NO. 1171. HYDBOIDA FROM A LASKA AND P UGET SO UXD—XUTTIXG. 751 



and peripheral tubes of Lafo'ea. (Shown between a. t. and^, t., Plate 

 LXIY, lig. 1.) 



Second. There are direct connections between the sarcodal contents 

 of the peripheral tubes of Lafoca and the modified hydrothecte of 

 Coppinia. (Shown between p. V. and m. h'., Plate LXIV, tig. 1.) 



Tliird. There are indirect connections between the perii)heral tubes 

 of Lafo'ea and the luodilied hydrothecie of Coppinia tlirough the media- 

 tion of the mass of tubes of Coppinia which surround the tubes of 

 Lafom. (P. t". to w. /</'., through t. />., Phite LXIV, fig. 1.) 



Fourth. There is a direct cross connection of sarcode between the 

 axial tubes of Lafo'ea and the gonangia of Coppinia directs through (in 

 a horizontal plane) the axial tube of Lafo'ea. (Plate LXIV, tig. 2.) 



Fifth. There is an indirect connection of sarcode between the 

 peripheral tubes of Jjafo'ea and the gonangia of Coppinia through 

 the mediation of the network of tubes of Coppinia surrounding the 

 fascicled stem of Lafoea. (Shown in Plate LXIV, fig. 1, between g', 

 th', imd p. t".) 



My sections therefore comi^letely demonstrate that the gonangia of 

 Goppinia are nothing more nor less than the gonangia of Lafo'ea dumosa, 

 and that the hydrotheca? of Coppinia are simply modified hydrothectB 

 of Lafo'ea dumosa. Further than this, normal hydrothecic containing 

 normal hydranths of Lafo'ea are sometimes interspersed among the 

 gonangia. (Plate LXIV, fig, l/<.) 



A still further discovery, however, was made through the study of 

 these sections. A careful examination showed that interspersed among 

 the female gonangia containing ova were male gonangia containing 

 sperinaries in which were mature spermatozoa. (Plate LXIV, figs. 

 Is, 4.) 



The male gonangia were much more slender than the female and 

 very much less numerous, the proportion of male to female being about 

 one to twenty. The only contents that could be made out in each male 

 gonangium was a long saclike sperosac or spermary containing ma- 

 ture spermatozoa. 



Bisexual colonies are rare among the hydroida,' and, so far as the 

 present writer knows, have not hitherto been found in campauularian 

 forms. 



The large, strongly modified hydrothecre do not show the character- 

 istic liydranths of Coppinia in the part of the specimen included by the 

 sections examined, but are closed at the end and show no indication of 

 tentacles. Further up on the stem these structures intergrade with 

 other hydrotheca?, which are open at the end and contain hydranths 

 with tentacles, such as those usually described as pertaining to Coppinia. 



' Allman says (Monograph of the Gymnoblastic or Tubularian Hydroids, Ray So- 

 ciety, 1870, 1871, 1872, p. 148), "As an ahnost universal rule, then, the Hydroida are 

 diojcious; in other words, every colony is unisexual." The only exceptions men- 

 tioned by this author are Hydra, Plumularia pinnata, and Dicoryne conferta. 



