662 



SYSTEMATIC HISTORY OF THE rNTUSORIA. 



upper thick end (in the large species) two semiglobular glands are seen ; at 

 certain periods from one to three large ova are formed posteriorly, but the 

 ovarium in which they are developed has not been directly observed ; male 

 reproductive organs unknown. They are sluggish in their movements, except 

 in creeping; they rarely swim. (See Part I. p. 380 et seq.) 



berg has seen only one large o\Tim ; he 



Cils:tonotus maximiis (xxxi. 29, 30). 

 — Elongated, slightly constricted ante- 

 riorly, tui'gid and obtusely three-lobed ; 

 hairs upon the back short and equal. 

 From his latest observ-ations, Elirenberg 

 states the mouth to possess teeth, of 

 which he has counted more than eight ; 

 he once saw the exclusion of ova imme- 

 diately over the foot-like tail. It creeps 

 but slowly. 1-216" to 1-120". (See 

 p. 381.) 



C. Larus (Trichoda Acarus, Anas et 

 LaruSy M.). — Elongated, slightly con- 

 stricted anteriorly, where it is turgid and 

 obtusely triangular; the posterior han 

 on the dorsal surface is long-est. Ehren- 



states that the bodies of those bearing 

 ova were thick posteriori}^, though, under 

 other circumstances, the head is broadest. 

 It appears to have eight teeth. The dor- 

 sal hairs, which are arranged in longi- 

 tudinal rows, destroy the transparency 

 of the body. xxv. 357 is a dorsal, and 

 358 a side view. Ova one-third the 

 length of the body. In muddy water. 

 1-720". 



C. hrevis. — Ovato-oblong, slightly con- 

 stricted near the turgid front; dorsal 

 hairs few, the posterior longest ; ova 

 small. 1-340". 



As before stated, Dujardin places this genus, together with Ichthydium, 

 among the Infusoria (Polygastrica, Elir.), but in a subclass of them, called 

 symmetrical, along with Coleps and a doubtful genus named Planariola. 

 These genera are distinguished by him from all other Infusoria in baring a 

 symmetrical figure. 



One species of Chcetonotus described by Dujardin is probably new, although 

 it may be, as he remarks, but the C. maximus of Ehrenberg. 



The following are its characters : — 



C. squamatus. — Elongate, narrowed at 

 its anterior third, but expanded in its 

 posterior half. 1-130" to 1-135". Co- 

 vered with short hairs, which are dilated 



in a scale-like form toward the base, and 

 regularly imbricated. In long-kept sea- 

 water brought from Toulouse. 



Genus SACCULUS (Gosse) (XL. 17, 18).— One eye, frontal; body desti- 

 tute of hair, and without a foot ; rotaiy organ a simple wi'eath ; alimentary 

 canal very large ; jaws set far forward, apparently consisting of two dehcate 

 unequal mallei and a slender incus ; very evanescent ; eggs attached behind 

 after deposition. 



This genus comes nearest to GlenojyJwra, but, luilike the latter, has but 

 one eye. Forty's genus Ascomorpha appears identical with Saccidus. 



Sacculus viridis. — Pear-shaped ; flat- 

 tened ventrallv, the anterior end the 



nari'ower ; head conical-pointed, sur- 

 rounded by a ^\Teath of long cilia ; di- 

 gestive canal occupying nearly the whole 

 body, and alwa3^s filled with a substance 

 of a rich green hue in masses. 1-150". 

 This curious animal, found in consider- 

 able number in a little pool on Ilamp- 

 stead Heath, must be placed in this 



family, according to Ehrenberg's system ; 

 but the mode of carrying its eggs indi- 

 cates an afiinity with the Brachionaea. 

 The AscomorpJia gcfnamca of Leydig is 

 identical with the above species. 



Mr. Gosse has ascertained that this 

 species is dicecious. XL. 17 represents 

 a newly-born male, and 18 a female with 

 ova attached. 



Genus GLENOPHOEA (XXV. 359).— Eyes two, placed anteriorly; rotary 

 organ frontal, circular ; tail bifid, truncated. The alimentary canal is short, 

 thick, and conical ; it sometimes contains green matter. The two protruding 

 forceps-like bodies in the middle of the rotary organ may, says Ehrenberg, 



