PEDIGREES. 189 



do not find them until comparatively near the 

 end. 



Similarly, it is not till we get to the closing 

 chapters, so to speak, of the ancient history of 

 the world that we find any record of the pikes 

 and toothed-carps, the flat-fish such as the sole, 

 turbot, and so on and the cod-fish and haddock 

 tribe. Of the ancestral forms of these, as yet we 

 know absolutely nothing. 



The pedigree of the perch tribe, which em- 

 braces the blennies, gobies, millers-thumbs, angler- 

 fishes, mackerels, sea-breams, coral-fishes, and 

 perches, is of more interest. Not so much, how- 

 ever, on account of what it reveals concerning 

 remote ancestors, which show us the lines along 

 which the living forms have gradually developed, 

 as on account of records of troublous times and 

 days of horror, with which the chapters of the 

 past are occasionally punctuated. 



In the collection of fossil fishes in the British 

 Museum of Natural History, there can be seen a 

 slab of rock containing the fossil remains of a 

 shoal of fishes of the genus Bolopteryx, a near 

 ally of the living perches. These remains are in 

 the most extraordinary state of preservation, and 

 seem to show that this shoal w r as suddenly over- 

 whelmed in some great catastrophe. And this 

 because the fishes are lying one upon another in 

 all kinds of contorted positions, with gaping 

 mouths and gills and erected fins, suggesting 

 suffocation by the escape of volcanic gases at the 

 bottom of the sea. And further, they must have 

 been rapidly interred by the settling of vast 

 quantities of suddenly raised sediment before 



