38 Rev. T. Hincks on the 



Menipea comjjacta, n. sp., form triplex. 

 (PI. IX. fig. 8.) 



[Described on page 3 of the Report.] 



Only a small and imperfectly developed example of tins 

 species occm-s amongst Dr. Dawson's dredgings ; but very 

 fine specimens from California (where it seems to be ex- 

 tremely abmidant) and Vancouver Island enable me to cor- 

 rect my description of it in one or two particulars. 



I find that on the same colony internodes composed of three 

 cells are mingled with others bearing five or six, so that it is 

 incorrect to designate the triple condition as a distinct form. 

 We have a similar variation in Menii^ea ternata. The oper- 

 culum is not " acicular," as described, in its fully developed 

 state, though always very moderate in size. It is usually, in 

 its perfect condition, clavatc, expanding slightly above. 



M. compacta grows in luxuriant bushy tufts, which bristle 

 with spines. 



Family Cellariidse. 

 CeUaria mandibulata^ n. sp. (PI. IX. fig. 7.) 



[See page 6.] 



The figures represent the avicularium, which exhibits pro- 

 bably the least specialized form of the appendage in the Cel- 

 larian series, and a shoot of the natural size, in which there 

 is a curious departure from the usual dichotomous ramifica- 

 tion. The brandies are given ofi" from the stem at intervals 

 on each side, instead of forming a fork at the joints. This 

 peculiarity, however, does not appear to be characteristic of 

 the species. 



Family Membraniporidae. 



Meynbranipora velata, Hincks. 



This Californian species occurs on shells dredged ofi^ Cum- 

 shewa ; but the specimens from the Queen Charlotte Islands 

 are destitute of the large avicularia. (See ' Annals ' for 

 August 1881, p. 130.) 



Memhranipora acifera^ MacGillivray, form multispinata. 



[See page 8.] 



In a previous portion of this Report I have referred a 

 Memhranipora from the Queen Charlotte Islands to the M. 

 acifera of MacGillivray^, of which it seemed to me to be a 



* Described and figured in a paper read before the Royal Society of 

 Victoria, December 9, 1881 . 



