122 Rev. T. Ilincks's Contributions towards a 



fessedly our present knowledge does not allow of a complete 

 natural arrangement, it may be wiser to rest on the old lines 

 and retain for the present the artificial system so long in use. 

 From this view I must entirely and earnestly dissent. I 

 hold that itis all but demonstrated thatzooecial, and not zoarial, 

 characters must be the basis of a natural classification of the 

 liighcr Polyzoa. And if this be so, it is surely in every way 

 better to apply this principle as far and as well as our present 

 knowledge will permit, and allow -it to give the direction to 

 further investigation ^i\\n\\ to perpetuate a system which, how- 

 ever convenient to the collector in the arrangement of his 

 cabinet, gives Kim no help towards understanding the order 

 of nature. Let us set our faces in the right direction, and 

 while admitting freely the extent of our ignorance, make full 

 use of the knowledge which we have. 



The Radical Tubes. — The erect stems of Steganojiorella Neo- 

 zelanica are attached by tubular fibres ; and in this respect it 

 differs from its congeners. The difference, however, can 

 hardly be accounted important. The fibres are a tubular ex- 

 tension of the membrane which covers the front of the cell, 

 and seem only to originate from the zooecia close to tlie base 

 of the stem. In the (so-called) Flustra solida, Stimpson, the 

 curious fibres which traverse the surface of the zoarium, 

 uniting to form a kind of stem below, from which the radical 

 fibrils are given off, originate in the same way from an epi- 

 dermal covering of the cells. In the Microporidan Vincidaria 

 abyssicola * Smitt figures the cylindrical stem as continuous 

 with the incrusting hiyer of cells from which it rises, and of 

 course destitute of root-fibres. The stems of the present 

 species probably rise in the same way from an incrusting 

 layer; and if so, the tubes may be developed at a later stage, 

 in preparation for the ultimate detachment of the stem from the 

 adherent mass of cells. 



Ooecium. — The very large size of the upper chamber in this 

 form and the kindred S. magnilabris^ in a certain number of 

 the cells, suggests at once that it is the equivalent of the 

 ooecium. If so, the modification is a very interesting one. The 

 dithalamic condition is made subservient to the reproductive 

 function ; in certain of the cells the upper compartment is 

 largely increased in size, and in tliis specialized form is no 



* In a note on 7'. ahjssicola {' Annals,' February 1881) I have stated 

 that tills species and V. ornata, Busk, are true " Membranoporldcie." 

 This Is an error. The latter Is a Memtjranipora, the former a Steyanopo- 

 7'dla, and belongs to the Mlcroporldae. 



In the same note the second sentence should read thus : — " I mention 

 this to show how essentially Mici-oporidan [not Memhranijwridan, as 

 printed] the zooecial character of this form is." 



