so THE ROTIFERA. 



in consequence, separated it from the Welicertadce, and placed it in a family named 

 after itself : an honour it did not deserve. The antennae vary greatly in length in the 

 ill I'l'c rent speeies : some are mere setigerous pimples, others the longest known among the 

 Eotifera. 



The internal structure, so far as it has been ascertained, is that of Melicerta. The 

 parts not made out are the vascular system and the nervous system. The male also is 

 unknown. 



(E. crystallinus, Ehrenberg. 



I PL VII. fig. 3.) 



CEcistes crystallinus . . . Ehrenberg, Die Tnfus. 1838, p. 392, Taf. xliii. fig. 7. 



,, ... Pritchard, Infusoria, 1861, p. 663, pi. xxv. figs. 361-304. 



Melicerta crystallina . . . Gosse, Popular Sci. Rev. vol. i. 18112, p. 490. 



SP. CH. Ventral antennae extremely short, and set wide apart ; tube most variable 

 and irregular in slw/pe, often beset with extraneous matter. 



I have frequently met with this llotiferon in dense colonies, whose dirty-brown tubes 

 gave quite a rusty look to the water plants which they infested. Though small, it is a 

 very pretty object ; and, with a little care, the secondary wreath of cilia, the two 

 antennae and the dorsal gap in the ciliary wreath can be distinctly made out. For this 

 purpose the animal must be so placed that its long axis is nearly in the line of sight. 

 From almost all other points of view the dorsal gap is invisible, and only one antenna 

 can be seen at once, owing to the unusual width between the two. When the case is 

 free from rubbish, it is not difficult to see that the animal's internal structure is very- 

 like that of Melicerta. The vascular system and the nervous system have not yet been 

 observed. Two red eyes are visible in the half-grown young. 



Length. About .',, inch. Habitat. Ponds and ditches : very common. 



(E. INTERMEDIUS, Davis. 



(PI. VII. fig. 5.) 

 CKcistes intermedius . . . Davis, Trans. Roy. Micr. Soc. vol. xv. 1867, p. 14, with Bg. 



SP. CH. Antennae short; dorsal gap unusually wide; tube opaque, tapering 

 slightly from top to bottom. 



Mr. Davis found this species at Leytonstone, in company with the former. It 

 differs from CE. crystallinus in the width of the dorsal gap in the ciliary wreath, which 

 almost approaches that of a Limnias, and in its neat tube, which exactly reproduces that 

 of L. ceratophylli. In fact, had it not been for its distinctly oval corona, I should have 

 said that it was a variety of the latter species. Mr. Hood, however, tells me that he has 

 found it (sometimes in abundance) in Scotland and always with the oval disk ; Mr. Gosse, 

 too, has seen many Scotch specimens, and has no doubt that it is a true species. 



[Two specimens, so young that no visible tube was begun, yet attached to a stem by 

 the foot, showed, in the wall of .the occiput just below the ciliary rota, two well-defined 

 and conspicuous dark eyes, rather far apart. — P. H. G.] 



Length. About .j 1 - inch. Habitat. Leytonstone, Essex (H. Davis) ; marsh pools, 

 Fife and Perth (J.H.) : not common. 



(E. serpentinus, Gosse, sp. nov. 

 (PI. IX. fig. 1.) 



SP. CH. Corona small, circular ; foot fully thrice the length of the body, much 

 wrinkled, extensile ; ventral antenna a single, simple tubercle ; a pair of dorsal hooks 

 below the corona, aclnate at the base ; tube very short, or absent. 



