( 509 ) 



XXIV. — The Anatomy and Relations of the Eury-pteridse. By Malcolm Laurie, 

 B.Sc, B.A., F.L.S. Communicated by R. H. Traquair, M.D., F.R.S., F.R.S.E. 

 (With Two Plates.) 



(Read February 20, 1893.) 



Though a great deal has been written on the Eurypteridae, and many points of their 

 anatomy elucidated in the brilliant memoirs of Huxley and Salter, Hall, Woodward, 

 Schmidt,* &c, nevertheless many points of morphological importance remain obscure. 

 This is perhaps to be attributed to the fact that nearly all the writers on this group have 

 treated them rather from the systematic than the morphological standpoint. In dealing 

 with remains so fragmentary and obscure as the majority of these fossils are, the value 

 of some theory as to their relations among recent forms is enormous, both as suggesting 

 points to be looked for and aiding in the interpretation of structures observed. The 

 greater part of the work on this group was done before the arachnid relationship of 

 Limulus was fully appreciated, and it is in the light of a possible relationship to this form, 

 and also to the lower orders of terrestrial Arachnida, that it seemed to me to be worth 

 while to revise the anatomy of the group. It has been necessary to include a certain 

 amount of what is already well known in the description of the different genera, and I 

 have taken special care to confirm, as far as possible, points which seemed to me to rest 

 on insufficient grounds. 



The result of my researches has been to confirm me in the idea that these forms, as 

 well as Limulus, must be included in the Arachnida, and also to suggest a new view of 

 the relation of the different orders of Arachnida to each other. The anatomy and de- 

 velopment of the recent forms has been studied in this connection, but the detailed results 

 of that investigation are not included in this paper, as it seemed more fitting to publish 

 them elsewhere. 



The chief public collections of these fossils which I have examined are those in the 

 British Museum, the Geological Museum Jermyn Street, the Woodwardian Museum in 

 Cambridge, and the Edinburgh Museum, including the recent valuable acquisition of Mr 

 Powrie's collection. I have also had the privilege of examining the large private col- 

 lection of Dr Hunter of Braidwood. I am glad to have this opportunity of expressing 

 my thanks to all those with whom I have come in contact in the course of this work 

 for the invariable courtesy and assistance which I have met with. 



* Huxley and Salter, Mem. Geol. Surv., Mon. i. ; Hall, Nat. Hist, of New York, vol. iii.; Woodward, Monograph 

 of Merostomata. Palseontograph. Soc, 1866-1878 ; Schmidt, Mem. Acad. Imp. St Petersb., vol. xxxi. 



VOL. XXXVII. PART II. (NO. 24). 4 H 



