390 Evolution and Distribution of Fishes 



to the New Hebrides, i extends from Mozambique and 

 Mauritius to Sumatra, i is in the Moluccas, and 2 extend 

 to Australia. 



Labnis and Crenilahrus are together in marked contrast 

 to the above, and indicate a different distributional line 

 of travel. For the 9 species of Labrus, and the 12 species 

 of Crenilabrus occur as follows : 2 extend from the N. W. 

 African coast, on to the Eurotpean coast and into the 

 Mediterranean, 10 are peculiar to the last, i to Madeira 

 and the Mediterranean, 2 are continuous from the Mediter- 

 ranean to the Black Sea, 4 are peculiar to it. Ctenolabnis 

 and Acantholabrus extend from the Atlantic coasts of the 

 U. S. and Canada eastward to Madeira and the N. W. 

 European seas. Centjolabriis extends from the Canary and 

 Madeira Islands on to the European coasts. The single 

 species of Tautoga occurs along the coasts of the N. E. 

 States; the single species of Maloptenirus is peculiar to 

 Juan Fernandez, and that of Trochocopus is peculiar to 

 the Galapagos. 



Such distributional features reveal conditions resembling 

 those of Pomacentridae, as well as others that fundamental- 

 ly differ. Thus in both families extension and new evolu- 

 tion of species was continued southward by the Gulf and 

 Carribean sea on the one hand, as well as across a Panama 

 or nearby strait of sea into Lower California, and thence 

 down the western S. American coast. But another and 

 striking line of distribution, that is scarcely even suggested 

 by the Pomacentridae, was effected along the northern 

 coastal edge of the South Atlantis continent to N. W. Afri- 

 can shores, and thence gradually into the cold waters of 

 the N. W. European coasts. 



The fossilized remains of Labrus, Crenilabrus and 

 Labrodon from W. and S. Europe, that are of Miocene and 

 Pliocene age, indicate that the north-eastward extension had 

 already taken place in the Miocene period. Phyllodus, 

 Egertonia, and Platylaemus represent however a still earlier 

 and primitive Eocene invasion. The eastward extension 

 of the group, along the tropical or subtropical lower edge 

 of the S. Atlantis continent, into the Mozambique and Indo- 

 Mascarene coasts, resembles that for the Pomacentridae, 



