648 DESCRIPTION OF IRotatoriu. 



with four eyes ; and fig. 429 an animalcule with body contracted, 

 but jaws extended. Found amongst Oscillatoria. Length 1-1 40th. 

 Theoutjs uncijiatus. — Toes long, a frontal uncinus or hook present. 

 Six visual points have been seen by Ehi'enberg. Found amongst 

 Oscillatoria. Length 1 -240th. 



The two next genera mentioned are from Mr. Gosse, who, 

 however, adduces the latter as a doubtful member of the present 

 family. 



Genus Asplanchna (Gosse.) (Annals Nat. Hist., vol. 6, July, 

 1850.) — Eotatorial hydatina;a destitute of foot, intestine, and anus ; 

 but possessing eyes (oceilli) and jaws; sexes disjoined. 



This new genus, instituted by Mr. Gosse, embraces the Eotatorial 

 animal which Mr. Bright well introduced to notice as "a supposed 

 new species of Notommata-y — (Fauna Infusoria, Norfolk 1849), and 

 in which he first detected the existence of male animals, distinct in 

 organization and character from the female. It was soon perceived 

 that the new forms represented by Mr. Brightwell, could not belong 

 to the genus Notommata of Ehrenberg ; and the discovery of other 

 similar beings has led to the creation of this genus Ai^planchna. 



A. BriglitwelUi. — Jaws (mandibles) one-toothed ; eye single ; 

 stomach oval, longitudinal ; vesicle lobed, larger ; tremulous cor- 

 puscles (gills, Ehr.) afiixed to a long filament ; ovaiy two- homed. 

 Length about l-24th. (P. 15, f. 65, 66.) Males with jaws, pharynx 

 and stomach absent ; body truncate. Length about 1 -40th. Found 

 at Norwich, Leamington, Hampstead Heath, &cc." 



Mr. Brightwell' s account is embraced in the following extracts : — 



"It (the female) is furnished with an ovisac, in which the young 

 may be clearly detected, and from which they are expelled through 

 the sides of the animal. Some of the young appear to diff'er in 

 form from the others, and there appear to be two kinds of ova ; 

 one, and that by far the greater number, transparent, and hatched 

 in the body of the parent ; the other, more opaque, perhaps re- 

 maining unhatched, or deposited till vilified under favourable 

 circumstances, in some ensuing season. Should this, on further 



