EUCAMPIA. 



[ '^46 ] 



EUGLENA. 



EUCAMPIA, Ehr. — A marine organism, 

 allied to the Desmidiaceae, among which it 

 is placed by Kiitzing. It forms articulated, 

 arcuate, fasciseform, microscopic fronds, com- 

 posed of hyaline, wedge-shaped joints, exca- 

 vated in the middle at both ends, with yel- 

 lowish granular contents. The joints shrink 

 in drying, and are destroyed by heat. The 

 bundles of E. zodiacus, the only species, are 

 1-96'" broad, the length of the joints being 

 U or 2 times the breadth (PL 41. fig. 10). 



BiBL. Ehrenb. Leb. Kreidethierch. Ahh. 

 Berl. Akad. 1839. p. 125; Kiitzing, Sp. 

 Algarum, p. 191, Kieselsch. Bacillar. pi. 21. 

 fig. 21. 



EUCERTYDIUM, Ehr.— A genus of Po- 

 lycistina. 



E. ampulla (PI. 31. fig. 25, front view; 

 fig. 26, under view). 



See POLYCISTINA. 



EUCHLANIDOTA, Ehr.— A family of 

 Rotatoria. 



Char. Rotatory organ multiple, or divided 

 into more than two lobes ; a carapace pre- 

 sent. 



The carapace forms either a testa or a 

 scutellum ; various appendages are present, 

 representing either straight bristles, curved 

 bristles, or hooks, minute horns, — so-called 

 respiratory tubes or antennae, — and in one 

 genus a frontal hood. 



The eleven genera are thus distinguished : 



Eyes absent ; foot forked { ^fplafJ!"' 



Eyes present. 

 Eye single (cervical). 

 Foot styliform. 



Carapace depressed Monostyla. 



,, prismatic Mastigocerca. 



Foot forked. 



Carapace open beneath Euchlanis. 



,, closed beneath 



Carapace with horns Salpina, 



,, without horns Dinocharis. 



Eyes two (frontal) . 



Foot styliform Monocerca. 



,, forked. 



Carapace compressed or prismatic Colurus. 

 Carapace depressed or cj'lindrical. 



Head without a hood Metopidia. 



,, with a hood Stephannps. 



Eyes four ; foot forked Fiquamellu. 



* Diplax, Gosse, does not differ from Lepadella, E . 



BiBL. Ehrenb. Infus. p. 455. 



EUCHLANIS, Ehr.— A genus of Rota- 

 toria, of the family Euchlanidota. 



Char. Eye single, cervical ; foot forked ; 

 carapace cleft or open on the ventral surface. 

 Aquatic. 



Ehrenberg describes six species, to which 

 Gosse adds three. 



E. triquetra (PI. 34. fig. 30 ; fig. 31, teeth). 



Carapace very large, with a dorsal crest ; 

 foot without setae; length 1-48". 



BiBL. Ehrenb. Infus. p. 461 ; Gosse, Ann. 

 Nat. Hist. 1851. viii. p. 200. 



EUDORINA, Ehr.— A supposed genus of 

 A^olvocineae (Confervoid Algae). Eudorina 

 elegans is described as a cluster of globular 

 green corpuscles, containing from fifteen to 

 thirty or fifty of them, enclosed in a hyaline 

 common envelope, about i -180" in diameter, 

 from which each protrudes a single cilium. 

 What we have found answering nearest to 

 this (PI. 3. fig. 14) has the zoospore-like 

 corpuscles provided with a pair of cilia. It 

 is said that Eudorina has the power of throw- 

 ing off its outer envelope or mantle, and 

 forming a new one. This strengthens our 

 suspicion that it is only a young form of 

 Volvox, in course of development from the 

 resting-spore, which must throw off its outer 

 firm coat in this way. Eudorina elegans is 

 most abundant in spring, in ponds with Vol- 

 vox, " Chlamidomonas," &c. See Volvox. 



BiBL. 'EAw. Infusionsth. ^.^2', Dujardin, 

 Infus. p. 317; Pritchard, Infusoria. 



EUGLENA, Ehr.— A genus of Infusoria, 

 of the family Astasiaea. 



Char. Unattached ; a red eye-speck ; a 

 tail-like process, and a single flagelliform 

 filament. 



Many species, or rather forms, are distin- 

 guished by Ehrenberg and Dujardin. They 

 are often present in vast numbers in pools, 

 &c., rendering them green or red, and form- 

 ing a brilliant pellicle upon the surface. 



In the free condition, the Euglence swdm 

 about in the water, not apparently by the 

 help of the flagelliform filament, which seems 

 to be often deficient, but by the contractile 

 action of the whole body, the changes of 

 form and movements of which may be 

 roughly compared to that of the common 

 leech when crawling sluggishly over the sur- 

 face of a glass. The Euglence present many 

 points of resemblance to the lower Algae, 

 especially Protococcus, like them varying in 

 colour from green to red, and, moreover, 

 passing through a resting stage, encysted in 

 a kind of cell- membrane, which is sometimes 

 gelatinous, transparent, and spherical, some- 

 times rather horny, and polygonal in form. 

 The encysted forms occur commonly aggre- 

 gated together into indefinite frond -like 

 masses, and the individuals multiply by divi- 

 sion into two, four, &c., in this quiescent 

 stage. The frond-like groups may be found 

 in autumn, and even under the ice in winter, 

 while the active forms abound most in spring 



