136 



VERTEBRATE ZOOLOGY 



for at least three or four millions of years. The teleosts constitute 

 now a climax group, at the height of its adaptive radiation; a group 

 in which speciaUzation for strange and limited environments has gone 



A 



Fig. 74. — Deep-sea fishes. A, Pholostomias guemei, length 1..5 inches taken at 

 3500 feet; B, Idiacanthus ferox, 8 inches, 16,500 feet; C, Gastrostomas bairdii, 

 18 inches, 2300-8800 feet; D, Cryplopsarus couesii, 2.25 inches, 10,000 feet; 

 E, F, Linophryne lucifer, 2 inches. (From Lull, after Goode and Bean.) 



to extremes; in which structures, especially integumentary features 

 such as spines, scales, and skeletal elements, tend to run to excesses; 

 in which pigmentation and general color characters develop into the 



