42 THE ROTIFEEA. 



descends, as if to make the lorica two-jointed. The foot narrow, but a little widened 

 at its end, just protrudes from under this plate, and bears the toes, jointed to it with 

 small round condyles. They are almost rod-shaped, but there is a hardly perceptible 

 curvature of their lateral margins. But the most noteworthy feature is tttat both the 

 lateral margins of each toe are abruptly shouldered ; and the little claw-like remainder 

 has the acute tip recurved. The mallei are long, strongly elbowed, and unusually 

 slender. An eye, of moderate size, richly coloured, lies far down in the occiput. The 

 dorsal plate is coarsely tesselated, as in C. rusticula. Several specimens have occurred 

 in water sent to me by Mr. Hood, from Black Loch, near Dundee. 



Length (of lorica), ^^ inch ; (total) y^j inch. Habitat. Lacustrine. P.H.G.] 



CATHYPNA LATIFBONS, Gosse (170), (PI. XXXI. fig. 87). 



[SP. CH. Lorica broadly ovate, the frontal edges little diminished, both straight ; 

 the occipital much wider than the pectoral ; toes broadly blade-shaped, much produced, 

 not shouldered. 



Another of the rarities of the prolific Black Loch. The outline is that of C. rusticula, 

 if we suppose the anterior fourth of the lorica to be cut off transversely. But the ventral 

 plate is less in area, all round, than the dorsal, especially forward, narrowing more 

 rapidly, and terminating lower down. There is a considerable rounded boss behind, as 

 in both the preceding, below (or within) which are the foot-joints, but not protruded. 

 The toes have the inner edge straight, and the outer much outcurved ; so that, when they 

 are held in contact (as they usually are), the pair present an outline widely fusiform. 

 Then the points are drawn out to great length and tenuity, with an effect very peculiar. 

 The front of the lorica forms two stiff lateral points ; within which the margins, both 

 occipital and pectoral, seem to be thinned-off to very delicate membranes, so as to be 

 capable of extension and retraction. When closed, the occipital edge is, I think, straight 

 from point to point, and concave inward. Then the pectoral edge is appressed to the 

 concave dorsal surface (but at a loiuer, i.e. a hinder, level) ; and that so close as to be in- 

 distinguishable from it, even by most careful focusing with high powers. The internal 

 organs seem normal. 



Length (of lorica), ^\^ inch. Habitat. Lacustrine. 



CATHYPNA UNGULATA, Gosse (170), (PI. XXXI. fig. 36). 



[SP. CH. Generally like C. luna, but occipital edge of lorica nearly straight ; pec- 

 toral edge indented in the middle ; toe rod-shaped, straight, very slender ; claw one- 

 shouldered, one-third of toe's length. 



This is more than twice as large as C. luna. Moreover, the frontal edges of the lorica 

 are nearly straight, between very slight lateral points, and alike, save that the line of 

 the pectoral edge (fig. 36, b) descends from each point to a medial angle, just percep- 

 tible. Then, the hind extremity of the dorsal plate allows the partial emission of a great 

 protuberant shelly boss, as in Monostyla bulla, behind and beneath which is the globose 

 foot-bulb. Again, the rod-like toes are even straighter and slenderer than in luna, and 

 the claws are much longer in proportion. Parallel-edged to two-thirds of their length, 

 a right-angled shoulder, on the outer side, reduces the width by one-half; and the re- 

 mainder (the claw) tapers to a long-drawn acute point (d). When rotating, the truncate 

 front is three-lobed, much as in luna ; but there is seen beyond and above this a very 

 subtile clear glassy hood, having a rondo-conic outline, protrusile and retractile. 



Length (total), -fa inch. Habitat. Woolston pond. P.H.G.] 



DISTYLA HOBNBMANNI, Ehrenberg (PL XXXIII. fig. 37). 

 Euchlanis Hornemanni ..... Ehrenberg (42). 



SP. CH. Lorica smooth, short, semi-orbicular, broadly truncated in front, and 

 without lateral points ; the former part of the body soft, flexible, and much elongated ; 



