ALOEDINES 201 



rings forming the box are not so completely fused, and the 

 larger intrinsic muscle arises much lower down — in fact, at 

 the commencement of the box. 



COLII 



Definition. — Aftersiaft present ; oil gland tufted. Muscle formula, 

 AXT; biceps slip present. Caeca absent. Skull dtsmognatlious. 



Of the family Coliidae there is only a single genus, African 

 m range and including something like nine species. 



The toes are remarkable for the fact that the zygodacty- 

 lous condition can be assumed ; the first toe can be directed 

 forwards,' the fourth backwards. There are ten rectrices ; a 

 tufted oil gland and an aftershaft are present. 



The pterylosis described by Nitzsch is remarkable foi: 

 the width of the pterylse. The ventral tract almost com- 

 pletely covers the ventral side of the body; towards the 

 outside the feathers are stronger, but there is no outer branch. 

 The spiijal tract is narrow and strongly feathered upon the 

 neck ; on the occiput is a bare space, reminding one of that 

 in a similar position in the Trochilidse. There is no median 

 spinal apterion. 



In their myology the colies are remarkable for possessing 

 a fleshy biceps slip. The tensor patagii brevis muscle is ve"ry 

 extensive, and reaches nearly as far as the fore arm. Its 

 very short and single tendon sends back a ' passerine ' slip, 

 obHque in direction, and is also continued over the arm. 



The pectoralis slips to both longus and brevis are present. 



The deltoid, as in so many allied birds, is very extensive. 



The leg muscular formula is AXY— . There is only one 

 peroneal. 



The semimembranosus is inserted below and indepen- 

 dently of the semitendinosus. The latter gives off a tendinous 

 . slip to the gastrocnemius. 



The deep flexor tendons blend before giving off branches 

 to the toes. 



' Hence the term ' pamprodaetylous,' sometimes used for this family. 



