1Q9 



NOTES ON THE ROTIFERA. 



By J. Cash, Wareington. 



No. 2. — Melicerta Ringens. 



This rotifer, which, according to the old arrangement, forms a genus of 

 itself, is distinguished by the following characters, according to Pritchard. 

 " Case of a brownish red colour, composed of small lenticular (?) bodies, 

 deposited by the animalcule ; rotary organs simple, with four lobes when 

 expanded ; alimentary canal divided into segments, in one of which (the 

 pharyngeal bulb) are complex jaws ; mouth situate at the bottom of the 

 cleft, between the two large lobes of the rotary organ. Male generative 

 organisation unknown. Two water-vascular canals arising from a con- 

 tractile vesicle ascend towards the head. There are two tactile appen- 

 dages with setigerous extremities on each side of the head, and two eye- 

 spots in the young animal." 



This is almost as common a rotifer as any we have in the neighbourhood 

 of Warrington, and if not the most beautiful, it is at any rate the most 

 interesting of the whole class, from the fact that instead of merely secret- 

 ing a gelatinous case, like the Stephanoceros, in which to live when it has 

 reached maturity, it builds for itself a house, using for the purpose bricks 

 of its own moulding. It is this habit of building which distinguishes it 

 from all other members of the class, and which, I think, should keep it 

 distinct, however much resemblance there may be in regard to internal 

 organisation. Mr. Gosse, however (see Popular Science Review, vol. i., 

 p. 481,) takes nine genera, each containing a single species, and reduces 

 them to two, giving the generic name of Melicerta to the following : — 

 Ptygura, CEcistes, Tubicolaria, Limnias, Melicerta, and Cephalosiphon ; while 

 MegalotrocJia, Lacinularia, and Conocliilus, constitute another genus, to 

 which he gives the name of MegalotrocJia. These two new genera are dis- 

 tinguished by the circumstance that in the former the individuals are 

 always solitai7 ; in the latter they are (in adult age) aggregated by mutual 

 adhesion into somewhat spherical masses, composed of many animals radi- 

 ating in every direction from a common central point of adhesion. 



^0. 9, September 1. K 



