158 On a Deposit of Diatomacea at South Yarra. 



Art. IX. — On a Deposit of Diatomaceie at South Yarra. By 

 John Coates^ M.ll.C.S.L'_, South Yarra. 



[Read before the Koyal Society of Victoria, October Sth, 18G0.] 



At the last meeting of the Eoyal Society, some mieroscopic 

 organisms were exhibited by my friend, Mr. Ralph, from the 

 mud of a swamp near the Yarra, "where the IMelbourne and 

 Sul)urban Raihvay crosses that river. During the interval 

 that has intervened, this deposit has been the subject of more 

 careful and extensive examination, and in the results which 

 I have the honor to submit to your inspection this evening, 

 it will be shown that in the locality of South Yarra there is 

 a vast and interesting field of infusorial remains, containing a 

 numerous variety of microscopic objects, not less remarkable 

 for their exquisite beauty and delicacy of structure, than for 

 the extreme profusion in which they are to be found. These 

 remains are generally silicious, and the extraordinary preser- 

 A^ation which they exhibit is due to this circumstance. 



On the southern bank of the river Yarra, where the railway 

 operations are in progress, an embankment has had to l)e 

 carried across a small swamp to the bridge now in course of 

 erection. This swamp has its termination in the Yarra, at a 

 short distance to the Avestward of the line of raihvay, 'and 

 extends in a south-easterly direction beyond the Gardiner's 

 Creek Road, serving as an outlet to the watershed of a large 

 portion of the municipal district of Prahran. As the material 

 to form the embankment alluded to was thrown upon the 

 surface of the swamp, the weight of the super-incumbent 

 earth, assisted by occasional heavy rains, burst up the soft 

 and spongy matter of the bog, and totally obstructed the 

 drainage, to which a reference has just been made. In order 

 to provide a remedy, the Railway Company have been 

 necessitated to dig up this boggy earth, preparatory to the 

 formation of a permanent outlet to the river ; and in the 

 material thus removed have been found those microscopic 

 and other organisms which are now brought under the 

 cognizance of the Society. Several specimens of the deposit 

 are placed upon the table this evening. In some of these, 

 marine shells, more or less perfect, pieces of cuttle-fish bone. 



