THE RECENT LUNG-FISHES 



125 



Queensland as a plentiful food-fish, a "salmon" in size and 

 taste, although, curiously enough, it remained undescribed 

 until 1870 (Krefft, and Gunther). After this its develop- 

 mental history was eagerly awaited, in the hope that it 

 would reveal the affinities of the Dipnoans to the sharks, 

 amphibians, and in general to the early chordates. About 

 ten years ago Caldwell was sent to Queensland by the 



Fig. 129. The South American lung-fish, Lepidosiren paradoxa, Natter. X . 

 (From NICHOLSON, after NATTERER.) A front view of the mouth is shown at B. 



Royal Society, and succeeded in securing a set of the 

 embryonic stages, but his results still remain unpublished. 

 A second set of embryos was collected in 1891 by Semon, 

 from whose recent paper a summary is later given (p. 198). 

 The development of Ceratodus, however, as far as it is at 

 present known, has proven in many ways unsatisfactory to 

 the phylogenist ; its abbreviated growth stages cannot be 



