246 Evolution and Distribution of Fishes 



included 543 beetles, 20 Orthoptera, 29 Neuroptera, 81 

 Hymenoptera, 3 Lepidoptera, 64 Diptera and 136 Hemip- 

 tera are all recorded. 



At Oenlngen, which is situated on the north or Baden 

 side of a narrow arm of Lake Constance, occur two lime- 

 stone quarries at a height of 550 feet and 700 feet above 

 the level of the lake. Of one Heer says: "In the lower 

 quarry, immediately upon the yellow marl, there is an 

 extremely fine-grained limestone, which Is only one inch 

 In thickness, and splits into yellowish or grey layers as thin 

 as paper. In these layers the plants and insects are em- 

 bedded, and often are so wonderfully well preserved that 

 they look as if they had been painted." 



The fossil fishes "occur both in the upper and the lower 

 quarry, but are restricted to particular beds. Up to the 

 present 32 species have been described, belonging to 15 

 genera. Of these genera only one [Cycliirus) allied to the 

 carps, but distinguished by its rounded caudal fin is extinct; 

 all the others are still met with living In freshwaters." As 

 to their distribution, then and now, he makes the following 

 suggestive observations: of the genera "which Oenlngen 

 has In common with the existing fauna, only one, the Cottus, 

 belongs exclusively to the temperate and cold regions; all 

 the rest occurring also In Mediterranean countries, or even 

 in tropical and sub-tropical zones. The genera Perca, 

 AcanthopsiSy Cobites, Gohio, Leuciscus and Asphis are also 

 represented in Indian rivers, and eels are found in Madeira 

 and Teneriffe. To this must be added that the fish-fauna 

 of Oenlngen contains a number of species usually belonging 

 to genera of warmer lands. The genus Lehias, represented 

 by four small species, now Inhabits Italy, the East, and 

 America. Poecilia occurs only In the swamps of Carolina 

 and South America, and Cychiriis Is extinct. Thus side by 

 side with those genera which still occur In Switzerland, but 

 the greater part of which extend their range Into warm and 

 even torrid zones, other fishes are found which now ex- 

 clusively belong to hot countries." 



Further on he says: "The fishes of Oenlngen belong to 

 six families. The richest in species Is that of the Carps 

 (Cyprinoidei) which Includes 21 species. Five of these 



