34 M. J. de Guernc on the 



ASPLANCHNOPUS, gen. nov. 

 (Etymology : Asplanchna and ivovs, foot. ) 



Diagnosis. — Femina. Corpus ovato-globosum, pellucidum, pede 

 bifldo minimo ventrali instructum ; maxilla) duo bus tantum ramis 

 composita) ; rami incurvati, validi, apice acuto simplici. 



Asplanclinopus generi Asplanchna dicto ceterum valde aifinis. 



Mas ignotus. 



This Rotifer must also resume the specific name multiceps, 

 which was given to it by Schrank as long ago as 1793, and 

 which Ehrenberg changed in opposition to the rules of 

 nomenclature. 



Asplanchnopus muUiceps^ Schrank (sp.). 



1793. Brachionus muUiceps, Schrank, " Mikroskopische Wahrnchmun- 



gen," in Naturforsclier, vol. xxvii. p. 30, pi. iii. figs. 16-19. 

 1803. Brackionus 7nitlticej)s, Schrank, Fauna Boica, vol. iii. pt. 2, 



p, 139. 

 1835. Notommata myrmeleo, Ehrenberg, " Dritter Beitrag &c.," in 



Abhandl. Akad. Wiss. zu Berlin, 1833, pp. 214_, 215. 

 1838. Notommata myrmeleo, Ehrenberg, Die Infusionsthlerclien, p. 425, 



pi. xlix. fig. I, 1-3. 

 1854. Notommata myrmeko, Leydig, " Ueber den Bau &c. der Rjider- 



thiere," in Zeitschr. f. Aviss. Zool. Bd. vi. pp. 20-24, pi. iv. fig. 36. 



1884. " Deadly enemy to Chydoj-us," llerrick, " Final Report &c." in 

 Twelfth Ann. Rep. Geol. and Nat, Hist. Survey of Minnesota, pi. v. 

 figs. 10, 11. 



1885. Asplanchna myi'meleo, Plate, " Beitrage zur Naturg. der Rota- 

 torieu," in Jenaische Zeitschrift, Bd. xix. pp. 73-83, pi. iii. figs. 31- 

 33, 35, 36. 



1885. Asplanchna magnijicus? , Herrick, "Notes on American Rotifers," 

 in BuU. Sci. Labor, of Denison University, vol. i. p. 60, pi. ii. fig. 2. 



Considering the instruments which he had at his disposal, 

 Schrank very well investigated Asplanchnopus multiceps. 

 The name that he gave it, however, has its origin in an error 

 of observation, which was likewise committed by Ehrenberg. 

 These naturalists mistook for so many rotatory organs the 

 groups of cilia which better means of investigation have 

 enabled us to study more completely. Further, both of them 

 regarded the rudiment of the foot as lateral, whilst it is in 

 reality ventral, as Leydig was the first to indicate *. 



At any rate the " vielkopfiges Kapselthier " furnished 

 Schrank with the subject of interesting observations. He 

 says that it is met with frequently in stagnant but clear 



* Leydig, loc. cit. p. 20, pi. iv. fig. 30. See also Plate, loc. cit. pi. iii. 

 fig. 31. 



