4 Transactions of the Society. 



Mr. Hood had not only noticed them, but he had the good 

 fortune, which I have not had, to see how they were used, and to 

 watch the rotifer building his tube. As is the case in all the tube- 

 makers, there is an inner gelatinous tube generally of considerable 

 thickness, and this is secreted by the rotifer itself. The outer case 

 is formed by faecal pellets, which are laid one by one in spiral 

 curves round the inner one ; a mode of fortifying tlie tube, which 

 is adopted also by (E. pilula. The pellets adhere pretty firmly 

 together, and must make a very efficient protection for the timid 

 and delicate creature within, for I watched an annelid doing its 

 best to pull a tube to pieces, and though the worm nibbled at the 

 pellets, and roughly pushed the tube backwards and forwards for a 

 considerable time, it seemed quite baffled by its toughness and 

 elasticity, and went away at last leaving the rotifer, who was hauled 

 down close at the bottom of the tube, unharmed within. 



In building its tube, Mr. Hood says that " the animal does not 

 appropriate every faecal pellet as it is voided, but only one now and 

 then as occasion requires. It generally stoops to emit a pellet, 

 and having done so allows the pellet to float away, but when it 

 means to use it for the tube, it takes an erect position and seizes 

 the pellet by the bristles, Fig. 3, r, above the knob, and retires 

 with it a short distance into its tube ; it then stoops its head and 

 places the pellet on the edge of the tube, pushing it off the bristles 

 by the help of the knob." 



Mr. Hood also informs me that he has seen the male, and that 

 it much resembles that of Melicerta tuhicolaria. Of the young 

 female, he says that it takes four days after it is hatched to acquire 

 its perfect form, and ten days to acquire its full growth. This 

 seems a slow rate of growth for so minute a creature, but some of 

 the rotifers take longer still ; for instance, I once had the oppor- 

 tunity of watching the growth of a young Cephalosiphon Limnias, 

 and it took quite twelve days to attain to half the size of the 

 full-grown animal. 



Floscularia trifolium. 



Mr. Hood has also discovered another striking novelty in Loch 

 Lundie, viz. a very large Floscule, having only three lobes, and 

 of great transparency and beauty ; indeed, as its discoverer well 

 says, " the belle of the rotifers." At first sight I thought it 

 was F. trilobata, described by Dr. Collins in ' Science-Gossip,' 

 January 1872 ; but the differences between Dr. Collins' descrip- 

 tion and Mr. Hood's rotifer are great. 



F. trilobata is said to have much shorter setae than other 

 Floscules have, to have its dorsal lobe generally much larger 

 than the other two, and to have a very long cloaca running up 

 the side of the body opposite to the dorsal lobe, and ending between 



