REVIEWS 239 
be the central consideration in the revision of the nomenclature of all 
groups of fossils as well as living organisms. That there has long 
existed a burdensome and extensive synonomy among crinoidal as well 
as all other classes of animals no one who has given the subject atten- 
tion will fora moment question. The most casual consideration has 
rendered apparent the urgent necessity of a careful and complete revis- 
ion of nearly allgroups. The wide geographical distribution of many 
species and the concomitant changes of environment may readily be 
referred to as among the chief causes of local variation in species now 
living. Among fossil forms, however, there is in addition a greater 
factor of geological range which must be carefully considered. Not- 
withstanding the careful and conscientious labors of a large number of 
writers, little attention has been given in the description of species to 
these highly important factors which for the most part have been 
entirely overlooked. But the contributions to synonymy have not 
originated wholly in the manner mentioned. A still greater number 
of invalid names have come from a practice which cannot be con- 
demned in terms too severe. It isthe tendency to describe species, and 
genera also, from imperfectly preserved material, often from a single aber- 
rant specimen, without making adequate comparisons with allied forms. 
This deplorable state of things, which in the natural course of events 
should be continually getting better with the advance of knowledge, 
appears of late years to have become so virulent that it is a serious 
question whether such work should not properly be ignored altogether. 
It will ever remain one of the crowning glories of Wachsmuth and 
Springer’s efforts that they have shown no sympathy whatever with 
such work; and that with calm, untrammeled and truly scientific judg- 
ment they have relegated to oblivion such a large number of worse 
than useless specific names which have so long stood as a menace to prog- 
ress in this field of palzontologic research. A full list of synonyms 
so far as they apply to the Camerata is given. 
The preparation of the monograph occupied over seven years of 
continuous work, but this gives but a faint idea of the vast amount of 
labor involved. This work will be indispensable to all future writers 
on crinoids, as well as to the collector in the identification of his mate- 
rial. It embraces the whole literature on the subject and thus dis- 
penses with dozens of papers which are not accessible to the student. 
Besides it has the great advantage that the same terms are used through- 
out the whole work, and that these terms are clearly and accurately 
