899 PALEONTOLOGY OF NEW-YORK. 



AFFINITIES OF THE GENUS EURYPTERUS. 



Dr. Dekay, in his original observations on Eurypterus, referred the fossil 

 to the Branchipodal Crustacea ( Entomostraca), and has indicated the 

 Genera Apus, Binocolus and Lepidurus as the forms to which it seems 

 most nearly allied ; and later writers have expressed similar views of the 

 relations of this fossil*. 



BuRMEiSTER ( op. cit.) has shown the analogies of the Trilobites with 

 the Phyllopoda, in three of the principal genera, Apds, Branchipus and 

 Limnadia; and he suggests that the Eurypterus was a shelless trilobite, 

 as Branchipus is a shelless phyllopod. The EurypterideaB are arranged by 

 him as a fomily with CytherinidesB and Trilobita3, under Pala3adae. 



Dr. F. Il(EMER has suggested the affinity of Eurypterus with Limulus ; 

 indicating, however, the great difference in the feet, etc. Prof. M'CoYf 

 has adopted the same opinion, and has united the Eurypterus and Ptery' 

 gotus in the Family EurypterideaB ( Burmeister). 



Mr. Huxlky|, in his observations on the structure and affinities of Hi- 

 mantopterus ( = Pterygotus), remarks that "Analogies, if not for Himanto- 



* Dr. Hablan has adopted the descriptions and references of Dr. Dbkat without comment, as to 

 the relations of the fossil among the Crustacea; while Dr. IIibbbrt* has cited Dr. Harlan as 

 follows : " The Eurypterus is assigned by Dr. Harlan to the Class Crustacea and to the Order 

 " Bbanchipoda. His description is as follows". Here is given the original description of Dr. Dekat, 

 and then he says : " Dr. Harlan's specimens were obtained from a transition calciferous sandrock 

 " of Westmoreland in the Oneida county of New-York. He has described two fossil species, the 

 " Euryptenu laeugtrit and the E. remipes ( See Plate xii, flgs. 6 & 7)". 



I cite this, to correct both the error in giving Dr. Harlan as the original authority for tliese two 

 species, and also the erroneous reference to localities, as will be seen by consulting the paper of Dr. 

 Harlan. 



Mr. Salter says (Quarterly Journal of the Geological Society, Vol. xv, p. 230) : " Dr. Harlan, 

 " too, in his Medical Researches [Medical and Physical Researches], had given similar but rather 

 " more perfect figures of two species from Williamsvillc, Buffalo, in the State of New-York". The 

 truth is, Dr. Harlan has given a figure of Dr. Dekat's species E. remipa copied from the original 

 figure in the Annals of the New-York Lyceum, as expressly stated by him, for the purpose of com- 

 parison with the proposed species JB. lacuttris, which is less perfect than the figure of E. remipts. 



t BritLih Palicozoic Fossils, page 175. 



X Quarterly Journal of the London Geological Society, Vol. xii, p. 85. 



* Trauaotioiu of the Royal Society of Edlnborgh, Vol. xiii, p. 281. 



