124 on a new meliceetian 



On a New Melicertian and Some Varieties of Melicerta 

 KiNGENs. By J. G. Tatem, 



Of the Reading Microscopical Society. 



Some years since, a friend submitted to my examination a 

 Melicertian, which could not be assigned to any known genus. 

 Drawings were carefully made at the time, with the aid of the 

 neutral tint reflector, and copies of these I now beg leave to lay 

 before the members of the Quekett Club. 



It will be seen that the new rotifer bears a general resemblance 

 to Limnias ceratophylli, from any close alliance with which, it is, 

 however, removed, by a higher type of organisation. A viscid 

 sheath, to which excrementitious and extraneous matters adhere, 

 equally characterises this species and Limnias ; but it is slightly 

 curved and more contracted at the base. The rotary disk is 

 bilobed, a double wreath of cilia surrounding its margin. Two 

 well developed water vascular canals or siphons, conspicuously 

 prominent when the animal is seen emerging from its sheath, 

 would indicate a nearer structural approximation to Melicerta than 

 to Limnias, in which these organs are altogether wanting. The 

 pharyngeal bulb also bears a close resemblance to that of Melicerta. 

 Length of sheath ^ ; of extended animal, about -Jg-. 



In the Quarterly Journal of Microscopic Science (1867, p. 14), 

 Mr. Davis described a rotifer under the name of (Ecistes longi- 

 cornts, which appears to be nearly allied to the one now described 

 and figured, which that gentleman felt a cUfficulty in consigning to 

 any recognised genus, and while calling it an fficistes, and noting 

 its resemblance to Limnias, evidently considered it as belonging to 

 neither. Should it not rather have been brought forward as the 

 type of a new genus, in which the Tubicola I figure would have 

 found its place ? While, therefore, for the purpose of artificial 

 classification, venturing to constitute a new genus for their recep- 

 tion, for which the name of Limnioides is proposed, and the specific 

 one of myriophylli for that now described, I would yet enquire if 

 many of these animals are, after all, so generically distinct? 

 Whether through variability such connecting hnlvs may not even- 

 tually be met with as to afford reasonable grounds for suspecting 

 an insensible graduation into each other ? Found on MijriophijUum 

 spicatum and Ranunculus aquatilis, associated with Melicerta 

 ringens and Cephalo siphon Limnias, the idea not umiaturally pre- 



