EUPLOTES. 



[ 248 ] 



EUROTIUM. 



EUPLOTES, Ehr. {PMsconia, Duj. for 

 the most part). — A genus of Infusoria, of 

 the family Euplota, E. 



Char. Furnished with cihaj styles, and 

 hooks ; teeth absent. 



The species are very numerous. 



E. patella, E. {Ploesconiapat., D.) (PI. 24. 

 fig. 5; a, under view; b, side view). Cara- 

 pace a testa, oval or suborbicular, slightly 

 truncated in front, margins extending be- 

 yond the depressed body ; dorsum raised or 

 bossed with fine radiating striae ; cilia form- 

 ing a curvilinear series. Aquatic; length 

 1-288 to 1-216". 



E. cimex, E. {Coccudina cimex, D.). 



E. charon, E. {Ploesconia charon, D.). 



E. vannus, E. {PL vannus, D.) (PI. 24. 



E. monostyla, E. {Ervilia legumen, D.) 

 (PL 23. fig. 52). 



BiBL. Ehrenb. Infus. p. 377; Duj. Infus. 

 p. 435; Stein, Infus. p. 158. 



EUPODISCUS, Ehr.— A genus of Diato- 

 maceae. 



Char. Erustules single, disk-shaped, cir- 

 cular, without internal septa; valves fur- 

 nished with tubular or spiniform processes. 

 Marine and fossil. 



The processes are so easily broken off, 

 that the apertures corresponding to the 

 points of attachment are generally alone 

 seen. The valves appear either distinctly 

 areolar, the depressions being large ; granu- 

 lar, from their being minute; or striated. 



Two groups are recognizable : 



a. Eupodiscus proper. Valves areolar. 

 E. argus (PI. 12. fig. 30; a, side view; 



b, front view). Valves slightly convex ; 

 processes three ; diameter 1-156". 



E. sculptus, Sm. (PI. 12. fig. 31). Valves 

 striated, central striae forming a quatrefoil ; 

 processes two; diameter 1-770 to 1-400". 



b. Aulacodiscus, E. Valves granular ; 

 processes very short, their bases connected 

 with the centre of the valve by a furrow. 



KPdersu}''^'^'^^^^'^-''^^^''- 



BiBL. Ehrenb. Abh. d. Berl. AJcad. 1839, 

 id. Bericht. 1844. p. 73, 1845. p. 361; Smith, 

 Brit. Diat. i. p. 24 ; Kiitzing, Sp. Alg. p. 

 134. 



EUPOTIUM.— A geaus of Marattiaceous 

 Ferns. Exotic. 



EUROTIUM, Lk.— A genus of Mucorini 

 (Hyphomycetous Fungi), on the distinct 

 nature of which great doubt is thrown by 

 the recent observations of De Bary. E. her- 

 bariorum of authors is a mildew, common 



upon preserved fruits, forming a whitish or 

 yellov»' crust, composed of interwoven myce- 

 lium filaments, which are delicate when 

 young, but become thickened and often co- 

 loured with age. Upon these are produced 

 globular conceptacles or peridia, from 1-15 

 to 1-20'" in diameter, composed of a dis- 

 tinctly cellular membrane, enclosing little 

 sacs or asci containing several minute spores. 

 According to De Bary, these conceptacles 

 are produced upon the mycelium of Asper- 

 gillus, under certain unknown conditions, 

 and the ordinary fructification of Aspergillus 

 is only a basidiosporous form of the same 

 plant which produces an ascophorous form 

 in the Eurotium fruit. He states that he 

 not only found them growing upon the con- 

 tinuations of the same branched mycelium 

 filament, but that he has raised Aspergillus, 

 which fruited, from the spores both of As- 

 pergillus fruits and of Eurotium. He was 

 unable to obtain Eurotium from Aspergillus 

 spores. The connexion between these forms 

 is regarded by him as analogous to that be- 

 tween Oidium and Erysiphe, but the con- 

 ceptacles of Eurotium do not originate in 

 the same way as those of Erysiphe from the 

 mycelium filaments. According to his ela- 

 borate account, the production of the fruit 

 of Eurotium takes place in a most remark- 

 able manner. The ends of the branches of 

 the mycelium coil up like a cork-screw, be- 

 coming more closely approximated, until at 

 length they come into contact, and form a 

 cylindrical or conical mass, marked exter- 

 nally by the spiral lines of conjunction of 

 the turns of the filament. The mode of 

 transformation into the cellular conceptacle 

 could not be traced in its minute details, 

 but all possible stages were found upon the 

 same mycelium, between the loose spiral 

 coil and the globular sac, composed of a 

 distinctly cellular membrane, in the cavity of 

 which became developed the asci or parent- 

 cells of the spores. The ripe spores often 

 exhibit a curious form, hke little C3dinders 

 with a concavo-convex cap applied over each 

 end ; these appear to be the two halves of 

 the dehiscent outer membrane (exospore), 

 for in the germination of perfectly globular 

 forms the mycelium filaments break through 

 the outer tough coat, like a pollen-tube from 

 the inner coat of a j^ollen-grain. The spores 

 are about 1-350"' in diameter, and of a light 

 yellow colour in mass. The dimensions, &c. 

 of Eurotium, like those of Aspergillus, seem 

 to vary with the external conditions. 



The above curious phaenomena deserve 



