ZOOLOGISCHE MEDEDEELINGEN 



UITGEGEVEN VANWEGE : 

 's RIJKS MUSEUM VAN NATUURLIJKE HISTORIE 



Deel VI. 



te 

 LEIDEN 



Aflevering 2—3. 



VI. - A REVIEW OF THE FAMILY OF HESIONID AE,W^H,, 7^7 

 A DESCRIPTION OF TWO NEW SPECIES. Y>^" 



BY Dr. R. HORST. 



* DEC 21 1921 



Occupied with the examination of Hesionidae from the u)utch East- 

 and West-Indies I found not only, that some genera of this^infuy, are 

 described under several different names, but also, as already stated by 

 Webster and Benedict, that the genera seem to be badly confused l ) ; 

 Leocrates Kbg. f. i. is identical with Lamprophaës Gr. and Tyrrhena Clap., 

 and Podarke pallida was ranged by Claparède among the genus Oxydro- 

 mus whereas Podarke angustifrons according to Grube belongs to the 

 genus Irma. Partly this might be ascribed to the circumstance, that 

 sometimes not full-grown specimens were described, partly to the fact 

 that the, cephalic appendages were overlooked, either in consequence of 

 their minute dimension or because they were fallen off. Because in the 

 last years our knowledge of this family much increazed thanks to the 

 arduous investigations of Fauvel, Me Intosh, Gravier, Southern a. o. and 

 the description of the species is scattered through a great number of 

 publications, I tried to give in the present paper a review of the genera 

 and an enumeration of all the species hitherto described. Though I am 

 convinced, that no doubt several species may be overlooked, I hope 

 however that my list might be of some use for my colleagues. 



Whereas Ehlers 2 ) and Grube 3 ) made use of the number of cephalic 

 appendages as a charakter to distinguish the different genera from each 

 other, Gravier 4 ) based his main divisions of the family on the uniramous 

 or biramous condition of the parapodia ; however I am agreeing with 

 Ehlers' opinion, that this charakter is less suitable for the distinction of 



1) The Annelida Chaetopoda from Provincetown and Wellfleet, Ann. Rep. Commiss. Fish 

 and Fisheris for 1881, p. 709. 



2) Die Borstenwiirmer, p. 187. 



3) Mitth. üher die Familie der Phyllodoceen nnd Hesioneen, 1879, p. 16. 



4) Annélides Polychètes de la Mer rouge, Nonv. Arch. Muséum d'Hist. nat. (S ér. 4), Vol. II, 

 1900, p. 170. 



(1«— x— îy^i) 



