10 Proceedings of the Royal Society of Victoria. 



Lower Tertiary. 



Half a mile below the viaduct, on the left bank of the 

 stream occurs a section which is noted as fossiliferous in the 

 geological quarter-sheet. This section is marked (9) on the 

 l)lan. Lately a small road cutting along its base has afforded 

 easy means ot" better examination of the beds. The section 

 is fairly typical of all that occur in the valley. Tlie lower 

 portion consists of a dark grey clay, containing a great deal 

 of shelly matter. This becomes yellower as it passes upwards, 

 and contains a slight admixture of sand. Concretionary 

 masses of calcareous material make their appearance, and in 

 places form compact irregular bands. Fossils, especially 

 gastropods, are more plentiful at the base of the series, 

 while in the upper part lamellibranchs, and also brachiopods 

 occur, the gasti'opods being exceedingly rare. We record 

 122 species from this locality. 



There is no doubt that the deposit represents but one 

 series of beds. The passage from one kind of sediment to 

 another is a giudual and not a sudden one. The beds merge 

 into one anotiier in such a way as to leave but little doubt 

 that the process of sedimentation was continuous, and 

 though certain fossils abound more in certain parts than in 

 others, the ditference is due to a variation in the sea bottom, 

 due to different material being deposited, and to the depth 

 at which tiie deposit took place, and not to a great difference 

 in age, as the lamellibranchs and brachiopods of the upper 

 beds occur also in the lower members of the series. 



Near the Dog-rocks, the polyzoal limestone makes its 

 appearance, and in one or two places forms low cliffs on the 

 river bank. The beds when examined at a distance show a 

 slight dip, which is approximately to the south east. We 

 were, however, unable to measure its amount and diiection 

 accurately. The lowest beds exposed ai'e at the up[)er 

 ([uarry (see plan 8). The rock here is almost entirely made 

 up of foraminifera, which lie at all inclinations to the bedding 

 [)lane. A sample of the I'ock was forwarded to Professor 

 Tate, and by him submitted to Mr. W. Howchin. This 

 gentleman states that the great mass of the rock is made up 

 of individuals of Orbitoides mantelli, and he suggests the 

 name Orbitoides lini&stone for the formation. The other 

 conspicuous genera, which however are relatively few in 

 number, are Ainphiste(jiaa, Opercidina, and Gypsina. The 

 i-ock is very friable and is quite distinct from the overlying 



