THE YEAR'S VERTEBRATE PALAEONTOLOGY 521 



that the articulation can have been of the theriodont type, and 

 we must conclude that Owen's opinion was correct that 

 Tritylodon was a mammal." 



The following interesting case of apparent affinity between 

 anomodonts and mammals given by Dr. Broom in the Zool. 

 Anzeiger (vol. xxviii. p. 106) may likewise be quoted. It has 

 long been known that in the human subject, and apparently 

 in mammals generally, there exists a remarkable peculiarity 

 in the development of the metacarpal bones of the hand and 

 the metatarsals (or corresponding elements) of the foot. In the 

 metacarpal (or first joint) of the thumb and the metatarsal of 

 the great toe the separate cap, or epiphysis, is situated at the 

 basal extremity, whereas in the other metacarpals and meta- 

 tarsals it is developed at the opposite end of the bone. The 

 solution of the puzzle has been found by Dr. Broom, who has 

 discovered that in anomodonts the outermost of the second row 

 of bones in the wrist and the ankle is so elongated as almost 

 to resemble a metacarpal or metatarsal. Owing to this elonga- 

 tion, the main joint of the thumb and great toe appears to have 

 been between the wrist or ankle and the metacarpal or meta- 

 tarsal (as the case may be), while in the other digits this joint 

 was situated between the metacarpal or metatarsal and the first 

 segment of the fingers or toes. Those ends of the bones which 

 took part in the main joint would be the last to ossify, and 

 would determine the points where the caps, or epiphyses, 

 would form. The anomaly in this respect in the human subject 

 seems therefore to be a direct inheritance from reptilian 

 ancestors. 



Work on labyrinthodonts (stegcephalians) appears to have 

 been limited. Prof. H. G. Seeley has, however, described in the 

 October number of The Geological Magazine a new genus and 

 species from the Karoo series of South Africa under the name 

 of Ptychosphenodon browni) and Mr. E. C. Case {Bull. Anier. 

 Mtis. Nat. Hist., vol. xxiii. p. 665) has published notes on remains 

 from the Permian of Texas which throw additional light on the 

 structure of the genus Zatrachys. 



Perhaps the most important contribution to fossil ichthyology 

 is a memoir by Mr. C. R. Eastman on the Devonian fishes of the 

 New York district, published by the New York State Museum. 

 The memoir, in addition to a large mass of descriptive and 

 technical detail, is written from a broad and philosophical 



