UVELLA. 



Fig. 790. 



[ 799 ] 



VALLISNEEIA. 



Muscular elements from a uterus at five months' ges- 

 tation, a, formative cells ; b, young, c, fully developed 

 muscular fibres. Magnified &30 diameters. 



moving by means of two flagelliform fila- 

 ments, and aggregated into spherical revol- 

 ving clusters. 



U. virescens (PI. 32. fig. 18). Bodies 

 ovate, rounded at each end, with two lateral 

 bright green bands. Diameter of clusters 

 1-288", length of bodies 1-2016" ; fresh- 

 water. 



The life-cycle of a cercomonad. One of 

 the Uvelke has been described by Dallinger 

 and Drysdale. When mature it multiplies 

 by fission for a period extending over from 

 two to eight days. It then becomes pecu- 

 liarly amoeboid ; two individuals coalesce, 

 slowly increase in size, and become a slightly 

 distended cyst. The cyst bursts, and incal- 

 culable hosts of excessively minute sporules 

 are poured out, as if in a viscid fluid and 

 densely packed; these are scattered, and 

 slowly enlarging, acquire flagella. Thev be- 

 come active, attain rapidly the parent form, 

 and once more increase by fission. 



BIBL. Dallinger and Drysdale, Mn. Mic. 

 Jn. 187:;; Ehr. Inf. 19; Duj. Inf. 300; 

 Kent, Inf. 400. 



< UVIGERrNA D'Orb. A genus of hya- 

 line Foramiuifera, near Polymorphina. Shell 

 made up of tliree series of inflated chambers, 

 alternating irregularly on an elongate spire, 

 often ribbed ; orifice central, round, tubular, 

 and lipped. The triserial alternation passes 

 sometimes into a biserial and even a uni- 

 serial growth (Sagrina, restricted). Uviye- 

 rina is world- wide in its distribution, and 

 goes back to the Middle Tertiary Period. 

 U. pygmaa (PI. 23. fig. 8). 

 BIBL. D'Orbigny, Ann. Sc. Nat. vii. 269 ; 

 Carpenter, For. 1C9 ; Parker & Jones, Phil. 

 Tr. civ. 363. 



V. 



VAGINIC'OLA, Lamarck. A genus 

 of Peritrichous Infusoria, fam. Vorticellina. 



Char. Bodies as in Vorticella, single or 

 in pairs, in a membranous urceolate sessile 

 sheath. 



V. crystallina (PI. 32. fig. 19) = Cothurnia 

 crystalline Sheath crystalline, urceolate, 

 straight, internal granules erreen ; length 

 1-216". 



Several species, salt and freshwater. 



BIBL. Ehr. Inf. 295 ; Clap. & Lach. Inf. 

 126. 



VAGINULI'NA, D'Orb. A Stichoste- 

 gian subgenus of Nodosarina, with oblique 

 chambers. 



V. ladenemis, D'Orb. (PL 23. fig. 35). 



BIBL. Williamson, Foram. 21 (Dentalma) ; 

 Jones, Parker, and Brady, Monogr. For. 

 Crag, 63. 



VALKE'RIA, Flem. A genus of In- 

 fundibulate Ctenostoniatous Polyzoa, of the 

 family Vesiculariidse. 



Char. Variously branched; cells oval, 

 irregularly clustered; eight tentacles, but 

 no gizzard. 



V. cuscuta. Stem with subverticillate 

 branches ; cells in clusters or opposite pairs ; 

 on marine Algse, shells &c. 



V. uva. Stem creeping, irregularly 

 branched ; cells scattered. 



V.ptutxdota. Dichotomous or alternately 

 branched ; cells clustered, unilateral. 



V. tremella. Cells very small and slender. 



BIBL. Johnst. Br. Zooph. 373; Gosse, 

 Mar. Zool. ii. 20; Hincks, Polyz. 551. 



VALLISNE'RIA, Mich. An aquatic 

 genus of Angiosperrnous Flowering Plants, 

 belonging to the family Hydrocharidacese. 

 V. spiral-is, a native of the South of Europe, 

 occurring wild also in North America, India, 

 &c., is commonly grown in jars for the sake 



