J. MURRAY ON GASTROTRICHA. 219 



Note. Anacanthoderma can hardly be separated from Dasy- 

 dytes, as the only species is described as having some bristles. 

 Aspidiophorus is a Chaetonotus, having the bristles enlarged at the 

 apex, scarcely a generic distinction, as those having enlarged 

 bases are not considered generically distinct. Gossea is usually 

 put in the Apodina, but Daday's two species possess the furca, 

 and Gosse's antenniger with its caudal bundles of setae may be 

 said to possess the homologue of the furca. Setopus primus 

 is scarcely distinguishable, even as a species, from Dasydytes 

 bisetosus Thomp., yet from the possession of a slight medial 

 depression at the posterior end it has technically a furca, and 

 becomes a distinct genus. 



List of all Species which have been Described. 



In alphabetical order, and under the original generic names, 

 with critical notes on synonymy and specific values. 



1910. Anacanthoderma punctatum Marcolongo (40). 



1902. A sp)idonotus paradoxus Yoigt. (65). Now a genus Aspidio- 



phorus. 

 1865. Cephalidium longisetosum Met. (41). Is a Dasydytes. 

 1773. Cercaria podura Mull. (42). Now the type of Ichthydium 



Ehr. 

 1887. Chaetonotus acanthodes Stokes (57). 

 1887. C. acanthophorus Stokes (57). 



1903. C. arquatus Voigt. (67). 

 1832. C. breve Ehr. (16). 

 1889. C. brevispinosus Zel. (71). 

 1901. C. chuni Voigt. (64). 



1887. C. concinnus Stokes (57). Is a Lejndoderma. 



1910. C. decemsetosus Marco. (40). 



1905. C. dubius Dad. (14). 



1887. C. enormis Stokes (57). 



1905. C. erinaceus Dad. (14). 



1887. C.formosus Stokes (59). 



18(54. C. gracilis Gosse (24). 



1905. C. heterochaetus Dad. (14). 



1910. C. hirsutus Marco. (40). 



1865. C. hystrix Met. (41). 



