426 Mr. C. Lap worth on the Geological 



Dicellograptus sextans, Hall. Diplograptus foliaceus, Murch. 



divaricatus, Hall. mucronatus, Hall. 



Clathrograptus Geinitzianus, Hall. angustifolius, Hall. 



Diplograptus marcidus, Hall. Glossograptus spmulosus, Hall. 

 Wbitfieldi, Hull. Cliaiacograptus bicornis, Hall. 



Of these species the following occur in similar beds in the 

 valley of the St. Lawrence, Canada* : — 



Diplograptus foliaceus, Murch. Dicellograptus sextans, Hall. 



Climacograptus bicornis, Hull. divaricatus, Hull. 



Dicranograptus ramosus, Hall. Ccenograptus gracilis ?, Hall. 



From the enigmatical Taconic shales of the valley of the 

 Hudson, Dr. Emmons collected a few of the same forms f, 

 viz. : — 



Ccenograptus gracilis, Hall. Didymograptus, sp. 



Glossograptus eiliatus, Emm. 



and from shales in Augusta County, Virginia, possibly of 

 the same geological age, Dicranograptus ramosus. Hall, and 

 several other species of Graptolites of the Norman's-Kiln 

 type. A few like forms are also quoted by him from the shales 

 of Parrotsville, Tennessee, which are apparently upon a 

 similar geological horizon. 



The only Graptolite hitherto quoted from the true Trenton 

 Limestone is Diplograptus amplexicaule, Hall J. The over- 

 lying Utica Slate affords at Oxtumgo Creek, Fort Plain, New 

 York, the following species § : — 



Didymograptus serratulus ?, Hall. Climacograptus bicornis, Hall. 

 Diplograptus foliaceus, Murch. Dicranograptus ramosus, Hall. 



From strata overlying the Trenton Limestone of Nevada, 

 Dr. Charles White enumerates || 



Dicranograptus ramosus, Hall. Diplograptus quadrimucronatus, 



Diplograptus hypniformis, White. Hall. 



foliaceus, Murch. 



Australia. — A few forms of this Llandeilo-Bala fauna are 

 enumerated by Professor M'Coy from the so-called Llandeilo 

 Flags of Australia. The forms that may possibly belong to 

 this general horizon are ^f 



* Hall, 20th Report State Cabinet, New York, p. 221. 

 t Emmons, 'American Geology,' vol. i. pp. 104, 110. 

 \ Hall, Pal. New York, vol. i. p. 79. 

 § WbitHeld, Report lOOtb Meridian, vol. iv. p. 10. 

 || Dr. C. White, Report West 100th Meridian, vol. ii. Paloeontolo°-v, 

 p. 9. 



% M'Coy, 'Prodromus Palaeontology of Victoria,' decade ii, pi. xx. &c. 



