THE CUCULIN.E. 91 



A. With ten reclrices : contour-feathers always without an after-shaft. 



a. The pectoral portion of the inferior tract is dilated, uniformly sparsely feathered, 



and extended over the whole breast. 



Ct/cul/ts (Plate IV, figs. 11 and 12). This genus is further distinguished by the circum- 

 stance that the inferior tract is divided from the throat itself; that its ventral part is very broad, 

 and far from reaching the anus ; and that the spinal tract, which encloses a large, lanceolate space, 

 extending from the commencement of the shoulder to the caudal pit, is dilated over the whole 

 hinder part of the back, coalesces with the lumbar tracts, and is very sparsely feathered. The 

 very long caudal process, densely clothed with large feathers, is also one of the generic peculiari- 

 ties, as also the extremely weak plumage of the tibial region. The oil-gland is exceedingly 

 slender in both halves, but is completely immersed up to the tip, and, therefore, appears triradiate ; 

 in front of it there stands on each side a single rigid feather. Rectrices very large, with the cavity 

 of the tube extending for a remarkable distance into the shaft. Nineteen remiges ; the first very 

 short ; the second considerably shorter than the third, which with the fourth and fifth are the 

 longest. The species examined were C. canorus, scrratus, nlandarius, htffiibris, HORSF., and 

 oriental-is ; in the latter the portion of the spinal tract between the shoulders is rather stronger, 

 whilst the portion behind this spot is very weak at its commencement. 



b. The pectoral portion of the inferior tract is not quite so broad, but more densely 



feathered, and encloses posteriorly a narrow insular space. 



The genera Bitbutus, Saurothera, Coccygius, Centropus, Scythrop^, and Crotophaga, which 

 belong to this division, are so similar in their pterylosis, that a merely general description may 

 serve for them. In these (see Plate IV, figs. 13 15) the inferior tract divides rather later, 

 nearly in the middle of the neck, into two limbs, and passes upon the breast with a breadth of 

 four rows of feathers. Here it soon increases to six or seven rows, and then runs with its margins 

 nearly parallel as far as the middle of the breast, where each band divides again into two limbs. 

 The inner limb is continued as the main stem nearly parallel to the crest of the sternum, and passes 

 at the same distance upon the belly, over the lateral surface of which it runs nearly to the anus, 

 before which it terminates. The outer limb departs rather more from the main stem, and turns 

 towards the outer margin of the breast, where it emits a hook, which passes into the hypopterum. 

 Immediately afterwards it again turns inwards, and approaches the main stem, which it rejoins in 

 the form of a small band, usually exactly on the margin of the sternum, thus enclosing an insular 

 space. This course is most distinctly seen in Centropus (philippensis, fig. 13, and rufpcnnis], 

 but nearly as well in Crotophaga ani. Saurothera marginata, KATIP (Cue. viaticus LIGHT.) differs 

 in having both the main stem and the branch narrow, the former biserial, the latter triserial ; and 

 the connecting band consists only of a single row of feathers. In Scythrops novce hollandia 

 (fig. 15), on the contrary, in which both parts are equally distant from each other, they are of equal 

 breadth and triserial, but the connecting band consists of only one row of strong feathers, the 

 greater part of the space being covered with small, sparse contour-feathers. Bubutus isidori, LESS. 

 ('Traite,' p. 145) approaches this form, inasmuch as the space is remarkably small, and enclosed 



