[fraser] MONOBRACHIUM PARASITUM 137 



it readily from P. goodei} Clark's specimens were in such poor shape 

 that he found no nematophores and hence he placed the species in 

 the genus Halecium. Apparently there were no gonangia present. 

 Nutting, on seeing Clark's description and figures, placed the species 

 in the genus Plumularia. Torrey found a few fragments but on one 

 of these there were some immature gonangia. 



On Sept. 12, just outside of the entrance to Bull Harbor, to the 

 south of Hope island, I found a large number of very fine colonies, 

 growing on Macrocystis. They were growing in bunches of from 16 

 to 20, on both sides of the leaf. The trophosome bears a great re- 

 semblance to that of P. goodei Nutting. In fact the only constant 

 point of difference that I can be sure of, appears in the arrangement 

 of the hydrocladia. In P. goodei the normal number seems to be 2 to 

 a node although 1 or 3 may be present but in P. pliimularoides in 

 every case of the many examined there was a single hydrocladium to 

 each node. These colonies are all longer and more robust than in 

 any specimens of P. goodei that I have seen but as this difference is 

 not very great, it may be due to environment. 



There is no such resemblance in the gonosome. There is a difference 

 in the shape of the gonangia as well as in the arrangement of these. 

 In P. goodei the gonangia take the place of the hydrocladia, in P. 

 plumidaroides they are attached to the hydrocladia, on the hydrothe- 

 cate internodes beside the hydrothecae, or more commonly on the 

 cauline internodal process that supports the hydrocladium. There 

 may be as many as four in a row along one hydrocladium. The 

 gonangia of P. goodei are relatively large with the distal end obtuse, 

 scarcely narrower than any other part of the gonangium while in 

 P. pliimularoides they are oval with a bottle neck and one diameter 

 greater than the other. 



Papers Referred to in the Text 

 bonnevie, k. 



1889. Den Norske Nordhavsexpedition, 1876-78, vol. VI. pt. XXVI. Zoologi 

 Hydroida, p. 1-103. Christiania. 



Broch, H. 



1909. Die Hydroiden der Arktischen Meere. Fauna Arctica, bd. V. Jena. 



Clark, S. F. 



1876. Report of the hydroids on the coast of Alaska and the Aleutian Islands, 

 collected by VV. H. Dall, from 1871 to 1874. Proceedings of the Academy 

 of Natural Sciences of Philadelphia, p. 205-238. Philadelphia. 



^ Hydroids of Vancouver island region, 1914, p. 207, 



Sec. IV , Sig. 10 



