BY E. J. GODDAKD. 493 



ovate appearance, some more elongate and approaching an ellipse, 

 but slightly flattened on one side parallel to the longer axis, 

 and then again some of an elongate but ovate nature. These can 

 be seen in figs. 7-11. 



In Allman's Monograph the statoblasts have a distinct bean- 

 shaped appearance, but specimens obtained in Europe and North 

 America evidently have shown that these structures may be 

 elliptical in form. Considering the great number of specimens 

 examined and the limits of variation as regards shape in the well 

 known species, the Australian species is quite distinct. 



The animals were killed in a good state of extension by adding 

 a dilute solution of formalin, about 2 %, gradually to the water, 

 and the preservation was found to be good. For some reason 

 the difficulty usually encountered in the cutting of chitinous 

 structures was not met with in the sectioning of the organism, 

 although no softening agent for chitin was used. The material 

 was allowed to remain in molten hard paraffin (58°) over the 

 bath for about one hour after passing through the various stages 

 of embedding by the benzole method, and this probably facilitated 

 the sectioning of the chitinous ectocyst. The method acted 

 admirably for all the sections. Delafeld's hoematoxylin was used 

 for staining entire specimens, and was found to give much better 

 detailed results than borax-carmine. The same stain was used 

 for sections, with eosin as a counter stain. 



I am indebted to Dr. Stokes, Medical Officer to the Board of 

 Water Supply, for the following notes on the occurrence and 

 habit of the species in connection with the water-supply reservoirs. 

 He says — " It is found to grow luxuriously in the screening tank 

 at Pott's Hill, near Rook wood, and also in the 72-inch main from 

 the end of the lower canal to Pott's Hill. In the latter it is 

 most abundant near the inlet into the pipe, forming dependent 

 masses from the crown, as long as 18 inches. These resemble 

 tangled locks of coarse brownish hair. I have not observed it in 

 the open canal, although I am told it is found occasionally in 

 such, beneath the shade of bridges and culverts. I have met 

 with small pieces in water immediately leaving Prospect Reser- 



