Tlie Geology of CoDnaldal. 203 



2. Cockatoo Gully, above Coimaidai. 



Didymograptiis exfensiis, J. Hall ; D. caduceus, Salter ; Tetra- 

 graptus of quadrihrachiatus^ J. Hall; Phyllograptus ? angitstifolms, 

 J. Hall. 



The specimens are as a rule badly preserved. The specimens 

 of D. caduceus are common and very large, as is usual in the 

 higher zones at Castlemaine. There are also present fragments 

 of a large species of .? Didymograpttis. Its branch has a very 

 slight sigmoidal curvature, but though I have many fragments 

 from several horizons at Castlemaine I am uncertain of its 

 generic position. As all the species, even those provisionally 

 identified, have a considerable range in the Lower Ordovician 

 the exact horizon is uncertain. 



3. Back Creek, Coimaidai. 



The only species obtained was D. caduceus, of which sevei'al 

 examples were obtained, one gigantic specimen measured 7 "5 cm. 

 in length and is far the largest I have seen. The specimens 

 came from a loose block, but Mr. Officer thinks it had not 

 travelled far. 



4. Deep Creek, near Melton. 



The specimens came from an outcrop just below the bridge 

 liy which the Melton to Bacchus March road crosses the creek. 



Didyiuograptiis caduceus, Salter ; Tetragraptus serra, Brong ; 

 Dichograptus ? n. sp., Phyllograptus typus ? J. Hall; Diplograptus 

 sp., Lingulocaris maccoyi, Eth., jr. 



The slates are much decomposed but are very rich. The 

 Dichograptus resembles a species occurring in the " Didymo- 

 graptus caduceus zone " at Castlemaine, and appears to be 

 new. The Diplograptus is very abundant but indecipherable. 

 The zoological position of forms very like our Lingulocaris 

 seems uncertain, for Gurley^ considers it a graptolite and not 

 a crustacean. The horizon is probably near the D. caduceus 

 zone, probably somewhat higher as Diplograptus is so abundant. 



1 Jounuil of Geology, vol. 4. pp. So, et. »eq. 



