; locomotive 

 organs one or more fiagelliform filaments. 



Many are Algae, or their spores. They 

 are minute, usually green, but some are red ; 

 and they often colour stagnant water from 

 existing in vast numbers. They are mostly 

 recognizable by their rigidity ar.d the uui- 

 formity of their motion. 



Dujardin subdivided them thus : — 



' A single 

 llnf^clliform 

 ulameiit. 



Body ovoid orj Tegument hard and brittle 1. Trachelomonas. 



globular ( TegunK'nt membranous 2. Cri/pfo^iioiia/f. 



Body depressed or ( with a tail-like urolongation 3. Phttcus (Ktigleini pt., E.) 



folia'ceoiis 'l without a prolongation 4. CrumeinUti. 



rp (Two similar filaments 5. Diselmis (Cklamid.omonas, E.). 



fii *^°. -One flogelliform filament, and ( Body jirismatic or boat-shaped 6. Ploeotia. 



niaments. / o„,, traUing retractile filament) Bodv ovoid or pip-shaiied 7. Anisonema. 



, Several filaments Body prolonged into a point in front 8. Ojyrrhis. 



