156 



OJS T LEPTOSOMA DISCOLOR. 



p. 472. 



Leptosoma is therefore clearly not Cuculine. In the Cuctilidae, too, the 

 obturator internus is triangular in shape, as in the Gallinae and their allies ; 

 in Leptosoma, as already stated, as in Coradas, it is oval. 



The anomalous arrangement of the toes in Leptosoma made me very 

 anxious to observe the disposition of its deep plantar tendons, these, in 

 all " zygodactyle " Anomalogonatous birds, being arranged in a manner 

 quite unique amongst birds and entirely different from that which obtains 

 in the even-toed Homalogonatous birds (i. e. the Psittaci, Cuculidae, and 

 Musophagidaa) *. 



But in Leptosoma neither of these conditions occurs ; on the contrary, 

 the disposition of its plantar tendons is exactly that found in many birds 

 P. Z. S. 1880, with feet of the ordinary structure. This condition is diagrammatically 

 represented in fig. 3 ; as will there be seen, the tendon of ihejle&or longus 

 liallucis (f.l.hS) joins the tendon of i\Q fleocor profundus digitorum(f.p.d.) 

 on the outer side, some little way above the phalanges, and completely 

 blends with it. From the single compound tendon so formed the small 

 slip to the hallux is given off, on the inner side, just before the common 

 tendon splits up for distribution to the three other digits. This is exactly 

 the same condition as that found by Prof. Garrod in Coracias garrula, 

 and by myself in Atelornis crossleyi (in a skin). 



It differs completely from that found in the Psittacidae, Cuculidae, and 

 Musophagida} on the one hand, and that of the Galbulidae, Bueconida), 



Fig. ?. 



f.p.d. 



Diagram of the arrangement of the deep plantar tendons in Leptosoma. 

 f. 1. h., the flexor longus hallucis ; f.p. d., the flexor profundus digitorum. 



and Picidaa and their allies on the other. Therefore this fact, when taken 

 in conjunction with the statements already made as to the natural position 



* Vide Garrod, P. Z. S. 1875, p. 345. 



