29G Dr. H. Woochoard—Tlie Position of the Merostomata. 



Memiaspis limuloides from the Lower Ludlow, Shropshire (see Quart. 

 Journ. Geol. Soc, vol. xxi, pp. 482-92, pis. xiii, xiv). 



In 1866 I commenced a monograph of the British Fossil Crustacea of 

 the order Merostomata in the annual volumes of the Palseontographical 

 Society, completed in 1878, in which fourteen genera and eighty-three 

 species are recorded and all the then known British species described 

 and figvired. 



From 1878 to 1911 more than a hundred contributions have been 

 added to our knowledge of this truly wonderful group. 



Special reference should be made to the remarkable work of G. Holm^ 

 on Eurypterus Fischeri from the Upper Silurian of Root-si-kul, in the 

 Baltic island of Oesel. Professor J. M. Clarke writes: "Taking 

 for the subject of his investigations the same Eurypterus fischeri 

 from Oesel, that had been already studied by Nieszkowski and Schmidt, 

 he succeeded by most clever manipulation in isolating the chitinous 

 test of the animal, which in this locality is not metamorphosed into 

 a carbonaceous film, as in other deposits, and was able to elaborate 

 its organization in such detail that E. fischeri has really become the 

 most completely known of all extinct animals, and our exact knowledge 

 of it is quite comparable with that of its recent relatives. 



" By comparison with Limulus, the differences in the appendages of 

 the first and second sternites were referred to their proper sexes. 

 Many details of structure were discovered, such as the minute chelicerae, 

 the epicoxite of certain coxal segments, the endostoraa of the posterior 

 margin of the mouth, the connection of the metastoma with the 

 gnathobase, the clasping organ of the second endognathite of the male, 

 the originally composite nature of the metastoma, corresponding 

 to the chilaria of Limulus, and the interior tubular processes of the 

 female opercular appendage. His work has served to bring out 

 with still greater force the numerous homologies and consequent 

 close relationship of the Eurypterids to Limulus.''^ 



Figs. 1 and 2 give actual reproductions of this remarkable specimen, 

 showing the dorsal and ventral aspect (pp. 294-5). 



To those who are interested in the study of these ancient forms, 

 it may be desirable to mention that a model of Eurypterus Fischeri 

 (by Mrs. Blackman) is exhibited in the Zoological Gallery of the 

 Natural Historj- Museum, Cromwell Road, S.W. 



Foremost of the long list of modern investigators, and following, as 

 Director of the New York State Museum, in the position so long and 

 honourably held by Professor James Hall at Albany, N.Y., stands 

 the name of Professor John M. Clarke, Ph.D., D.Sc, LL.D., 

 For. Corr. Geol. Soc. Lond., and one of the most able and energetic 

 geologists and palaeontologists in North America. 



Assisted by Dr. Rudolph Ruedemann, Professor J. M. Clarke issued 

 last year (1912) from the State Museum, Albany, two grand volumes 

 entitled itlemoir 14, The Eurypterida of New York (one volume 

 of text, pp. 440 quarto, with 121 text-figures, and one volume of 

 88 plates, several of which are large folding plates, and pp. 441-628, 



^ " Ueber eine neue Bearbeitung des Eurypterus Fischeri, Eichw." : Acad. 

 Imp. Sci. Bull. St. P^tersbourg, ser. V, iv, 369, 1896 ; Geol. For. i Stockholm 

 For., Bd. xxi, p. 83, 1899. 



