120 Chronicles of Science. [Jan., 



Upper), and Lower Oolite. Coal is found in the west of the 

 department, immediately underlying the Pennian rocks, and the 

 thickness of the deposits makes the supply practically inex- 

 haustible. Dr. Eeynes believes that other localities only want 

 working to yield coal, and that in St. Aff'rique especially the 

 sandstone is so easy to mine that there would be great probability 

 of remunerative success. Under the name of Lias, the author 

 comprises the whole of the series of marls and hmestones which 

 extend from the top of the Trias to the Oolitic hmestone. The 

 Lower Lias (White and Blue Lias) is subdivided into six fossih- 

 ferous zones — (1) Avicula contoria zone (bone bed), (2) Zone of 

 Ammonites 'planorhis, (3) Zone of A. angulatus, (4) Zone of 

 A. BucMandi (Arieten Kalk), (5) Zone of A. obtusus, (6) Zone of 

 A. oxynotus and raricostaius, and A. armatus; the Middle Lias 

 (Marlstone) comprises — (7) Zone of A. jimhriaius, and (8) Zone 

 of A. margaritaim ; and the Upper Lias (Upper Marls, x\lum 

 Shales, Possidonia Schists) consists of (9) Zone of A. Serpentinus 

 (Possidonien Schiefer), (10) Zone of A. h'frons, (11) Zone of 

 A. jurensis, and (12) Zone of A. opalimis. Several new species 

 are described from these zones, princij)ally from the zones of A. 

 margaritatus and A. hifrons. 



The attention of our palaeontological readers is called to the 

 publication of a work by I)r. Gustav L. Mayr, on ' Flies in Baltic 

 Amber.'* We do not give a resume of its contents, as the subject 

 has only recentlyt been treated at some length in this Journal, in 

 Dr. G. Zaddach's paper "On the Origin and History of Amber." 



In the ' Annals and Magazine of Natural History ' for November 

 is a j)aper by Dr. H. A. Nicholson, " On the Distribution in Time 

 of the Graptolitidae." A careful examination shows that this order 

 may still be considered characteristic of and confined to the Silurian 

 period, notwitljstanding the discoveries of the aberrant genus 

 Dictyonema in the Middle Old Red of America, and in the Tremadoc 

 slates of this country. The genera, and often the species of this 

 order, are so constant in range and distribution, that they afibrd 

 reliable data by which to correlate deposits in different parts of the 

 world. 



Another large group — the Brachiopods — has been treated in a 

 similar manner by Mr. J. L, Lobley, in the ' Geological Magazine ' 

 for November. The vast range in time of this class, its persistence 

 through varied conditions, and its apjxarent extinction during whole 

 formations, such as the Trias, only to reappear Avhen more favour- 

 able conditions obtained, would point to its study as being especially 

 valuable in determining the truth and correctness of any develop- 

 ment theory. 



* ' Die Ameisen tics baltisclieu Bcrusttins.' 

 t ' Quart. Joum. Science,' vol, v., p. 167. 



