Analytical Synopsis of the Order of Squall. 367* 



XXXII.' — Analytical Synopsis of the Order of Squali; and 

 Revision of the Nomenclature of the Genera, 



By Theodoke Gili.. 

 Ecad 16th December, 1861. 



§ I- 



ON THE HISTORY OF THE ORDER. 



In tliis memoir, the nomenclature and classification of those 

 Vertebrates which constitute the order of Squali, or that group 

 of Elasmobranchiates characterized by lateral branchial aper- 

 tures, and the absence of naso-pectoral cartilages, are discussed. 

 The group so distinguished appears to be marked by features 

 sufficiently important and peculiar to entitle it to the rank of 

 an order distinct from the Rays. Such distinction has already 

 been conferred on it by Prof, Agassiz in his " Essay on Classi- 

 fication." The orders so separated are then really equivalent, 

 according to definition, with the Artedian and Linnasan genera 

 of Squalus and Raia^ although by the reference of the " saw 

 fish" {Pristis) to the former, a true i-epresentative of the Kays 

 is treated as a shark. 



In order to satisfactorily establish the nomenclature of the 

 Elasmobranchiates, it will be necessary to review the principal 

 works in which they have been described, thus ascertaining the 

 forms known to each zoologist, the genera recognised by them, 

 and the limits by definition and inclusion of those genera ; it will 

 be then comparatively easy to discover the name which should 

 be retained for each. 



The systematic arrangement here adopted is a modification 



of that of Miiller and Henle. The principal differences consist 



in the arrangement of the Scyllioids at another point in the 



series, and their distribution among three families, and in the 



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