NO. 3 BARNARD : THE PHOXOCEPHALIDAE 183 



rostrum. The present research has revealed several species which are 

 intergradations between those with a very narrow rostrum and those 

 with a normally tapering rostrum (Plate 1). However, the use of 

 this criterial pair is a valuable point of dichotomy with which to identify 

 species of the genus and indicates a need to retain an appropriate 

 appellation to denote an artificial subgenus. The writer considers that 

 the narrowing of the rostrum had no single evolutionary beginning 

 and is a polyphyletic mutation (s) occurring repeatedly. The genus 

 Metharpinia is superseded subgenerically by the name Trichophoxus, 

 so that the writer retains the subgenus Trichophoxus ss for species with 

 narrowed or "trichophoxid" rostrums. 



The genus Paraphoxus, as defined by the writer, is a widespread, 

 abundant and variable genus. It offers the zoologist a valuable op- 

 portunity to study distribution, variation, evolution and the cor- 

 respondence of morphology to specific environments. One may ask 

 the questions: Are the same morphological types correlated with the 

 properties of their environment such as temperature and type of sub- 

 stratum? In distantly segregated zoogeographic communities of similar 

 physical properties such as western Australia and southern California, 

 do the same morphological types occur in each community? Are they 

 in the same ratio of abundance? Is their behavior in relation to other 

 community members the same? Is their position in the food chain 

 the same? etc. Finding differences in communities on this zoogeographic 

 basis may well answer a perplexing evolutionary problem as to whether 

 centers of origin occur from which highly successful groups have origin- 

 ated and spread throughout the marine environment. 



Since discriminating systematics is the first step in studying zoo- 

 geography and regional evolution, the following systematic discussion 

 of Paraphoxus may be useful to systematists identifying the many forms 

 of the genus. 



Important Systematic Features in the Genus 



Paraphoxus* 



While the present study was in progress a chart of the species of 

 the genus was compiled and the criteria of each checked 

 off in appropriate squares (Tables 1 & 2). It was seen from the 



*See J. L. Barnard 1958 for condensed version of this section. 



