378 Analytical Synoims of the Order of Squali. ' 



Group Avitbont dorsal stings [Scymnus Cuv.). 



1 . Scymnus j\lH. 2. Lcemargus MH. 3. Echinorhhius Blainv. 

 § 5. No anal ; mouth terminal. 

 (Family Squatin.'e) Squatina. 



The principal feature in this classification is the great increase 

 in the number of families. All the sharks had been previously 

 regarded as members of a single family, while here they are 

 divided among nine or ten. The authors have not, in their first 

 memoirs, named many of these families, and have even failed 

 to indicate a couple as such ; the appellations of those added 

 in parentheses are adopted from their great work. 



The classification deserves every praise, and is certainly a 

 great improvement on the previous ones. The genera are more 

 rigidly circumscribed and more naturally approximated than 

 had been before done, and all the families appear to be entitled 

 to such rank. The division of the sharks with nictitating mem- 

 branes into five families, as was afterwards proposed, appears to 

 be unwarranted. Here, too, the Plagiostomes were, for the 

 first time, divided into two sub-orders, and the true characters 

 assigned to them ; but notwithstanding, Pristiophorus, wliich 

 agrees in all its characters with the Squali, was placed among 

 the Rays. 



12. — Shortly after, the same naturalists published their " Sys- 

 tematische Beschreibung der Plagiostomen," in which they mo- 

 dified their previous arrangement. 



I. section. Sharks with two dorsal fins and an anal fin ; the first dorsal 



over or behind the ventrals. 

 One family, Scyllia. 

 I. ScylHum. II. Pristiurus Bonap. III. Hemiscyllium. IV. Chi- 

 loscyllium. V. Crossorhinus. VI. Ginglymostoma. VII. Ste- 

 gostoma. 



II. section. Sharks with two dorsal fins and an anal ; first dorsal between 



the pectorals and ventrals. 

 First sub-section. With a nictitating membrane and without spi- 

 racles. 



