Scheme of Classification 



CLASS PISCES (FISHES) 



Sub-class I Cyclostomata (Hagfishes and Lampreys). Also known as Cyclostomi, and as 



Marsipobranchii. 

 ORDER I MYXINOIDES (Hagfishes). Also known as Hyperotreti. 

 Family I Myxinidce. 

 Genus 1 Myxine 



limosa 1 (American Hagfish) 

 Family II Eptatretidce 



Genus 2 Polistotrema 



stouti 2 (California Hagfish) 



ORDER II PETROMYZONTES. (Lampreys). Also known as Hyperoartii 

 Family HI Petromyzonidce 

 Genus 3 Petromyzon 



marinus 3 (Great Sea Lamprey) 

 unicolor 4 (Landlocked Lamprey) 

 Genus 4 Ichthyomyzon 



concolor 5 (Silver Lamprey) 

 castaneus 6 (Northern Lamprey) 

 Genus 5 Entosphenus 



tridentatus 7 (Three-toothed Lamprey) 

 Genus 6 Lampetra 



aurea 8 (Brook Lamprey) 



cibaria 9 (Brook Lamprey) 



wilderi 10 (Small Black Lamprey: Brook Lamprey) 



Sub-class II Elasmobranchii (Sharks, Rays, and Chimseras). Also known as Selachii and as 



Chondropterygii. 

 ORDER III PLAGIOSTOMI (Sharks and Rays) 



Sub-order 1 Diplospondyli. (Plagiostomes in which the centra are imperfectly 

 segmented, and joined in pairs, and each pair bearing two neural arches.) 

 Family IV Hexanchidce. 1 Known also as Notidanidae. 

 Genus 7 Notorhynchus 



maculatus 11 (Cow Shark) 

 Genus 8 Hexanchus 



corinus 12 (Shovel-nosed Shark) 



Sub-order 2 Asterospondyli. (Plagiostomes in which the calcification of each 



centrum in cross section radiates star-like from the central axis.) 

 Family V Scylliorhinidce. Scylliidse in part of some. 

 Genus 8a Scylliorhinus 



prof undorum 12a (Roussette). See addenda p. 117 

 Genus 9 Catulus 



brunneus 13 (Cat Shark: Swell Shark) 



'Although this family contains sharks which have 7 gill apertures on either side, Hexanchus has priority over 

 Notidanus, and the name of the family should conform to that of the typical genus. 



