lt>85.] MU. F. E. BKDUARD ON THi; CICKOUS. 181 



row of feathers to the wing; tlie posterior portion of the tract Iroui 

 this point onwards is composed of but a single row of closely-set 

 feathers ; neither here nor in any other of the types examined by 

 me could I see that the two branches of each pectoral tract become 

 reunited, though Nitzsch describes and figures such an arrangement. 



The spinal tract is narrow and very closely and strongly feathered 

 upon the neck ; it is separated by a considerable interval devoid of 

 feathering from the humeral tract ; the latter is of a triangular form, 

 wider anteriorly than posteriorly ; the spinal tract bifurcates between 

 the scapulae, and for the rest of its extent is covered by weak scattered 

 feathering. As in other Cuckoos, the two halves of the spinal tract 

 reunite some way in front of the oil-gland, and form a single tract 

 more densely feathered. 



Crotophagu ani The disposition of the feather-tracts in this 



Cuckoo has been described by Nitzsch. 



Tiie inferior tract commences at the mandibular symphysis and 

 passes back as a single tract to about the middle of the neck, where 

 it bifurcates ; the skin of the throat lying between the rami of the 

 mandibles is bare on either side of the median tract as in Geococcyx. 



The ventral tract is described by Nitzscli (/. c. p. 91) as dividing 

 into two branches, which reunite at a level with the hinder margin 

 of the sternum. Iii an example of C'rotophaga ani examined by 

 myself this was certainly not the case ; the disposition of the two 

 branches of this tract was precisely like what has already been de- 

 scribed in Centropus. 



The head is continuously but sparsely feathered ; between the 

 shoulders the spinal tract bifurcates, each branch being at first but one 

 feather wide ; at the commencement of the double portion of the 

 spinal tract the feathers are very widely separated ; later on they get 

 closer together, and this portion of the tract appears at first sight to 

 be completely separated from the cervical portion. 



The pectoral tract of either side sends off a branch to the 

 humeral tract, to the row of feathers which borders the patagial 

 membrane in front and to the hypopteron ; all these are separated 

 by patches bare of feathers, or with merely one or two feathers scat- 

 tered here and there. 



Eudynamis orien talis. — This bird does not appear to me to agree 

 so closely with Cuculus in its pterylosis as has been stated by 

 Nitzsch ; it differs in that each half of the ventral tract is bifid as 

 in Geococcyx, &c. 



The ventral tract at its commencement entirely occupies the 

 space between the two rami of the mandible ; on the breast the 

 tract is very wide, and is continuous along the tract that se[)arates 

 the wing from the leg with the spinal tract, the axilla itself being 

 alone devoid of feathers ; some way below the axilla the tract 

 divides into two branches, of which the outer one is only a single 

 row of feathers ; these are at first very closely approximated, but 

 gradually become somewhat more widely separated. The outer 

 branch of the ventral tract ceases to be distinguishable some way in 

 front of the pubes. The inner branch is three feathers wide for 



