iean Naturalist 





and the splendid investigations of Thuret and Bornet, has almost 

 wholly altered the classification of the sub-class." Four orders are 

 recognized, based upon the development of the cystocarp; the Mmalio- 

 nacea, Qagartwacpce, Rhodomenamc, < 'njptonnoia^v. The Bxui- 

 (jlureiB, including P, rphyra, are placed at the end of the R ho dophycece 

 as an Anhang. In the last ten pages the Oymophyeect are briefly 

 treated under two orders, the Xosto,;,e,,r ami Ch- ,•<><■<!<■<■„ C eo>. Through- 

 out the work each order and in the larger orders each family is synop- 

 tically treated under four heads ; general character, thallus, reproduc- 

 tion and geographical distribution. In it are embodied the results of 

 the latest investigation on all groups, much having been taken from 

 the able investigations of the author and his associates. Errors are 

 comparatively few, one of the most noticeable being the mentioning of 

 genus Egregia as one of the Fucaceae (P. 55). It is again mentioned 

 in its proper place among the Laminariaceae (P. 85). 



De Alton Saunders. 



Taxonomy of the Crinoids.— The true position of a science in 

 the scale of progress is measured by the degree of perfection exhibited 

 in the systematic arrangement of the phenomena of which it treats. Its 

 chums to philosophic recognition are proportional to the accuracy of 

 the genetic relationships shown in its system of classification. If this be 

 true of a general science, it is no less a reality in its various depart- 

 ments. There is, perhaps, nowhere a better exemplification than the 

 Crinoids ; and no zoological group has made in recent years more rapid 

 progress towards a rational classification. 



The data upon which the systematic arrangement of the stemmed 

 echinoderms rests are elaborately set forth in the lately issued work of 

 Messrs. Charles Wachsmuth and Frank Springer. 2 It is of o-reat inter- 

 est to know that the advancement in an understanding of°the group 

 has been almost wholly from the paleontological side and that the re- 

 sults are accepted practically without change by the most eminent 

 students of the living forms. As is well known, the crinoids are to-day 

 almost extinct; but that in past geological ages they were the most 

 prolific forms of life. On account of the peculiar construction, un- 

 usually great opportunities are afforded for the solution of morphologi- 

 cal problems, and full advantage has been taken. Upon so firm a 

 foundation does the classification of the crinoids, as prepared by Wach- 

 smuth and Springer now rest, that it is hardly probable that it will 

 require radical change for a century to come. 



N..r t l. American i Fossil Crinoidea CameraU : Memoirs Museum Corap. ZooL, 



