CATHYrNAD.E. 93 



witli two equidistant incisions, at each of wliicli appears a bristle (fig. 4). Tlie rotating 

 cilia are set along the edge. A mastax of very ample dimensions, with a pair of long 

 mallei, but rather small incns, is always conspicuous. Behind this the occipital brain 

 carries an eye, usually large and brilliant. A great saccate stomach, without sensible 

 CGsophagus, with large gastric glands, and followed by a separate intestine, passes 

 obliquely across the dorsal region ; and the ovary, as usual, occupies the ventral. • In 

 the adult, ihe surface of the lorica is smooth, and the whole animal is transparent and 

 colourless. 



Though individuals swim actively now and then, yet the habitual sluggishness and 

 inertia of the species camiot fail to attract attention. As described, it will balance 

 itself, by the hour, on its united toe-tips, with an occasional lazy swaying to and fro ; 

 or even loosen this feeble hold, and allow its body to sprawl away at right-angles to the 

 food-surface, free in the water, the foot being bent up to the belly. — P.H.G.] 



Length. Total, j-i^ inch ; of lorica, -[ij inch. Habitat. Fresh waters (P. H.G.) : 

 common everywhere. 



C. KusTicuLA, Gosse, sp. nov. 

 (PI. XXIV. fig. G.) 



[SP. CH. Lorica regularly ovate, with the frontal opening very narrow; dorsal 

 surface coarsely tesselated ; ventral plate nearly flat ; toes blade-shaved. 



This fine species is very hyaline, notwithstanding that the broadly-oval and arched 

 surface is cut into facets. These are not very regular, nor very distinctly marked, having 

 the appearance of folds in leathery skin. They appear to be limited to the carapace. 

 This is turned-in along each side, with a sharp lateral angle meeting the edge of the 

 ventral plate, similarly turned-in, as is clearly seen when the creature is viewed from 

 behind (fig. Gb). The union is doubtless completed by a flexible and extensible membrane. 



The head is included between firm plates, which, seen vertically (fig. C), appear as 

 two lateral projecting points, between which the fi'ont, of many conical lobes that carry 

 vibratile cUia, works to and fro. The bram and its lozenge-shaped eye are normal ; and 

 so are the great trophi, the stomach with trigonal gastric glands and distinct intestine, 

 and the ovary. A contractile vesicle is sometimes conspicuous, but no details of the 

 respiratory nor of the muscular systems have been defined. A rather thick and short 

 foot, rounded laterally, bears the two toes, which are articulated with round condyles. 

 They are moderately thick blades of fusiform outline, when seen laterally, thinner 

 towards the base, and rather bluntly pointed. 



I first met with this form, in July 1885, in the sediment of water in which aquatic 

 weeds had been sent from the north of London. Subsequently other examples occurred, 

 in water from Caversham and Woolston, and from near Dmidoe, in December. 



The earlier specimens were even more clumsy and sluggish than ordinary, moving 

 waywardly from side to side, as if not quite under control, adhermg all the while by the 

 toes. Hence I called it rusticiila. This, when too late, I would have changed ; for some 

 were much more attractive, transparently beautiful, with the eye large and of a lovely 

 rose-piak hue, and so sprightly in manners as to be worthy of a more courtly designa- 

 tion. Ill these, too, the digestive canal was distended with food of a clear rich orange- 

 brown hue. These were Woolstoii specimens. Scottish examples bred freely and in- 

 creased in my phials. — P.H.G.] 



Length, yJ-jj inch. Habitat. Pools throughout England and Scotland (P. H.G.) : 

 common. 



' In one example the ovary was fastened, by two threads with swollen enlargements, to each side of 

 the lorica, near the middle ; and the gastric glands were also tied to the same points (tig. 4). Long 

 threads (muscular ?) with like enlargements were seen to pass from the foot-bulb tu near the same 

 points, if not higher. 



