Victorian Graj^tolifes. 109' 



l.ocaliti/. — -(^tuari'v in hard l>lue slate, one mile west of school on 

 road from Woodend to Macedon ; in similar rock Steiglitz District 

 (Min. Dept.). 



Associates. — Goniof/rapfKs spp., 0/icor/rapfiis npsiloii, D . 

 caducens (large typical variety), I), forcijyiformis, etc. 



Horizon. — Castlemainian. 



Oncogkaptus n. gen. 



Hydrosome at first biserial, but later dividing into two uniserial 

 branches. Thecae long, 'narrow and slightly curved. 



The form of the genus is quite different from that of any other 

 graptolite. The form of the thecae and tlie great width of the 

 branches seem to remove it from the Dicranograptidae. 



As regards its origin it may be pointed out that it resembles 

 D. caduceus in the form of its thecae. Concrescence of the branches 

 of this species for a certain distance would produce a somewhat 

 similar form. The thecae of the uniserial part appear to be 

 opposite, and not alternate, but though I have had a very large 

 number of specimens before me, none show the details of structure 

 very clearly, and I have waited in vain for a long time for better 

 material. 



Oncograptus upsilon, n, sp. (Pi. XVII., Fig. 14). 



Uniserial portion about 12 mm. long. Breadth at level of 

 bifurcation 10 or 12 mm. Width of uniserial branch about 6 mm. 

 Length of branch 10 mm. These are the dimensions of the type. 

 but the measurements vary a good deal in other specimens. The 

 whole polypary has the form of an aiiowliead. 



Thecae 9 in 1 cm. Near the proximal end of the hydrosome 

 they are at right angles to the axis, and probably at the proximal 

 end itself have turned through an angle of 90°, and are in a line 

 with the axis of the undivided portion. At the distal end of the 

 uniserial branches they are inclined at about 30o. The apertures 

 are trumpet shaped, and a long recurved denticle is present. The 

 sicula has not been seen. The axil seems united by a membrane. 



0. upsilon is the type of the genus. 



Locality. — Frederick the Great Mine, Sebastian (Type). Quarries 

 north and west of Gisborne; Steiglitz; Castlemaine (Harri.s) ; 

 Yapeen (Ba. 90, Quartersheet 15 N.E.), in National Museum, pro- 

 bably collected by Ulrich in 1864; Ingliston (quarry near 42,i mile 

 viaduct on railway. A. E. Kitson). • 



Horizon. — Castlemainian, but exact position uncertain. 



