Selachimis Extraordinary 



287 



y 



*9T*r^ 



A Saw shark ( Pristiophorus nudipinnis ) . 



Courtesy, Gilbert P. Whitley 



There are four known species of Saw sharks. Three species belong 

 to the genus Fristiophorus, whose members have five gill openings. Flio- 

 trema has only one known species {zvarreni), and has six gill openings. 

 Pristiophorus species are found in the waters of South Africa, Australia, 

 the Philippines, Japan, and Korea. Fliotrema warreni is found in South 

 African waters. 



Fristiophorus cirratus Latham, 1794, said to grow to more than 4 

 feet, is described as common in Australian waters. Gilbert P. Whitley, 

 the Australian shark authority, reports that this Saw shark's saw-teeth 

 "lie flat against the side of the snout before birth so that the saw shall 

 not injure the mother." 



A rule for the curious: Fristids (Sawfish) and Rhinobatids (Guitar- 

 fish) are "links" in a sense, but they are unquestionably Batoids by 

 definition of the group for the following reasons: 



1. Gill openings confined to ventral surface. 



2. Edges of pectoral fins attached to sides of head anterior to gill open- 

 ings. 



3. Upper margin of orbit not free from eyeball (no free eyelid). 



Likewise, the Squatinids (Angel sharks) and Fristophorids (Saw 

 sharks) are true tiburoids (or Sharks proper) by definition of the group 

 for the following reasons: 



1. Gill openings at least partly lateral. 



2. Edges of pectoral fins not attached to sides of head anterior to gill 

 openings. 



3. Upper margin of orbit free from eyeball (eyelid free). 



These are the links, the curious, difficult-to-classify Selachians which, 

 whatever else their role, serve as the interlocutors between their two 

 branches of kinfolk, the Batoids— and the Sharks. 



