1887] Geology and Paleontology. 659 
Barrier-reefs, says our authority, always stand upon a conti- 
nental border composed of rock fragments, and the want of such 
Camsprian—Dr. G. Bornemann has recently described the 
fossils of the Cambrian of Sardinia. Many of the forms are 
closely similar to those recorded by Billings from the calciferous 
rocks of the Mingan Islands and other localities bordering on 
the St. Lawrence. Archgocyathus Bill. is very abundant. This 
fossil has also lately been discovered in the Durness limestones 
_ of Scotland. 
studied was that described by Credner as Branchiosaurus ambly- | 
stomus, and by Gaudry as Protriton petrolet. As no less than 
seventy-six examples were studied, a good idea of the life-course 
of the creature was obtained, and it was found that in its early 
stages it was aquatic, breathing by gills supported by four pairs 
of branchial arches. By the time Protriton reached a length of 
to 70 mm. it cast its branchiz and -became an air-breather, 
its development being somewhat analogous to that of the Sala- 
Professor Fritsch, of Prague, has discovered a species of thero- 
morphous reptile of the genus Naosaurus in the Permian beds 
of Bohemia. This genus has been found hitherto only in Texas, 
and was described in this journal, 1886. í E 
_ Trias.—Professor Cope has presented to the American Philo- — 
- sophical Society a description and figure of the cast of the brain- 
* 
