624 



SYSTEMATIC HISTORY OF THE INFUSORIA. 



Genus GLAUCOMA (XXIV. 300-302 ; XXVIII. 4-7).— Body oval, com- 

 pressed, covered with cilia ; mouth provided with a tremulous flap, but no 

 teeth. Ehrenberg described the reception and discharge of food, and the 

 presence of digestive vacuoles, and therefore saw, in these, indications of the 

 existence of an alimentary canal. The large mouth, with its vibratory valves, 

 is situated on the inferior side, in advance of the middle. The anus is situated 

 on the ventral surface, near the posterior extremity, or at the extremity 

 itself. The internal organs are a large ovate gland, a star-like contractile 

 sac, and granules. Self- division transverse or longitudinal. 



Glaucoma is comprised by Dujardin among his Paramecina. Perty con- 

 structs a family out of this genus, along with CinetochUum (vide Cyclidium, 

 p. 572), Avhich he designates CinetochiHna, and characterizes as animalcules 

 having a mouth on the upper side, surmounted by a vibrating valve (Hke a 

 tremulous eyelid). Cilia disposed in longitudinal rows. It will be noticed 

 that the mouth is described to be on the upper side instead of the under, as 

 stated by Ehrenberg, with whom we agree. 



The anus is on the ventral surface, near the posterior extremity. Lachmann 

 describes two flaps to the mouth, but Perty says the second is simply an 

 expansion of the margin of the mouth. 



Glaucoma scintillans ( CyclidiumBulla, 

 M.) (xxviii. 4-7). — Elliptical or ovate, 

 colourless, slightly depressed ; vacuoles 

 large. The vibrating flap appears to be 

 semi-oval or reniform and smooth, and 

 to have a stiff" margin. The cilia are 

 seen by employing colour or by pressing 



or drying the animalcules (xxiv. 300- 

 302). In natural and artificial infusions. 

 1-280". 



G. viriclis (Duj.). — Green, oval, short; 

 mouth large, situated nearer the centre 

 than to the anterior margin. 1-860" to 

 1-520". In rain-water butts. 



Genus CHILODON (XXIV. 303-309 ; XXIX. 48-59).— Body irregularly 

 oval, flattened, regularly ciliated : frontal region produced in the form of a 

 broad membranous lip, on one side, resembling a beak ; the mouth, situated 

 at its base, and therefore lateral, is furnished with a tubular fascicle of teeth. 

 A round nucleus, one or more contractile vesicles, and transverse and longi- 

 tudinal self-division have been observed. 



This genus along with Nassvia, Prorodon, and two newly-instituted genera, 

 CycJogramma and Hahrodon, are grouped together in the system of Perty, 

 as a family styled '^ Decteria,''^ which is thus characterized : — ^' Mouth beset 

 with a circlet of fine bristles. In the first three genera the mouth is lateral ; 

 in the remaining two, anterior." 



Stein makes Chihdon distinct from Nassula, by its body being compressed, 

 having a distinct upper and under surface, and a lip-like process above the 

 mouth. 



Chilodon Cucullulus (Kolpoda Cucidlus, 

 M.) (xxiv. 303-307; xxix. 48-59).— 

 Body depressed, oblong or ovate, rounded 

 at the ends ; frontal region advancing on 

 the right side. [Ehrenberg states he has 

 often seen the straight alimentary canal, 

 with its gi-ape-like cells, filled with 

 large Naviculce.] Contractile vesicles 

 from two to three ; nucleus large, oval 

 near the centre. The circlet of teeth 

 was stated by Ehrenberg to consist of 

 little hard wand-lilfe bodies, which the 

 creature could separate so as to admit 

 into its mouth large living bodies, and 



afterwards contract or close upon them 

 (xxiv. 308, 309). The anus is at one 

 side of the posterior extremity. In 

 swimming, or creepmg upon the surface 

 of ConfervcT, the mouth is timied under 

 or below. Its motion is gliding ; and it 

 does not revolve in swimming. When 

 the water is coloured, the cilia may be 

 easily perceived, and their disposition 

 when it is dried up. (Figs. 305 and 306 

 exhibit longitudinal, and 307 transverse 

 self-division.) In fresh and salt water. 

 1-1150" to 1-140". 

 This species has received a close in- 



