154 Evolution and Distribution of Fishes 



Extensive lists of the plants have been given in the 

 past half-century by Lesquereux, Dawson, Lester Ward and 

 Fontaine in this country; by Lindley and Hutton, William- 

 son, Kidston, Seward and others in Britain; by Zeiller, 

 Renault and Grand d.Eury in France; and by Weiss, Feist- 

 mantel, Stur, Barrois and others for Germany-Austria. 

 All agree that wide land areas of low flat swampy character; 

 of warm but moist humid atmosphere, during some seasons 

 of the year, alternating with hot, bright — almost xerophy- 

 tic — conditions at other seasons; were typical. The far- 

 reaching but comparatively shallow waters of lakes, slug- 

 gish rivers and lagoons teemed with such phyllopods as 

 Estheria tenella, Leaia leidyi and a variety of freshwater 

 ostracods. These seem to have formed the food for great 

 shoals of freshwater fishes of rather sluggish habit, as did 

 also the gasteropods and the abundant pelecypods like 

 Carbonicola, Anthracomya, and Naiadites {io6), all or 

 most of which hung by byssus threads from the trunks of 

 the swamp-loving trees, as Dawson and Hind have shown. 

 Alongside these were great eurypterids, whose specific de- 

 tails have been elucidated by H. Woodward (loy), Laurie 

 (70<§': 151, 509) and Glarke-Ruedemann {6^). The last 

 however were fast disappearing, compared with their more 

 giant predecessors of the Lower Carboniferous, Old Red, 

 and Silurian ages. Scorpions, spiders, and insects were 

 abundant, while in the swamps, flood-plain pools, rivers 

 and lakes, a new and diversified fish fauna existed. Before 

 dealing with this in some detail, it might be stated that a 

 rich amphibian evolution had resulted in the appearance of 

 types varying from 2 or 3 inches long to others that were 

 6 to 8 feet. Many of the latter, like their coccostean and 

 other piscine predecessors were heavily armored and clumsy 

 animals. So, if the abundant vegetation of the period 

 caused it to be called "the age of plants," equally truly 

 might it be called "the age of amphibians." The older 

 records by Dawson, Huxley, and Miall as well as the recent 

 publications of the Carnegie Institution (lOg) by Case and 

 Moodie fully demonstrate this. 



Viewed as a whole the fish fauna of the period was 

 surprisingly uniform in general types, but differed in the 



