MUSEUM OF COMPARATIVE ZOOLOGY. 143 



The title of one of Claus's valuable papers on the Siphonophorse is Die 

 Gattung Monophyes und ihr Ahkommling Diplo2:)hysa, in which he sup- 

 ports the idea that Diplophysa is a diphyozoid of Monophyes gracilis, Cls. 

 He makes Huxley's genus Spheronectes a synonym of Monophyes. He 

 repeats in his Grundzilge der Zoologie, 3 Auf., 1876, that Diplophysa 

 inermis is a diphyozoid of Monophyes gracilis, as stated above. 



Metschnikoff (Studien liber die Medusen und Siphonophoren, p. 46) 

 says, concerning the relationship of these animals, that fragments of the 

 form Pray a inermis were described by Gegenbaur as Diplophysa inermis. 

 He bases his idea of the relationship of these two genera on the identity 

 of the larva of Pray a, which he describes, with the remarkable genus 

 of Gegenbaur, and more especially on the resemblance in the form of 

 their nectocalyces. He adds also, that both genera are of small size, 

 which cannot, if taken alone, be a very strong argument for their 

 relationship. 



VOL. VI. — NO. 7. 



