280 " ENDEAVOUR " SCIENTIFIC RESULTS. 



opercular structure should be so placed ; for although the 

 alternate arrangement of the hydrothecse is insisted on by 

 some, it can scarcely be maintained that a species possessing 

 the other characters should be excluded simply because the 

 liydrothecse are not alternate. 



The species in this collection may be accordingly divided 

 into two main groups : the typical Sertularellce, in which each 

 internode supports one hydrotheca, and the species above- 

 named, with numerous hydrothecae on an internode ; S. 

 divaricata, in some of its forms, is distinctly intermediate. If 

 Levinsen's grouping be strictly followed Dictyocladium dicho- 

 tomum will represent a third section. 



Sertularella gaudichaudi {Lamouroux). 



Sertularia gaudichaudi, Lamouroux, Quoy et Gaimard, p. 

 615, pi. xc, figs. 4, 5. 



? Sertularia picta, Meyen, Nov. Act. Leop.-Car. Acad., xvi., 

 Suppl. i., 1834, p. 201, pi. xxxiv., figs. 1-3. Id., Hart- 

 laub., Abh. Nat. Ver. Hamb., xvi., 1900, p. 77, pi. 

 v., fig. 14, pi. vi., figs. 17, 18, 20. 



Sertularella polyzonias. Bale, Cat. Austr. Hydr. Zooph., 

 1884, p. 104, pi. iii., fig. 1, pi. xix., fig. 25; Id., Bale, 

 Proc.Linn. Soc. N.S. Wales, (2), iii., 1888, p. 763. Id., 

 Warren, Ann. Natal Govt. Mus., i., 1908, p. 291, fig. 

 5 A, B, pi. Ixvii., figs. 18-20. Id., Stechow, Zool. 

 Jahrb., xxxii., 1912, p. 358. 



Sertularia laxa, Allman, Rep. Sci. Results " Challenger " 

 Exped., Zool., xxiii., 1888, Hydroida, pt. II., p. 55, 

 pi. xxvi., fig. 2, 2a. Id., Pictet et Bedot, Res. camp, 

 scient. Prince de Monaco, fasc. xviii., 1900, p. 22. 



Sertularella mediterranea, Hartlaub, Abh. Nat. Ver. Hamb., 

 xvi., 1900, pp. 86, 47, fig. 22, pi. v., figs. 10, 11, 15, 16. 



Sertularia polyzonias (in part), Vanhoffen, Deutsche Siid- 

 polar-Exp. 1901-1903, xi., Zool. iii., 1911, p. 322, 

 fig. 39. 



Sertularella gaudichaudi, Billard, Ann. Sci. Nat., Zool, (9), 

 ix., 1909, p. 317, fig. 5 ; Id., Billard, Ann. Sci. Nat., 

 Zool., (9), xi., 1910, p. 11 ; Id., Billard, Arch. de. Zool. 

 exp. et gen., 51, 1912, p. 464. 



?? Not Sertularella polyzonias (Linne). 



The relations between Sertularella mediterranea, Hartlaub 

 (which Billard finds to be identical with Sertularia 

 gaudichaudi, Lamouroux) and S. polyzonias are greatly in 



