3 so Analytical Synopsis of the Order of Squali. 



proposed by Agassiz is substituted for tlieir subsequent one of 

 Triglochis / Leptocharias is re-united to Triccnodon^ — errone- 

 ously, I believe ; and Caroharias is subdivided into five sub- 

 genera, to which rank Scoliodon is also degraded. The refer- 

 ence of Pristiophorus to the Squali is a most important im- 

 provement. On the other hand, the right of the five families of 

 the sharks with nictitating membranes to such rank is more 

 than doubtful. The work is altogether worthy of the illustrious 

 anatomists by whom it was published, and marks a new era in 

 the history of the class. The characters of the families, genera, 

 and species, were given with a precision and correctness previ- 

 ously unparalleled, numerous additions were made to the 

 known forms, and the synonymy has been much more correctly 

 digested than had been previously done. The serial arrange- 

 ment proposed by them has been adopted by almost all suc- 

 ceeding selachologists, and the chief variations consist in the 

 different relative value assigned to the various groups of Nicti- 

 tantes, as well as to that section as a whole, and the position 

 assigned to the hammer-headed sharks. Those modifications 

 will be exhibited in the succeeding synopsis of the classifications 

 of difi^erent naturalists. 



13. — Mr. Swainson, in "The Natural History of Fishes, An- 

 phibians, and Reptiles or Monocardian Animals"* (1839), pro- 

 posed the following classification. The generic names in italics 

 indicate sub-genera of those genera printed in roman characters 

 which precede them. 



Order III. Cartilagines. Cartilaginous Fishes. 

 Family I. Squalid.*. Sharks, 



1. Sub-fam. Squalin.«. Ti/jncal Sharks. 



Sqiialus Linn., Alopias Raf., Cerictius Raf. — Dalatias Baf. — Sela- 

 chus. Isurus Raf., Selachus Cnv.,Lamna Cuv. — Rhincodon Smith, 



* Part II. The natural arrangement of tlie classes of Fishes, Amphibians, and 

 Reptiles (pp. 312-319): also Vol. I. pp. 12'7-168, and Vol. II. pp. 191, 192, where 

 they are somewhat dififerently arranged I 



