302 " ENDEAVOUR " SCIENTIFIC RESULTS. 



Second, the species may all be included under Plumularia, 

 which is the view adopted by Billard. Third, the species may 

 be divided, those with an intrathecal ridge being placed under 

 Diplocheilus, the others under Kirchenpaueria. This is the 

 arrangement adopted by Stechow, in his general summary of 

 the genera. 



For the last division I can see no justification. As I have 

 pointed out in a preceding page, the intrathecal ridge is a 

 feature not at all uncommon in the genus Plumularia, and in 

 several instances it precisely resembles that of K. producta and 

 K. mirabilis. It is obviously of no greater physiological 

 significance in those species than in Plumularia, Lytocarpus, 

 Aglaophenia, Halicornaria, or Sertularia, from which genera 

 no observer proposes to exclude a species on account of the 

 presence or absence of an intrathecal ridge ; and I cannot 

 imagine any reason for applying a different rule to Kirchen- 

 paueria alone among the hydroid genera. 



For Billard's position there is, I think, more to be said 

 nevertheless, although the arrangement of the sarcothecse in 

 Plumularia is far less constant than in the Statoplea, the 

 presence of at least one supracalycine pair is so nearly universal 

 as to afford some justification for the separation of the species 

 wanting that character, especially as those species are peculiar 

 also in the possession of naked median sarcostyles. It is true 

 that among the many Plumularice described by Billard in his 

 " Report on the Siboga Expedition " there is one P. 

 ventruosa which is without lateral sarcothecse, while it is not 

 stated whether any median sarcostyle is present ; possibly 

 this also should be referred to the present genus. 



While the relationship between Plumularia and Kirchen- 

 paueria is obvious, there is evident also a close affinity between 

 the latter genus and Halicornopsis, indeed it is by the great 

 difference in the general facies, dependent nevertheless on 

 minor details, rather than by important structural characters, 

 that the two genera are distinguished. 



KIRCHENPAUERIA PRODUCTA, Bale. 



Kirchenpaueria producta, Bale, Biological Results 

 " Endeavour," ii., 1, 1914, p. 59 (synonymy). 



In the list of synonyms I have included a reference to 

 Inaba's figure of " Plumularia producta " in the Tokyo 

 Zoological Magazine for 1890 ; this must be deleted. As 

 Stechow has pointed out in his revision of Inaba's species, the 

 specimens examined by that observer belonged really to 

 K. mirabilis (Diplocheilus mirabilis, Allman). This is 



