14 University of Michigan 



15. Dolichorhamphus indicus Willey 



Dolichorhamphus indicus Willey (1901). 



Branchiostovia indicunir TatttrsnW (1903); Herdman (1904); Lonn- 

 berg (1905). 



Family Epigonichthyidae, new family name 



The writer is of the opinion that the extreme asymmetry of 

 Epigonichthys and Asymmetron demands the erection for these 

 two genera of a family distinct from the Branchiostomatidae. 



Genus 4. Epigonichthys Peters 



Epigonichthys Peters (1876); Gill (1905). 



Genotype. — Epigonichthys cidtelhis Peters. 



Paramphioxus Heckel (1893). 



Genotype. — Branchiostoma bassanum Giinther. 



Heteropleuron Kirkaldy (1895). 



GenotA'pe (by present designation). — Heteropleuron cinga- 

 Icnse Kirkaldy. 



Asymmetron Tattersall (1.903); Herdman (1903), etc. (in 

 part). 



The frequent use of the name Heteropleuron for this genus 

 is a wholly unwarranted violation of nomenclatural rules. 



Differences described as distinguishing the species of thi? 

 genus apparently should, in whole or in part, serve as generic 

 or subgeneric criteria, when fully confirmed and better under- 

 stood. The diflferences referred to are : the single or paired 

 postatrioporal caecum ; the single or paired preanal fin-rays ; 

 the presence or absence of preanal rays or chambers; the cla- 

 vate or non-clavate anterior end of the notochord ; the degree 

 of posterior projection of the notochord ; the expanded or 

 normal form of the dorsal fin anteriorly; the separation or 

 continuity of the dorsal and rostral fins ; the presence or 

 absence of the olfactory pit. 



