80 



Mi'c G. R. Vine 07i Species of 



shall call the pulp, is sometimes continuous, at other times 

 slightly separated from the adjoining mass, when the grains 

 appear like a row of beads dotting the centre of the threads 

 (figs. I. & II. 3 to 5). Surrounding the pulp are delicate and 

 transparent walls, which are distinct and clearly defined. In a 

 few cases the filament bifurcates and the pulp in the undivided 

 portion separates at the node and passes into the divisions 

 thus formed. Heal development takes place at irregular inter- 

 vals. On the sides of the thread there is a slight protuberance 

 of the wall, which increases in size until a roundish knob or a 

 lagena-like vesicle is formed. Into these vesicles, which may 

 be either single or in groups, the pulpy mass passes ; but to 

 what extent the colony increases beyond the A.-siluriense 

 stage, I am unable to say ; although I believe we may safely 

 regard this species, at least, as the ultimate outcome of the 

 colonial development of A. jiliforme, Vine. 



Fiff. II. 



4, 5. Ascodictyon filiforme (transparent and semi transparent), showing 

 vesicles and pulp. 



6. Ditto, sliowino- clusters of vesicles, passing into 



7. A. silunense, Vine. 



At this stage of inquiry it may be well to ask, whether the 

 name A. silurtense, Vine (Wenlock Polyzoa, oj). cit. p. 52), 

 should be suppressed. If the Silurian name is suppressed 

 the Devonian name [A. stellatum, Nich. & Eth.) must be 

 suppressed also, unless the one name may be allowed to 

 embrace both the type and the varieties. In opposition to this 

 view, I think the wiser course would be to allow the forms to 

 retain their present names as given below, for the simple 

 reason that it would be perhaps impossible, or almost impos- 

 sible, to make another collection similar to my own unless the 



