46 THE ROTIFERA. 



COLUEUS LEPTUS, Gosse (170), (PI. XXXI. fig. 46). 



[SP. CH. Lorica, in dorsal aspect, long oval ; in lateral aspect, abruptly excavate 

 behind ; dorsal hind points, acute ; ventral cleft close, insensibly expanding to a long 

 pyriform foot-orifice ; toe a slender style, apparently undivided; foot and toe about half 

 as long as lorica ; one large eye in occiput. 



A marked character, very easily recognisable, is the hind excavation of the lorica, 

 as if a slice had been cut clean out. Examples with this peculiarity are quite common, 

 both from weedy fresh waters, and from rock-pools on our northern and southern coasts. 

 And I can trace no difference between them, save that the marine examples may be 

 a trifle stouter in outline. The toe is a slender produced point, I will not say indivisible, 

 but not, in my experience, divided. Several oil-globules are usually present in the 

 dorsal part of the visceral cavity. 



Length. Extended, -^ inch. Habitat. Lacustrine and marine. P.H.G.] 



METOPIDIA PYGM^EA, Gosse (171), (PI. XXXI. fig. 47). 



[SP. CH. Lorica ovate, much elevated, the back rounded, the edges overhanging ; 

 hind margin rounded ; ventral surface flat ; foot stout, long ; toe apparently single, 

 small, acute. 



This seems the smallest of the genus ; smaller than emarginata, or than triptera, 

 which latter was in sight at the same time, for comparison. It is very transparent and 

 colourless, the viscera only just discernible ; the trophi, though working, were but 

 shadowy lines. The extremity of the lorica is neither pointed, nor sinuate, but evenly 

 round : its overhanging margins are remarkable, recalling Notholca scapha. There are 

 two clear colourless globules at the very front, remote from each other, probably eyes. 

 The frontal hook is carried rather close to the front, and seems incapable of independent 

 motion ; it is visible in a dorsal view, as a line parallel to the front. Two minute air- 

 bubbles were in the alimentary canal of the individual examined ; but no particles, nor 

 stain, of food, though the tiny creature was industriously picking all the time it was 

 under observation an hour or more. It was active and restless, creeping about the 

 floccose, but rarely swimming, and then laboriously. A single specimen occurred in a 

 phial of Utricularia sent by Mr. W. R. Hood, from the middle of Ireland. 



Length. Extended, ^ inch. P.H.G.] 



METOPIDIA OVALIS, Ehrenberg, (PI. XXXIV. fig. 2). 

 Lcpadella ovalis l Ehrenberg (42). 



SP. CH. Lorica depressed, oval, narrowed in front ; dorsal plate truncated at both 

 ends, its margin not excised. 



Ehrenberg draws the ventral plate with a deep, square excision in front, and a small 

 arched one behind. He notices tbat the unci are one-toothed ; the gastric glands cir- 

 cular ; the oesophagus short, and the eyes absent. 



Length, ^ inch. Habitat. Paris, Copenhagen, Berlin (Ehr.). 



METOPIDIA EMARGINATA, Ehrenberg (PL XXXIV. fig. G). 



Lcpadella emarginata . . . Ehrenberg (42). 



SP. CH. Lorica depressed, oval, broad in front ; dorsal plate excised at both ends. 

 Length (without the foot), T V inch. Habitat. Berlin (Ehr.). 



METOPIDIA (?) SALPINA Ehrenberg (PI. XXXIV. fig. 4). 



Lcpadella (?) salpina .... Ehrenberg (42). 



SP. CH. Lorica oblong, prismatic, obtusely triangular with a dorsal crest. 

 This should possibly be referred to Mr. Gosse's genus Diplax. The lorica is ren- 



1 The reasons for uniting the genera Lcpadella, Sqiiamclla, and Mctopidia have been given in vol ii 

 p. 106. 



