The Soft-finned Teleostei 359 



genus Cromeria, peculiar to the White Nile, and in contrast 

 to the previous genus has "a long slender air-bladder." 



Though very doubtfully represented by fossil remains 

 It may here be added that the Stomlatidae and the Alepoce- 

 plialidae have generally been viewed by ichthyologists 

 (2:569; 2^7:394) as closely related to the Salmonldae. 

 They are all marine fishes, and as with a few marine Sal- 

 monldae the air-bladder has been absorbed. Such strikingly 

 modified deep-sea fishes as Astronesthes with its phosphor- 

 escent organs, Malacosteus with its huge eyes, or Sternoptyx 

 with weird condensed body, are all evidently end-members 

 of a series of Stomlatidae, that in themselves we would 

 regard as evolved salmonid migrants from Inland waters. 



The pelvic fins of the Alepocephalidae have been ab- 

 sorbed in Platytroctes, while In Aleposomus the scales have 

 ceased to develop. All of these morphological details 

 again suggest that marine fishes are evolved descendants of 

 more primitively freshwater ancestry, and that gradual 

 absorption of the air-bladder goes hand-in-hand with gradu- 

 al passage Into a marine habitat. 



In structural, in evolutionary, and largely in geologic 

 relation, the Haplomi or Esoclformes succeed the above. 

 If the morphologic character shown In the above groups 

 — that Ichthyologists regard as most primitive of the tele- 

 osts — be a true Index, namely, separation of the supraoclpi- 

 tal bone from the frontals by the parletals, then two families 

 of the Haplomi deserve first consideration. These are the 

 Galaxidae and the Haplochitonidae that both show a most 

 suggestive freshwater geographic distribution, though un- 

 known in the fossil state. Galaxias and Neochanna make 

 up the former; Haplochiton and Prototroctes the latter. 



"The genus Galaxias has an Interesting distribution, 

 the species of which it is made up occurring In the fresh- 

 waters of the Southern Hemisphere, viz 8 In New Zealand 

 and neighboring Islands, 7 In N. S. Wales, 3 or 4 in S. 

 Australis, i In W. Australia, 2 in Tasmania, 7 in S. America 

 from Chile southwards, and i at the Cape of Good Hope. 

 One species (G. attenuattis) Is even believed to be identical 

 in New Zealand, Tasmania, South Australia, the Falkland 

 Islands, and South America. This conclusion is probably 



