2. MEGANEURON. 59 



separate in the middle. The carpus wide and short. The carpal 

 bones six, nearly in a single row. The fingers five, all well deve- 

 loped, the second, third, and fourth not differing greatly in length, 

 the fourth the shortest ; the first consisting of two, the second and 

 third of six, the fourth of five, and the fifth of four joints; the 

 second finger two-thirds the length of the arm-bones. 



The skull of the j'oung animal is much shorter and broader than 

 in the adult (Flower, Trans. Zool. Soc. vol. vi. tab. 57). 



1. Catodon macrocephalus. B.M. 



Catodon macrocephalus, Gray, I. c. pp. 196 (f. 54), 202, 387; Synops. 



Wludes fy Dolph. p. 4. 

 Physeter macrocephalus, Flower, Trans. Zool. Soc. vol. vi. p. 309, 



tab. 55 to 61, and woodcuts. 



Inhab. Tropical seas, accidentally in the temperate ones. 



Mr. Flower (Trans. Zool. Soc. vol. vi.) considers C. australis, 

 Gray, I.e. p. 206, fig. 55, the same species ; and certainly there does 

 not appear to be any character in the skeleton to divide them. 



Maury remarks : — " The Sperm-Whale, according to the result of 

 this chart, appears never to double the Cape of Good Hope. It 

 doubles Cape Horn. Since this fish delights in warm water, shall 

 we not expect to find off Cape Horn an under-current of warm 

 water heavier with its salt?" — Maury, Whale- Charts, p. 267. 



How far the species indicated range bej'ond the habitats whence 

 they were received is yet to be discovered and recorded. No doubt 

 their range is influenced by many local circumstances (peculiarities 

 in the currents, and disposition of the food) that are not easily ob- 

 served or understood. 



2. MEGANEURON. 



Meganeuron, Gray, I. c. pp. 386, 387 ; Synops. Whales 8,- Dolph. p. 4. 



The atlas vertebra subcircular, rather broader than high. The 

 central canal subcircular, in the middle of the body, widened 

 above. 



The rest of the animal not known ; it is placed in Catodontidos 

 because this family is the only one that has the atlas separate from 

 the cervical vertebrae and of the simple form. 



1. Meganeuron Krefftii. 



Meganeuron Krefl'tii, Gray, P. Z. S. 1865, p. 440; Cat. Seals $ Whales, 

 p. 388, figs. 94-97 ; Synops. Whales fy Dolph. p. 4. 

 Inhab. Australian seas. 

 Atlas 13 inches wide. 



