227 
On a New Melicerta. By Dr. G. T. Hudson. 
flexibility of the antennae. The animal reminds one at once of 
Mr. Davis’ (Ecistes longicornis. Of course I was very curious to 
know if it possessed its kinsman’s ciliated cup for making pellets. 
Whether it was a Melicerta without a pellet-cup, or whether, having 
the apparatus for making pellets, it failed to make use of it, — in 
either case its condition was a strange one. With some difficulty I 
so clipped the leaf which a specimen was on, as to get the creature 
comfortably placed in a compressorium ; and although it was 
limited to a very thin plate of water, it still continued to come out 
of its sheath and to unfold its disk. I then distinctly saw that it 
possessed a ciliated cup (Fig. 3, b) with thick edges, but without a 
trace of any extraneous matter revolving in it. Now the gelatinous 
sheath is excreted in some way by the animal, but as similar sheaths 
are excreted by Stephanoceros, (Ecistes, and Floscularia, which 
have no ciliated cups, what is the use of the cup in this new Meli- 
certa ? Has it really had the organ given it not for its own use, 
but in order that a more highly developed relative might have an 
improved and effective form of it, without too great a break in the 
ascending series of animal life ? 
I think it possible to give a simpler solution of the riddle. 
Most of the rotifers have in some parts of their bodies organs for 
secreting a viscous fluid ; in the great majority of cases they lie at 
the extremity of the foot ; either at the ends of the pincers as in 
Synchseta or Euchlanis, or in a ciliated cup as in Pterodina, or on 
two ciliated projections at the posterior end of the body as in 
Pedalion. The Philodines can secrete this fluid in great abun- 
dance ; and, as Mr. Davis has conclusively shown, so encase 
themselves with it as to resist the destructive effects of a high 
temperature and absolute dryness. The tube-makers have this 
secreting organ below the mouth and nearly midway between the 
antenna?, and on or near it fall atoms which have made the circuit 
of the trochal disk in the groove leading to the mouth, and which, 
rejected by the organs of taste at the entrance to the buccal funnel, 
have been hurried over the ciliated chin. 
These atoms mix with the viscous secretion and accumulate 
round about the neighbourhood of the gland ; till the animal, 
apparently annoyed by their presence, contracts itself with a 
sudden twist and rubs them off on to its tube by a sideway motion 
of the head, which is characteristic of the Melicertidas. In this way 
the gelatinous sheaths are strengthened and frequently rendered 
quite opaque. When the creatures grow in very clear water their 
sheaths are so free from foreign bodies as often to be quite trans- 
parent. If paint is put into the water (as has been often shown) 
it soon appears in the newly formed portion of the case. In the 
‘ Transactions of the Boyal Microscopical Society,’ 1867, Mr. Davis 
has given an excellent drawing of the tubes of (Ecistes enlarged by 
