BDELLOID ROTIFERA OF SOUTH AFEICA. 49 



posteriorly. It was soon apparent that there were other abnor- 

 malities about the creature, and that it was so aberrant — although 

 an undoubted Bdelloid — that it could not be placed in any of the 

 three families as given in Bryce's classification of the Bdelloid a 

 I have therefore constituted a new family for this animal : 



MoNOCEROTiDAE fam. nov., 



Bdelloida having, on the penultimate segment of the foot, 

 one spur only. 



The MoNOCEROTiDAE differ from all other known Bdelloida 

 in possessing only one spur. That they are Bdelloids, I think 

 there can be no doubt. In their habits they resemble Micro- 

 DiNiDAE and Adinetidae, but on the whole come nearest to 

 MiCRODiNiDAE ; but the differences are very great. The jaws 

 in each are abnormal, but not of the same type. The corona is 

 very meagre in Monocerotidae, but wanting altogether in 

 MicRODiNiDAE. Both possess four toes, but in Monocerotidae 

 the toes have each a separate external sheath. 



In all other details, not already referred to, there seems to be 

 no great difference from Bdelloida in general. 



MONOCEROS gen. nov. * 



Generic Characters. — Having one spur only ; fouEr toes, and a 

 fully developed rostrum. The corona is inconspicuous or obscure. 

 Jaws are abnormal. 



Two small circular arrangements, with not the slightest 

 semblance of pedicels, situated on a prone face, represent the 

 corona in Philodina. The gullet is extremely short. 



Monoceros falcatus sp. nov. 



PI. 2, figs. l-ld. 



Specific Characters. — Rostrum well developed, with strong 

 cilia. Corona inconspicuous — a sessile rotulate arrangement 

 bearing rather feeble cilia on the rims and possibly no cilia 



* Since the above was in type I have learned that the generic 

 name Monoceros is already pre-occupied and according to the rules 

 of nomenclature is ineligible ; this also applies to the ordinal name 

 as well. It is intended to rectify the error in Part II of this paper. 



JouRN. Q. M. C, Series II.— No. 78. 4 



