408 HISTOKY OF GEOLOGY AND PALAEONTOLOGY. 



order; Beneden, Dohrn, Haeckel, Walcott, and others gave 

 still mo're weight to the homologies with the Xiphosura, 

 and associated the Trilobites with this order in the classifica- 

 tion. Billings' discovery in 1870 of ambulatory appendages 

 in a specimen of Asaphus from the Trenton limestone was 

 followed by further discoveries of Trilobite walking-appendages 

 by Walcott (1879). Afterwards antennae were found, and 

 well-preserved specimens formed a basis of more detailed 

 descriptions of the jaw and ambulatory appendages by 

 Matthew (1893), Beecher (1894), and Walcott (1894). Thus, 

 within recent years, Burmeister's conception of the classifica- 

 tory position of the Trilobites has been in many respects 

 .verified, although many palaeontologists still regard them as 

 prototypes of the Isopoda. 



Excellent reports and monographs on the genealogico-mor- 

 phological relations of the Trilobites have been contributed 

 from time to time by Dr. Henry Woodward, whose monograph 

 on the British Trilobites, prepared in collaboration with Salter, 

 is a standard work on this group. 



Charles Darwin established the knowledge of fossil Cirri- 

 pedia (1851-54) upon a scientific basis, and subsequent 

 publications by Bosquet, Reuss, Seguenza, and other palaeon- 

 tologists follow the views advanced by Darwin. 



Many memoirs have been devoted to fossil Ostracods, but 

 their interest is almost exclusively stratigraphical. 



Under the name of Merostomata, the Xiphosura and the 

 extinct ancestral order of the Eurypterida are usually com- 

 bined. Dr. Woodward has made signal advances in the 

 knowledge of this group of Crustacea by his admirable 

 monographs which appeared in the volumes of the Palaeon- 

 tographical Society between 1866 and 1878. The first ac- 

 counts of the Palaeozoic Eurypterids were communicated by 

 Dekay, Harlan (1825), and Scouler (1831). The systematic 

 relationship of the fossil Eurypterids with the living Limulus 

 (King-Crab) was recognised by F. Roemer (1848) and 

 MacCoy (1849), an d the memorable anatomical researches 

 of Thomas Huxley afterwards threw new light on the evolu- 

 tion of the Merostomata. Although of less commanding 

 interest, ample justice has been done in palasontological 

 literature to the fossil Phyllocarida, or the ancestral forms of 

 the Branchiopoda, and also to fossil Isopoda, Amphipoda, 

 Stomapoda, and Decapoda. 



