14 "endeavour'-' scientific results. 



While these sheets are passing through the press, however, I 

 have been favored by Professor Levinsen with a copy of his 

 important paper, just issued, entitled " Systematic Studies on the 

 Sertulariidae." In this work he re-states and elaborates his 

 views as to the primary importance of the operculum in classifica- 

 tion, and insists that the mere arrangement of the hydrothecae is 

 of no generic value whatever. This paper demands the most 

 careful study, and, if its author's conclusions are vindicated, will 

 result in the complete breaking-down of the old generic boundaries 

 and a drastic re-arrangement which, while retaining the old 

 names, will employ them in a sense having no relation to their 

 former meaning. Meanwhile, so long as we continue to accord 

 primary importance to the growth-characters, I think we should 

 do so consistently, hence my objection for example to the 

 reference of Thuiaria lata to Sertularella. If Levinsen's views 

 be adopted that reference will undoubtedly be correct, but if a 

 systematist accepts (as the majority do) the arrangement of the 

 hydrotheca? as his principal criterion in discriminating between 

 Sertularia, Thuiaria, Selaginopsis, etc., I cannot see why the 

 same principle should not apply to the case in point. 



I may add that in Levinsen's system <S'. macrocarpa, 

 S. maplestonei, and similar species are referred to a new genus — 

 Odontotheca. 



Sertut.akia mackocaupa, Bale. 



Sertularia macrocarpa, Bale, Cat. Austr. Hyd. Zooph., 1884, 

 p. 80, pi. v., fig. 2, pi. xix., fig. 11 ; Marktanner- 

 Turneretscher, Ann. k.k. naturhist. Hofmuseums Wien, 

 v., 1890, p. 232; Jaderholm, Bihang k. svenska vet.-akad. 

 Handlingar, 21, 1896, p. 13; Schneider, Zoolog. Jahrb., x., 

 1897, p. 523 ; Calkins, Proc. Boston Soc. Nat, Hist., xxviii., 

 1899, p. 359. 



Two varieties of this species were noted. In the first, which 

 is similar to the original type, the hydrotheca? have their upper 

 side at right angles with the hydrocaulus only on the proximal 

 portions of the pinna?, but elsewhere they are distinctly ascend- 

 ing, this character becoming moi'e and more pronounced as they 

 approach the distal extremity of the pinna, where they are 

 almost tubular, and directed upward as much as outward. 

 Beyond the last pair the hydrocaulus is commonly continued 

 into a long tubular prolongation, often of three or four internodes, 

 bearing in some cases one or two hydrothecae, often more or less 

 deformed, but mostly without any. The pinna-internodes each 

 support a single pair of hydrotheca?. The other variety has the 

 stem-internodes longer, the pinnae comprising internodes bearing 

 each two pairs of hydrothecae, which may persist throughout, or 



