Reviews—Beeby Thompson’s M. Lias, Northampton. 429 
results of his observations on the Middle Lias. The work itself has 
appeared in serial form in the ‘‘ Midland Naturalist,” but the author 
has done well to reprint his papers in a neat and handy volume, and 
so save them from the oblivion which too often befalls many ex- 
cellent articles. 
Two main subjects are treated of and discussed: 1, the Middle 
Lias, stratigraphically and paleontologically ; and 2, the Strata in 
their connection with Water-supply, etc. 
In the first portion we are given detailed notes of many sections, and, 
what is of most importance, records of fossils obtained from each minor 
division of the strata. When we learn that these divisions amount 
to thirteen in all, we may confidently assert that the position of each 
assemblage of fossils in the Middle Lias has been worked out much 
-more minutely than in any other area in this country. In saying so 
much, we do not attach undue importance to these minor or perhaps 
local divisions ; but inasmuch as the author founds his work on the 
stratigraphical sequence of the beds, his facts and conclusions will 
be of great value to other workers, who are endeavouring to trace 
out the biological history of the species. 
Some forms are for the first time recorded from the strata in this 
country ; while others altogether new, obtained by the author, and 
by another zealous worker, Mr. W. D. Crick, have been recently 
described by Mr. EH. Wilson in the pages of this Macazinu. 
The so-called “'Transition-bed” between the Middle and Upper 
Lias, a bed previously discovered and worked out on the borders 
of Oxfordshire and Northamptonshire by Mr. T. Beesley and Mr. E. 
A. Walford, is described as fully as possible. Stratigraphically it is 
a very insignificant bed, but a few inches in thickness, so that 
whether it be regarded as Middle or Upper Lias is a question in no 
ways calculated to disturb the mind of the geological surveyor. It 
has yielded a fauna of upwards of 90 species—about three-fourths 
of which belong to the Middle Lias and one-fourth to the Upper 
Lias. The Ammonites are essentially Upper Lias types, and these 
include the characteristic Ammonites acutus. The Gasteropods are 
of Middle Lias character and suggest that the bed is approximately 
‘on the same horizon as the ‘Pleurotomaria-bed’ (of Mr. E. ©. H. 
Day) on the Dorsetshire coast. 
Mr. Thompson includes in his Middle Lias only the zones of 
Ammonites spinatus and A. margaritatus; thus putting the beds with 
A. capricornus, A. Henleyi, etc., in the Lower Lias—a grouping 
adopted by the Geological Survey. All the evidence, however, goes 
to show that the larger as well as the smaller divisions are 
intimately linked, and the Upper Lias beds in Northamptonshire 
appear in places to be closely connected with the Northampton 
Sands, as pointed out elsewhere by the author. 
Passing on to the second portion of this work, we find a notice 
of the Economic products, and then a general account of the Springs 
in the Gravels and Oolites. The latter portion of this subject is 
but introductory to a special account of the water-bearing beds of 
the Middle Lias. 
