the Lower Silurian Rocks of Victoria. 9 



pristis ?, Hisinger ; Graptolithus latus, M'Coy ; Graptolithus, 

 sp. (? G. tenuis , Portlock). 



Castlemaine : Tetragraptus bryonoides, Hall ; Didymograp- 

 tus (?) fruticosus, Hall ; D. nitidus, Hall. 



Redesdale (Spring Plains) : Tetragraptus bryonoides, Hall ; 

 Loganograptus Logani, Hall ; Didymograptus Pantoni ?, M'Coy. 



Further Note on the Structure of Ceratiocaris. 



At the Brighton Meeting of the British Association* Mr. 

 H. Woodward, F.R.S., noticed the discovery of the " swim- 

 ming-gills " of Ceratiocaris, to which I had previously drawn 

 his attention. On a slab of thin flaggy shale from the 

 Upper Silurian series of Lesmahagow are exposed the caudal 

 segments, telson, and caudal appendages of a Ceratiocaris. 

 From the ventral margin of the terminal segment proceeds a 

 broad paddle-shaped membranous (?) expansion, presenting a 

 strong marginal outline, with a transversely striated surface. 

 This is followed by another similar appendage, proceeding in 

 the same manner from the penultimate segment. The dorsal 

 edge of the specimen shows that one of the corresponding 

 " foot-gills " of the opposite side has been bent back upon 

 itself, and thus thrust out of place. The free ends of these 

 paddle-shaped appendages are attenuated to more or less 

 rounded points. They do not show any evidence of a mar- 

 ginal fringe. These gill-feet are no doubt analogous to the 

 same supplementary abdominal organs in Nebalia. 



Locality. Linn Burn, about two miles north of Muirkirk, 

 Lanarkshire, in thin flaggy shale. Collection of the Geolo- 

 gical Survey of Scotland. Collected by Mr. A. Macconochie. 



EXPLANATION OF PLATE III. 



Figs. 1 & 2. Tetragraptus bryonoides, Hall. Spring Plains, Redesdale, 

 Victoria. 



Figs. 3 & 4. Tetragraptus bryonoides, Hall (D. caduceus, Salter). Watch- 

 box Ranges, near Baynton's, county of Dalhousie, Victoria. 



Fig. 5. Tetragraptus quadribrachiatus, Hall. Watchbox Ranges, near 

 Baynton's. 



Figs. 6-8. Tetragraptus quadribrachiatus, Hall. Newhain, near Lance- 

 field, county of Bourke, Victoria. 



Figs. 9 & 10. Phyllograptus typus, Hall. Newbam, near Lancefield. 



Fig. 11. Loganograptus Logani, Hall. Spring Plains, Redesdale, Victoria. 



Fig. 12. Loganograptus Logani?, Hall. Newham, near Lancefield. 



Fig. 13. Climacograptus ?, sp. Newham, near Lancefield. 



Figs. 14 & 15. Diplograptus mucrcmatus, Hall. Watchbox Ranges, near 

 Baynton's, county of Dalhousie. 



* Brit. Assoc. Report, 1872, p. 323 ; also Mem. Geol. Survey, Explana- 

 tion 23. Scotland, p. 93. 



