146 Transactions. 



plausible explanation of the occurrence of the above-described albino 

 duck, I gladly publish it as received : — 



Writing on the 16th August, 1914, Mr. Kempthorne says, " I have just 

 noticed a paragraph on page 9 of Otago Witness of the 12th August about 

 an albino wild duck having been shot. I dare say you will be interested 

 in a very probable explanation of this curiosity. At my mother's place 

 (" Parkdale." Heriot) there is a large pond which for twenty years has 

 been a sanctuary for the wild duck (it being on private property, and my 

 mother's wishes that no shooting shall be allowed, have made, it such). In 

 wet weather hundreds of ducks gather there, and the ducks bred there 

 make it their home. For years there were white tame ducks also, but 

 they dwindled in number until only one drake remained. This drake mated 

 with a wild grey duck that was unable to fly (or could fly very little) and 

 necessarily had to live entirely at the pond. I remember four or five years 

 ago coming on a mixed clutch of ducklings (whites and greys), but after 

 seeing them two or three times I never saw them again, and concluded 

 that a weasel had accounted for them. On a recent visit to " Parkdale " 

 (three weeks ago) I saw an albino wild duck, and my brother said there 

 were more than one. It could fly, as I made it my business to frighten 

 it and see. Evidently the tame white drake and the crippled wild duck 

 had mated again, and their progeny had lived. The distance between 

 Heriot and Mataura in a direct line would be thirty-odd miles, and this 

 would not be an excessive distance for the flight of a wild duck. The tame 

 Indian runner duck and the wild grey duck mate without trouble, but 

 this is the only case I have heard of a white tame duck mating with a wild 

 grey duck. It would be interesting to test the case again on the wild grev 

 ducks in the Botanical Gardens. The two ducks would have to be shut 

 together continuously for a lengthened period to ensure a satisfactorv 

 result."' 



Art. XVII. — On Ascidioclava, a New Genus of Gi/ninoblastic Hydroids. 



By Professor H. B. Kirk, M.A., Victoria University College, Wellington. 



[Bead before the Wellington Philosophical Society, 26th October, 1914.] 



Plate I. 



Characters of the Genus. 

 Trophosome. — A creeping hydrorhiza, branching freely, gives rise to 

 unbranching hydrocauli, each terminating in a hydranth. Hydranths 

 with filiform tentacles not in definite whorls, but tending to be arranged 

 in three or four whorls. Perisarc entirely wanting. 



Gonosome. — Medusa buds produced in clusters near the base of the 

 hydranth, whether becoming free or not at present uncertain ; tentacles 

 rounded. 



Ascidioclava parasitica n. sp. Plate I. 



Height of hydrocaulus and hydranth together, 2-3 mm. Tentacles of 

 adult hydranth, 20 or more in number ; average length of tentacles, 0-4 mm. ; 

 the widest part of the tentacle a little above the base, the tentacle then 

 tapering to the tip, where the diameter is about half that of the widest 

 part. Hydrorhiza branching freely and anastomozing, the branches becoming 

 concrescent, with absorption of ectoderm and mesogloea at the points of 

 contact, giving a continuous coenosarcal sheet. Endoderm of hydrorhizal 



