616 



SYSTEMATIC HISTORY OF THE INFUSORIA. 



FAMILY VI.— COLEPINA. 

 (XXIV. 284, 285). 



Loricated animalcules having the mouth and anus placed at the opposite 

 extremities of the body. The lorica is of the form of a small cask, composed 

 either of minute plates placed in a row, or of little rings between which 

 cilia are situated ; anteriorly it is truncated, smooth or toothed, and poste- 

 riorly terminated by three to five little points ; mouth cihated. The diges- 

 tive vacuoles in these creatiu^es are readily filled with coloured food, which is 

 ejected posteriorly. Complete transverse self-division has been observed. 

 A distinguishing character of the Ciliated Protozoa is their asymmetrical 

 figui^e ; but the genus Coleps is an exception to the general rule. 



In the act of fission a new formation of tissue appears to take place along 

 the future line of separation, thinner and softer in consistence than the 

 original covering. 



Genus COLEPS (XXIV. 284-286).— This being the only genus, its cha- 

 racteristics are identical with those of its family. 



CoLEPS Iw'tus {Cercaria hirta, M.) 

 (xxiv. 284-286).— Body white, oval, with 

 truncated ends; lorica apparently com- 

 posed of small polygonal plates, between 

 which the cilia are both transversely 

 and longitudinally aiTanged. Anteriorly 

 there are nineteen pointed processes, and 

 posteriorly three. Movements very brisk ; 

 so that it is difficult to examine the lorica 

 while the animal is living ; but when it 

 is dried, or pressed between glasses, the 

 complex structure of the former is 

 rendered visible. Amongst Confervse. 

 1-570" to 1-430." 



Although described by Ehrenberg as 

 colomiess or white, this is no specific 

 character ; for it may frequently be co- 

 loured green by chlorophyll, or tinted 

 with intermediate shades between yel- 

 low, green, and brown, according to the 

 food taken and its changes by digestion. 



C. viridis. — Green, oval, and ciliated; 

 lorica terminating in three points. 

 Amongst Confervc^. 1-960" to 1-570". 



Except in the matter of colour, no 

 distinction from the preceding is noted ; 

 its specific independence may therefore 

 be fairly questioned. 



C. elongatus. — Cylindrical, elongated; 

 lorica white, and terminating in three 

 points ; self-division transverse. 1-570" 

 to 1-430". 



Between this form and C. hirtus Perty 

 has seen every intermediate figure, and 

 therefore regards it as a mere variety, 

 and not a species. The colom', it hardly 

 needs be stated, is in no way character- 

 istic. 



C. amphacanthus. — Ovate, shorter. Lo- 

 rica, unlike that of the other species, com- 

 posed of rings ; the anterior part crowned 

 with unequal teeth, the posterior having 

 three strong spines. Found in Spiro- 

 stomum vij'ens, 1-280". 



C. incurvus. — Oblong, nearly cylin- 

 drical, and slightly curved; lorica ter- 

 minating in five points. Amongst Con- 

 ferv£e. 1-430". 



C. inermis (Perty). — Lorica costate, 

 not granular ; no spinous points at pos- 

 terior end, or very feeble ones. Greeu 

 corpuscles occur internally. The dis- 

 tinctness of the ribs varies, as weU as the 

 length and thickness of the body. Mo- 

 tions like those of C. hirtus. 1-600". 

 Fresh water. 



FAMILY VII.— TRACHELINA. 



(XXIV., XXVIII., XXIX.) 



This extensive family includes those animalcules which have two distinct 

 alimentary orifices — the recei\ing one lateral, the discharging one terminal. 

 They have no lorica ; but all the genera, except Phialina, are covered with 

 vibrating ciha, generally disposed in longitudinal rows, those near the 

 mouth being the longest. Trachdius has no neck ; but the frontal portion of 

 the body is prolonged, in the form of a long trunk-like hp ; in Lo.vodes ^n^ 

 ChUodon it is like a hatchet-shaped broad lip. In Glaucoma there is a 



