636 



SYSTEMATIC HISTOEY OF THE IN-FUSOEIA. 



ment sudden, frequently oscillating-. 

 1-430." 



P. aureoJum. — Transparent, peacli- 

 coloured or golden yellow ; plaits strong. 

 Movements sluggish. 1-430". 



P. leucas=Bursana leucas? (Elir.). — 

 On one side a liorn-like process, and on 

 the other a pair of eminences project. 

 Movements slow. 



P. stomioptycha (E.). — Oblong, ob- 

 tusely ovate, tm-gid ; oral aperture large. 



reniform, cilia long; body marked by 

 circular folds ; lip with peculiar appen- 

 dages ; vesicles two, stellate ; nucleus 

 elongated, cylindrical. Mouth occupies 

 the anterior third of the body, sur- 

 mounted, however, by its obtuse frontal 

 end; cilia dense, in longitudinal rows; 

 vacuoles numerous ; colour yellowish- 

 white ; nucleus above one-third of the 

 entire length, which varies from 1-24'" 

 to 1-15'". 



Genus AMPHILEPTUS. — Tongue-like process and eye-speck absent ; but 

 the body is furnished with a proboscis and tail, and is elongated fusiform or 

 lanceolate. Cilia numerous, disposed in longitudinal series : in one species 

 cilia are not visible ; but in this the flexible attenuated extremities of the body 

 serve their office as locomotive organs. In some the tail (foot) and proboscis 

 (brow) are rudimentary. Numerous vacuoles filled "with food may be fre- 

 quently seen ; the mouth and anus are usually distinguishable. A. marga- 

 ritifer has a pale rose-red fluid. A contractile vesicle and a nucleus are 

 found ; the latter is globular or moniliform. Self-di^ision occurs both 

 transversely and longitudinally, or transversely only. 



Speaking of Ehrenberg's distribution of this genus, Dujardin remarks — 

 <' This author, whilst assuming the presence of proboscis and tail (as a cha- 

 racteristic), yet refers to the genus animalcules without tail, and dilated and 

 rounded posteriorly ; and on the other hand, whilst intent on seeking a 

 distinctive character for his different families in the position of the anus, 

 which he attributes to all his Enterodelous Infusoria, he has left in his genus 

 Trachel'ms several species which to us appear to belong to Amphileptus, and 

 has himself several times transferred some species from one genus to the 

 other." The Am-pliUeptus Anser is taken by Dujardin as the type of a genus 

 termed Dlleptus, and A. Meleayr'is of one termed Loxoj>7iyJhim. Amphileptus is 

 the name of a genus comprehended by Perty in his family Trachelina, which 

 appears generally equivalent to that bearing the same name in Ehrenberg's 

 system ; but it contains besides, TracheJhis vorax. Cohn remaks that it is 

 imperfectly distinguished by Ehrenberg from Tracliel'ms. 



The Amphilepti are commonly found, in the Hmpid water of marshes or 

 brooks, among aquatic plants. 



Amphileptus Anser ( Vibrio Anser et 

 Cygnus, M. = Dileptus, D.) (xxiv. 312, 

 3i3). — Turgid, spindle-shaped ; pro- 

 boscis obtuse, same leng-th as body ; tail 

 short and acute. The neck-like pro- 

 boscis is in reality a brow or upper lip, 

 the mouth being at the base. Ehrenberg 

 thinks he has seen the anal opening upon 

 the dorsal surface, near the tail. The 

 motion of the body is slow, but that of 

 the proboscis more active. It is very 

 often coloured green with chlorophyll, 

 received as food. Amongst dead sedge- 

 leaves, «&c. 1-120". 



A. maryaritifer. — White, slender, 

 spindle-shaped ; proboscis acute, equals 

 the length of the body ; tail short. The 

 most striking features are the swollen 

 margin of the mouth, and nccldace-like 



series of vesicles disposed along the 

 body. It feeds upon green Monads, like 

 the preceding species in Ehrenberg's 

 figm-es. Cilia are not sho\\Ti. Amongst 

 colonies of Vorticcllce, &c. 1-72". This 

 species is the counterpart of the pre- 

 ceding; and the distinction found by 

 Ehrenberg iu the necklace-like vesicles 

 has no value as such, since these vary 

 both in number and position according 

 to the abundance of food and other 

 external circumstances. 



A. moniliyer. — Turgid, ample, white; 

 proboscis and tail short. It has a 

 necklace-like collection of rose-coloiued 

 vesicles. Amongst duck-weed. 1-96" 

 to 1-72". 



A. riri(Us. — Turgid, spindle-shaped, 

 green; proboscis and tail short and 



