64 



ON THE CHAEACTEES OF THE GEIfTJS LOPHOPUS. 



wide, mainly composed of a large nucleus, whicli contains a 

 nucleolus, itself about *002 millim. broad. 



These cells are not described by Allman {loc. cit.) or in Hyatt's 

 papers (Proc. Essex Institute, vols. iv. & vi.), nor bave I seen tbem 

 noticed in any otlier paper which I have met witb. Their form 

 would seem to assign a mesodermic origin to them, but bitberto 

 no overlying tissue has been found, to represent the ectoderm. 



Floating Apparatus of the Statohlast. — The cellular structure 

 of the annulus of tbe statoblast in those forms in whicb it is 

 developed resembles tbat of the gemmule of true SpongillidcB, 

 as elucidated by the researches of Carter, Marshall, and Vej- 

 dowsky, so strongly that it only requires to be pointed out in 

 order to be recognized. 



Australasian Species of Freshwater Folyzoa. 

 Tbe only Australasian species of Freshwater Polyzoa recorded 

 by Jullien {I. c), and by Hutton, in his ' Catalogue of the Marine 

 MoUusca of New Zealand,' is Flumatella Aplini of Macgillivray. 

 A form assigned to Flumatella repens, var. a of Allman, is, however, 

 described by A. Hamilton from near Napier in New Zealand 

 (Trans. New Zeal. Inst. xii. p. 302) ; and Mr. "Whitelegge is stated 

 to bave exhibited the same species, Flumatella repens, and Frede- 

 ricella sultana, from New South Wales, in Proc. Linn. Soc. N. S. 

 Wales, viii. (1883) pp. 297, 416. The genus Lophopus does not 

 appear to have been hitherto recorded from Australasia. 



DESCRIPTION OF PLATE II. 



Fig. 1. Lophopus Lendenfeldi, n. sp. Part of the colony, attached to plant- 

 stem, showing a subspiral arrangement of the zoarium. Natural size. 



2. Part of the zoarium, showing zooids in different states of contraction 



or expansion, a. Hyaline (? cuticular) layer observed at termination 

 of body of polypides. b. Food-mass in alimentary canal. X 40 diam. 



3. Portion of the ectocyst, to show structure as exhibited by staining with 



borax carmine, a. Stellate cells ; b. Globose cells. X 600 diam. 



4. A statoblast, showing: a, annulus; b, body; c, blastodermic cells*? 



X 60 diam. 



N.B. These figures are somewhat schematized, except as regards essejitial 

 details. 



* These bodies appear to consist mainly of refractive granules and of a 

 large nucleus. Perhaps they represent an early stage in the division of the 

 germ-cell. 



