56 C. McLEAN FBASEE 



as his reason for adopting this method, that these groups "dis- 

 courage the groAvth of synonyms, offer no awkward bars to the 

 free passage of any species from one group to nearer relatives". 

 He evidently is consistent with this statement, as he uses the 

 same generic name, Sertularia, in two different groups, while in 

 the same paper,^^ he uses the two generic names, Dynamena and 

 Sertularia, for two species almost as much allied as it is possible 

 to find. 



It seems to me that it is a fair test of classification into genera, 

 if one who has examined a good supply of material, which has 

 included species of the allied genera of a group, can take a typ- 

 ical form that he has not already seen and without hesitation, 

 place it in the genus in which it belongs^ without necessarily go- 

 ing over all the points of distinction. This test will apply to 

 these 7 genera of the SertularidcB, consequently, they may be ac- 

 cepted as satisfactory. This by no means excludes the possibility 

 of intergrading forms, as these are found here as well as else- 

 where. This is particularly true among the lower marine forms. 



Of the other 5 genera, Dictyocladium, Pasythea, Staurotheca, 

 Synthecium and Thecocladium, only two, Dictyocladium and 

 Synthecium, are reported from this Coast. As far as the genus 

 Dictyocladium is concerned, I have seen no exception to it ex- 

 cept from Billard,''^ who would place it with Selaginopsis, but as 

 he gives no indication that he has seen any specimen that would 

 be included under this genus, the features of the genus which 

 Allman^^ and Nutting^'-' point out would, necessarily, not come 

 under his observation. 



To the genus Synthecium Torrey takes great exception, in both 

 Hydroid papers, but especially the latter. He claims that the 

 species*° described by Nutting as Synthecium cylindricum, 

 should be considered a Sertularella, which he calls S. halecina. 

 His argument is this. In his material he has found specimens, 

 some of which have gonangia springing from the hydrothecse, as 

 is required for Synthecium, but he has also found them extra- 



36 Hydroids of San Diego, 1904. 



37 Hydroides du Travailleur et du Talisman, 1907, p. 183. 



38 Challenger Report, The Hydroida, Part II, 1888, p. 76. 



39 American Hydroids, Part II, 1904, p. 105. 



40 Hydroids of San Diego, 1904, p. 21. 



