THE VICTORIAN NATURALIST. 161 



now decomposed, the nodular structure of which is here and 

 there still perceptible. This material continued to the eastern 

 end of the cutting. Crossing the paddocks in a north-easterly 

 direction, the creek was soon reached, where we immediately 

 came upon recent ferruginous sandstones in the sides of the 

 creek, closely simulating in some respects those we had just left, 

 which were of Tertiary age. 



The creek for some distance has eroded its course down into 

 the Upper Silurian rocks, and along its windings these were 

 continued till we reached the cliff. One of the first features to 

 attract attention here were the "ripple markings" on some of 

 the thicker of the sandstone beds. The fact as to whether these 

 markings were really ripple marks had been disputed, and the 

 evidences for and against were discussed with much interest, the 

 unanimous verdict being finally in favour of their being such. 

 Descending a few yards lower down the creek, by the cliff, a 

 diligent search was made for examples of the fossils for which 

 these rocks are famous, and numerous specimens were collected. 



The next point to receive attention was the decomposed 

 " Elvan " dyke, and the disturbance in adjacent rocks was 

 noted. Ascending the steep bank to the roadway immediately 

 above the dyke and a few yards to the north of its appearance 

 in the road cutting, a small anticlinal fold was observed in the 

 Silurian rocks. From here the road was followed northwards 

 into the cutting at the western end of Union-street, Brunswick. 

 Almost immediately above the cliff Tertiary deposits were again 

 met with, crowning the summit of the hill of Silurian rocks in 

 that locality, and were seen to rest directly on them, its uncon- 

 formability with the Silurian being distinct. Expressions of 

 satisfaction at the afternoon's observations were exchanged, and 

 the party dispersed. 



Among the specimens obtained from the Tertiary grits were 

 the following : — Plant remains — Ancillaria, Peristerina, Haliotis, 

 Mactra, Leda ; and from the Upper Silurian rocks — Orthoceras 

 ibex, Rhynchonella decemplicata, Trematospira, Orthis. — Geo. 

 Sweet. 



PRELIMINARY DESCRIPTION OF A NEW SPECIES 



OF APUS. 



By Professor Baldwin Spencer and T. S. Hall, M.A. 



The following is a brief description of a new species of the genus 

 Apus — the first which has as yet been described from Australia. 

 Apus australiensin, sp. n. 



Carapace a short oval. Its length about equal to the length 

 of the portion of the abdomen which is not covered by the 

 carapace, though this is liable to considerable variation. 



