206 Geoh(jical Society. 



the collection lias been placed in the Geological Department of 

 the University Museum, Oxford. These fossils were forwarded 

 by Prof. W. J. Sollas to Prof. C. Lapworth, who embodied the 

 results of his study in a Report, of which the following is a brief 

 abstract. 



The specimens are recorded as all occurring in the same locality, 

 but it is not known whether they were obtained from a single zone. 

 The majority of the rock-specimens in which the graptolites occur 

 are black and somewhat pyritous carbonaceous shales, usually well 

 bedded and uncleaved, and the graptolites are in general well 

 preserved. The lithology of the containing rocks and the mode of 

 preservation of the graptolites are similar to those obtaining in 

 the richest graptolite-bearing strata of Britain, Europe, and North 

 America. 



The forms apparently represented in the collection are Loffctno- 

 c/raptus logani Hall, a new species of Goniofp'aptus (?)^ Didymo- 

 qrapfus stahilis^ Elles & Wood and D. bifidus Hall, Fliyllograptus 

 anr/uxf/folius Hall, Glossoqraptus acaiithus Elles & Wood, Grypto- 

 graptus tricornis Hall, var., Amplexograptus confertus Lapworth, 

 and A. ccelatus Lapworth. 



Taken as a whole, this graptolite fauna may best be compared 

 with that of the Upper Arenig formation of Britain and its North- 

 American equivalents, answering to the Lower Llanvirnian of 

 Hicks & Marr and the Didymograptus-hifidus Zone of Elles & 

 Wood and H.M. Geological Survey. 



The assemblage of graptolites discovered in Bolivia a few years 

 ago by Dr. J. W. Evans corresponds very closely with this Peruvian 

 fauna, and was probably derived from the southward continuation 

 of the same Andean graptolite-band. The Peruvian forms in the 

 Douglas collection, like those from Bolivia, admit ahiiost as close a 

 parallelism with those of the Arenig-Llandeilo graptolite -beds of 

 Australia and New Zealand as wdth their representatives in the 

 Northern Hemisphere. 



Not only is the Douglas Collection of Peruvian graptolites 

 instructive and valuable from the palseontological point of view, 

 owing to the number and the good state of preservation of the 

 species represented, but it is of especial interest from the palseo- 

 graphical aspect, as affording additional proof of the identity 

 (in general facies) of the graptolite fauna of the sea-waters of 

 Lower Ordovician times in those regions of the globe which are 

 -now occupied by some of the dry lands of Britain, Eastern North 

 America, Peru, Bolivia, Victoria, and New Zealand. Thus it greatlj'- 

 strengthens the inference that in Arenig-Llandeilo times there 

 was open-sea communication admitting of the circulation of sea- 

 ■currents along some as yet undetermined line or lines, connecting 

 the above-mentioned regions, which must have extended across the 

 Equator and apparently throughout a length nearly equal to that 

 of half the circumference of the globe. 



