544 Progress in Science. [Oftober, 



form large masses in these limestones, and which are known as Stromatopora, 

 are mostly of this nature, although fossils of the nature of corals have been 

 included with them. In the Upper Silurian (or Silurian proper) are similar 

 if not identical forms known as Ccenostroma, with a skeleton consisting of a 

 series of calcareous layers connected with each other by pillars or wall-like 

 processes; while in the Devonian masses of limestone, sometimes 12 feet thick 

 are made up of these organisms, which have clearly foraminiferal affinities, 

 and are intermediate between the Eozoon of the Laurentian and the Parkeria 

 and Loftusia of the greensand and eocene. 



Prof. Bianconi has published further information on the bones of ^Epyornis, 

 corroborative of his views of its being an immense vulturine bird, the " Roc" 

 of Marco Polo. 



M. Schmidt, in a note published in the" Geological Magazine," states his 

 opinion that the shields of Pteraspis and Scaphaspis belong to one and the 

 same animal, Scaphaspis representing the ventral shield of Pteraspis. 



Mr. Davidson has described some Brachiopoda collected by Mr. Judd from 

 the Jurassic deposits of the east coast of Scotland. Three of them were 

 obtained from the equivalent of the Kimmeridge Clay, which was the more 

 remarkable as the Brachiopoda of that formation are comparatively few. 



Dr. Gumbel has described to the Bavarian Academy of Sciences the so- 

 called " Nullipores," which he resolves into two kinds : — 1. True calciferous 

 Algae {Lithothamniiun, and an allied form, Lithiotis) ; and 2. Foraminifera 

 (Dactyloporidcce). 



M. Barrande, who is so well known for his researches on the Silurian 

 system of Bohemia, has recently published a supplement to Vol. I. of his 

 great work, on the different Crustacea and Fishes of these old rocks. Of the 

 former he describes ninety-four new species of Trilobites, of the latter indi- 

 cations of four genera have been discovered, namely Astcrolcpis, Coccosteus, 

 Ctenacanthus, and Gompholepis. His observations do not agree with the 

 theory of evolution. He passes in review the different parts of the Trilobites, 

 the succession of their species and genera in time, and institutes a comparison 

 between the fishes, Trilobites, and Cephalopoda, and their relations to the 

 primordial fauna generally. Everywhere he finds that the appearance of new 

 forms is sudden and unaccountable, and that there is no indication of a regular 

 progression by variation. 



The base of the Palaeozoic series in America until lately was formed by the 

 Potsdam sandstone, although lower horizons of life had been determined by 

 Barrande in Bohemia, and Salter and Hicks in Wales. The researches of 

 Mr. Murray in Newfoundland, together with the study of the fossils by Mr. 

 Billings, have revealed a lower Potsdam, while Messrs. Hartt and Matthew, 

 by their explorations of the rich primordial fauna of St. John, have led to the 

 establishment of an " Acadian Group " on the horizon of the lower slate 

 group of Jukes in Newfoundland, of the gold-bearing rocks of Nova Scotia, 

 and of the slates of Braintree in Massachusetts. 



Stratigraphical Geology. — One of the most important papers in British 

 geology which has been published in recent years is that " On the Secondary 

 Rocks of Scotland," by Mr. J. W. Judd, the first part of which has been pub- 

 lished in the "Quarterly Journal of the Geological Society." The Mesozoic 

 periods are in Scotland represented only by a number of isolated patches of 

 strata, situated in the Highlands and Western Isles ; which have been pre- 

 served from the destructive effects of denudation, either through having been 

 let down by great faults among the palaeozoic rocks, or through being sealed 

 up under vast masses of tertiary lavas. These have been unravelled by 

 Mr. Judd, who has depicted their superficial extent upon a coloured geological 

 map which accompanies his paper. The cretaceous rocks, exhibiting very in- 

 teresting characters and yielding a beautiful series of fossils, were discovered 

 by the author on the mainland, and in several of the islands of the west of 

 Scotland. The Jurassic rocks, which were first described by Murchison, are 

 now shown to present a remarkable contrast with their equivalents in England, 



