92 THE ROTIFERA. 



the dorsal plate. The outline of the dorsal portion of the lorica, when seen directly 

 from the front or rear (fig. 4c), is triangular ; the section, so obtained, having a base 

 just twice its height. There is a well-marked occipital notch (fig. 46) in the dorsal 

 plate, through which a short, stout, dorsal antenna usually protrudes. Dr. Grenadier 

 has detected two dorso-lateral antennae close together " lying near the crest of the 

 lorica." Ehrenberg says that there are no setae on the foot ; but I have never failed to 

 find two when using dark-field illumination. The rest of the structure requires no 

 further notice, as it is a tolerably close repetition of that of E. lyra. 



This is one of the choicest of microscopic objects, when shown in a dark field ; 

 especially when it is quietly gliding over and round a few tangled algaa. Its strange 

 armour is now invisible, and now blazes out as it catches the light ; while the ruby eye, 

 the daintily-tinted stomach studded with glittering drops on canary-coloured quiltings, 

 the ruddy intestine softened by the tremor of its ceaseless cilia, and the restless head 

 crowned with an ever- varying halo of flashing setoa, form a picture that once seen can 

 never be forgotten. 



There is a variety of E. triquetra, with a lower vertical plate, which I have met 

 with now and then ; and which, on several occasions appeared to have but one long seta 

 on the foot. Possibly this is Leydig's E. uniseta (PI. xxiii. fig. 3). 



Length. Up to ^ 5 inch. Habitat. Clear ponds and ditches : not uncommon. 



E. DEFLEXA, 



(PL XXIV. fig. 1.) 

 Euchlanis dcflcxa . . . Gosse, Ann. Nat. Hist. 2 Ser. vol. viii. 1851, p. 200. 



[SP. CH. Outline of lorica ovate; ventral gape wide, equal, with deep walls ; 

 toes broad, Uade-sliaped ; lateral horns of incus straight. 



This is a large and very beautiful species. It is not to be distinguished at first sight 

 from a true Euchlanis, but the carapace, which is highly arched, turns in at the lateral 

 edges, and after proceeding for a space horizontally, i.e. across the ventral surface, is 

 bent down at a right-angle to a considerable width and then terminates, as if we might 

 suppose the ventral plate to have been originally flat and continuous ; then to have been 

 slit down the middle, and each side to have been bent down at a line midway between 

 the slit and the outer margin. Thus the abdominal cavity is enlarged, and the viscera 

 are protected only by the common integument which is stretched across from edge to 

 edge. This being flexible, a variation of contained space is allowed, for development of 

 eggs, for distension of the alimentary canal, c., which, in Euchlanis, is obtained by the 

 flexibility of the skin that connects the two plates. The lorica is almost circular behind, 

 where a very minute central notch admits the two sides to overlap in the slightest pos- 

 sible degree. The foot issues, of course, from the ventral hiatus ; it bears two toes, which 

 are thin, flat, and wider in the middle part. The penultimate joint of the foot proper has 

 on its dorsal side a curved projection, which arches over a deep excavation. It carries two 

 pairs of long setae, one or both of which are sometimes wanting. Each toe has a cor- 

 rugated mucus-gland (?) running through it. The broad head is composed of many 

 (ten ?) transparent globate lobes ; the front is divided into several pairs of lobes, which 

 carry bundles of cilia. The three strong lines which (with the front) form a square, 

 reaching behind the mastax. are puzzling, but I believe they represent the wide, clear 

 brain. The sacculate stomach is enormous, with two gastric glands ; and two glands, 

 beside, are attached to the mastax : there is a small, distinct intestine in which the epi- 

 thelial cilia may occasionally be seen ; a great ovary, with embryonic vesicles, and 

 sometimes one (or more) dark ovum maturing. The branchial tubules, two or more, 

 contorted and very loosely twisted, carrying four vibratile tags on each side, open by 

 two distinct months on each side, into an ample contractile vesicle, just before the cloaca, 

 whose periods are very irregular, even in the same individual : now emptying once in 

 two minutes, then several times per minute. Many muscles arc seen, some indubitably 



