AVIAN GENUS CHRYSOCOCCYX 15 



thermore, in the females of both species the ventral bars are very 

 similar, bronze-green in color. 



It may be noted that in the majority of adult males many of the 

 bright-green feathers of the upperparts have vague subterminal dark, 

 but glossy, bluish areas which almost foreshadow the dark violet of 

 C. xanthorhynchus. This is also especially the case w^ith the inner and 

 terminal portions of the remiges, which are often dark purple. This 

 all suggests the not very surprising observation that the difference 

 between the violet xanthorhynchus and the dark green maculatus is 

 not as great as it might seem and that, in an evolutionary sense, it 

 is quite possible to accept a "leap" of such dimensions between two 

 related species. It may be mentioned, at this point, that considerable 

 purplish tinge occurs in adult females of lucidus (in the nominate 

 race, plagosus, layardi, and harterti). While these birds have a dull 

 purplish-bronze color, and not deep-violet as in xanthorhynchus, they 

 serve to indicate that the difference between purple and green is 

 less great than the visual appearance of the end result (as developed 

 in maculatus and xanthorhynchus) might suggest. Also, one cannot 

 help but recall somewhat similar suggestive, green-to-purple plum- 

 ages in some of the African starlings of the genera Lamprotornis and 

 Cinnyricinclus. Tvv^o male xanthorhynchus, in the American Museum 

 of Natural History, both marked "adult," show the extremes of 

 coloration, the upperparts, throat, and breast being purplish-coppery 

 in one and deep violet-blue in the other. 



At this point in our reconstruction of the past vicissitudes of 

 Chrysococcyx we come to the largest and most serious gap in the 

 available evidence, a gap that separates all the eight Indo-Malaysian- 

 Australian species from the four African ones (caprius, cupreus, 

 flavigularis, and Haas). So different are the latter group that it is 

 understandable that a superficial glance at them caused Mathews to 

 think they had little in common with their more eastern relatives 

 and to suggest they may have had a quite separate ancestry. How- 

 ever, this in not an acceptable interpretation, and closer study reveals 

 characters common to both groups. As already mentioned, the absence 

 of any glossy cuckoos from Madagascar and the other, smaller islands 

 of the central and western Indian Ocean suggests that the spread of 

 the group from southern Asia to Africa probably took place in Pliocene 

 or post-Pliocene time. It was, however, sufficiently long ago to have 

 permitted not only much differentiation from their eastern ancestral 

 stock but also to have provided the duration and opportunity for the 

 African glossy cuckoos to have formed two subgroups within them- 

 selves, one containing the didric cuckoo, C. caprius, and the other 

 comprising the remaining three. 



