April 25, 1913] 



SCIENCE 



631 



SCIENTIFIC BOOKS 

 The Eurypterida of New York. By Drs. 



John M. Clarke and Rudolf Ruedemann. 



New York State Museum Memoir No. 14. 



Albany. 1912. 2 vols. 



This handsome memoir, illustrated by 121 

 text-figures and accompanied by an atlas of 

 beautifully engraved plates, marks a notable 

 addition to the series of special monographs 

 published by the New York State Educational 

 Department, the importance sf which from a 

 purely scientific standpoint can not be over- 

 estimated. Granted that a knowledge of the 

 wonderful world we live in and of the mani- 

 fold variety of life inhabiting it is of value for 

 its own sake, even though it yields no direct 

 material returns, there can be no question that 

 the publication of this series of memoirs has 

 contributed largely toward the advancement 

 and difl:'usion of knowledge, in which respect 

 the empire state long ago took the lead and 

 has set a worthy example for sister common- 

 wealths to emulate. 



The new monograph before us is of a char- 

 acter such as might be expected of two au- 

 thors who are recognized as holding front 

 rank among invertebrate paleontologists. 

 Net merely is this one of the regular contri- 

 butions of trained specialists, valuable though 

 it is as a great storehouse of facts. It is 

 something more besides. Those familiar with 

 the group of organisms considered must ac- 

 knowledge it to be a philosophic essay which 

 bears the stamp of authority, since every- 

 where one finds that conclusions have been 

 reached only after mature deliberation, upon 

 rigorous analysis of the evidence (often com- 

 plex and confusing), and in the light of all 

 previous researches that have been conducted 

 in this difficult field. 



As is befitting a scholarly production, the 

 memoir is embellished by a graceful literary 

 style, in which lucidity and directness of ex- 

 pression are conspicuous elements. Hugh 

 Miller at his best could not have employed 

 a more appropriate and smoothly flowing 

 phrase, though he may have unwittingly in- 

 spired it, for we find his name bestowed upon 

 one of these peculiar-looking creatures which 



in the parlance of Scotch quarrymen are 

 called " seraphim." 



This volume represents the fruition of long- 

 cherished plans, and more than fifteen years 

 of patient collecting, preparation and study of 

 an immense quantity of material. In locali- 

 ties formerly productive of good specimens 

 but now no longer worked, nothing was 

 thought of tearing down and rebuilding many 

 rods of stone wall and foundations of old 

 barns, on the chance of securing a bit of fresh 

 evidence, or of following up a single new 

 clue. In point of diversity, the thousands of 

 specimens which passed under scrutiny dur- 

 ing the preparation of this memoir exceed all 

 other collections in the world. Little wonder, 

 therefore, that so exhaustive an investigation 

 should have yielded important new results 

 and thrown a flood of light upon the structure 

 and relations of this extinct order of meros- 

 tomes. In fact, the organization of eurypte- 

 rids has probably been studied in greater de- 

 tail than that of any other group of fossil 

 animals, and our precise knowledge of them 

 is comparable with that which we have of re- 

 cent arachnids. The theme is a fascinating 

 one, and touches closely on human interests 

 when we consider the theory, recently revived 

 in some quarters, of the arachnid origin of 

 vertebrates. 



The general thesis of the book is that 

 eurypterids, the king crab and other meros- 

 tomes are arachnids, and share a common ori- 

 gin with the scorpion and its allies. As for 

 the scorpions, to which a special section is de- 

 voted in the appendix, it is worthy of note that 

 they exceed all other animal forms of high 

 elaboration in point of racial longevity, having 

 had a continuous existence from the Silurian 

 onward. 



A very important chapter is that which is 

 devoted to a comparison of the anatomical 

 structure and larval stages of development as 

 observed in eurypterids, Limulus and scor- 

 pions. The conclusions reached from this line 

 of research are: (1) that "the limulids and 

 eurypterids were probably separate in pre- 

 Cambrian time"; (2) that "neither Limulus 

 nor the scorpions are derivable from the 



