On (Ecistes Janus, &c. Bij C. T. Hudson. 5 



the two smaller lobes on the level of their basis ; and although said 

 to be one of the " largest of the Floscules," its " total length " is 

 given at ^\ of an inch. 



Now F. trifoUum has setae of about the usual length, its 

 dorsal lobe is only slightly larger than the other two, its total 

 length is -^^ of an inch, and its cloaca and vent (as in all other 

 Floscules I am acquainted with) are on the side of the dorsal lobe. 

 It is possible that the two animals are the same, for there must, I 

 think, be at least one grave error in Dr. Collins' description, viz. 

 that as to the cloaca ; but as I have to choose between the possible 

 error of describing two different rotifers under the same name, or 

 the same rotifer under two different names, I have thought the 

 best course to be to call Mr. Hood's Floscule trifolium, and give 

 trilohata a chance of putting in an appearance on some other 

 occasion. 



Dr. Collins also states that F. trilohata has its setae arranged 

 in an unusual manner, " being placed between their lobes as well 

 as on their summits, forming a kind of unbroken fringe along the 

 entire margin of the disk." 



Now in F. trifolium, the setae are also set along the entire 

 margin of the disk, but the arrangement is not novel, for it is 

 exactly the same in F. campanulata. The fact is that the setae in 

 these Floscules are so placed that it is impossible to see all those 

 on one lobe at once. -No three of them are in the same plane. 

 While those on the top of the lobe point forwards from the body, 

 those at the bottom of the lobe actually point backwards towards 

 the foot, and as they pass down the margin of the lobe from 

 its highest to its lowest point, their inclination constantly changes 

 so as gradually to alter from the first of these directions to the 

 latter. The consequence is that, look at the lobe from what point of 

 view you will, many of the setae must be invisible, as they are actually 

 pointing right up the Microscope. Then again, although really 

 very long, they often look short from their curvature taking their 

 upper portions right out of focus. F. trifoUum has, however, 

 a second smaller row of setae, much shorter, and running round 

 each lobe parallel to the larger fringe, and curved inwards. This 

 arrangement is shown in Plate II., Fig. 3, and is, I believe, 

 peculiar ; at least I have never noticed it in any other Floscule. 

 If any small floating atom attempts to escape from the meshes of 

 the living net formed by the interlacing setae, a swift wave of 

 motion is seen to run all along the smaller row, and it is often 

 caught and thrown back into the hollow globe formed by the three 

 lobes. 



The first thing that strikes the observer on watching the furled 

 head protrude from its tube is the great size of the rotifer, and the 

 curiously shrivelled appearance that the lobes of the trochal disk 



