174 AULACOMNIUM ANDROGYNUM IN UPPER SWALEDALE. 
better acquainted with the main lines of development and lines of 
variation, also the conditions determining these variations, it is 
certain that the main factor in the discrimination of species will not 
a one-twelfth oil-immersion objective’; but, unfortunately, that 
consummation is still among the things e wished for. In 
leaving this part of the volume it may be added that, in all, there are 
descriptions of no less than 41 genera and 412 species, which, we 
believe, is a much larger number than is to be found in any previous 
publication of a similar character ; that the geographical distribution 
has been worked out from actual specimens ; and that, exercising a 
wise discretion, Mr. Massee has not attempted to carry the synonymy 
further back than 1875, the date of Rostafinski’s Monograph, unless 
justified by the existence of type-specimens. 
Coming now to the third and concluding part of the volume, we 
have a splendid series of coloured plates, in which artistic finish and 
scientific accuracy are combined in a way one rarely sees in an English 
publication of this kind. Fortunately, being as gifted with the 
pencil as with the scalpel, Mr. Massee has been able to paint his 
own illustrations, which have been faithfully reproduced by chromo- 
colour, etc., of the whole organism on an enlarged scale. To the 
student who is feeling his way through the maze of specific distinc- 
tions, and endeavouring to get a correct mental picture of the facies 
of the typical genera and species, these figures will be invaluable. 
We conclude then, as we began, by strongly recommending this 
volume to all who are interested in the A/yxogastres as well as to 
biologists generally. It is the only work in our language which 
deals systematically and comprehensively with the group, and for a 
1 
t c 
English students can appeal. That it is worthy of such a position 
we have endeavoured to show, and if we have not dwelt upon the 
few minor blemishes we have met with, it is because they in no way 
detract from the utility of the volume, and in no degree diminish the 
general and special excellences it exhibits.—T. H. 
Ne OTE—M mee 
1 
month’s issue, but was, by an oversight, unfortunately omitted. —RICHARD BARNES 
The Gardens, Saltburn-by-the-Sea, May 23rd, 1855, 
Naturalist, 
