Descriptiones DiagnosticcB. 413 



dorsali prima capite remota, sat pone pinnas vcntrales sita ; 

 dorsali secunda caiidali propiore ; pinna anali plerumque ante 

 dorsalem secundara sita, sat caudali remota. 



Parascyllium variolatum. 



Heniiscyllium variolatum A. Dumeril. 



Sub-familia CHILOSCYLLIIN^ GUI. 

 Genus SvNCHisMus GUI. 

 ChilosGi/lliincG dorso ante pinnam dorsalem anteriorem non 

 carinato. 



Synchismus tuberculatum. 



Chiloscyllium tuberculatum Muller and Henle. 



NOTE. 

 The pi-eceding diagnoses of tlie new genera of Squali, indicated in the systematic 

 article on the order, are as brief as they could possibly be made consistently with 

 clearness and accuracy. The species described by all preceding naturalists had 

 been at first referred to the new genera, but it has been since deemed more proper 

 to await the publication by Dr. Bleeker of the plates illustrative of his species 

 and the renewed examination of others before finally arranging them. A few 

 species cannot well be referred to any of the established genera, but I have not 

 considered it expedient to propose new ones for them at present. In the mono- 

 graphical synopses of the different iimilies which I hope to be able to submit to 

 naturalists on some future occasion, the families, sub-families, and genera will be 

 fully described and compared, and the extinct, as well as the recent forms, noticed. 

 The former need a very careful revision by one having knowledge of the subject, 

 some writers, subsequent to Agassiz, having been little acquainted with recent 

 forms and not knowing the value to be attached to dentition. 



