70 U.S. NATIONAL MUSEUM BULLETIN 2 65 



speckled and blotched with pinkish red; in some cases, described by 

 Schonwetter (1964, p. 569), the spots are less pinkish and more olive- 

 brown. The textui'e of the egg is smooth, the pores indistinct. In 

 Schonwetter's table we find the following dimensions (in mm.): 

 length 18.1 (16.9-19.0); mdth 12.7 (11.9-13.3); weight of empty 

 shell 0.09 grams (0.08-0.11); thickness of shell 0.06; weight of fidl 

 egg 1.55 grams; relative weight of shell to that of full egg 5.8 percent. 

 The eggs of this cuckoo show some resemblance to those of some 

 of its hosts, especially of the genera Malurus, Ephthianura, Neositia, 

 Stipiturus, Gerygone, and Petroica, and little or no resemblance to 

 others, such as Rhipidura, Sericornis, Smicrornis, Cisticola, Chthoni- 

 cola, Calamanthus, Meliornis, Zoster ops, Aeginiha, and Taeniopygia. 



4. C. osculans: monomorphic; elliptical or compressed-oval in shape, 

 uniformly dark reddish-brown or chocolate-brown, very similar both 

 in coloration and in size to the eggs of the most favored host, the 

 speckled warbler, Chthonicola sagittata, also agi'eeing fairly closely 

 vnth those of one of its few other fosterers, the red throat, Pyrrholaemus 

 brunneus, but not similar in color to those of other uTegularly used 

 hosts, the yellow-tailed thornbill, Acanthiza chrysorrhoa, and the 

 ]Mallee heath wi'en, Hylacola cauta. That these latter species all make 

 domed or globular nests with dim internal visibility may help to offset 

 the lack of similarity between their eggs and those of the parasite. 

 According to Chisholm (1935, p. 70) the pigment on the shells of 

 osculans eggs is, at least partly, very superficial, as some ot the reddish- 

 brown color rubs off on moist fingers. The eggs of osculans are very 

 different from those of any of the other glossy cuckoos m their rich, 

 dark color. The nearest to them are the eggs of lucidus and malayanus, 

 which are unmarked, bronze or olive; those of the others are very 

 different, light-colored, and show vaiying degrees of freckling and 

 spotting. For its body size, osculans lays a smaller egg than any of its 

 congeners, 19-22 X 14-15 mm. (eajServenty and Whitell, 1962, p. 268), 

 possibly an adaptation to its highly restricted parasitism on a very 

 few host species. Schonwetter (1964, p. 586) gives the follo^ving 

 measurements (in mm.) for osculans eggs: length 21.1; width 15.5; 

 weight of full egg 2.75 grams. 



5. C. maculatus: present data, chiefly ex Baker (1942, p. 80) and 

 Schonwetter (1964, p. 568) hardly more than suggests that the eggs 

 of this cuckoo are polymorphic. It is difficult from the descriptions, 

 which are all I have to rely on, to state whether there are two or more 

 fairly distinct types or one vai-iable, but not readily divisible, one; 

 eggs are whitish, usually Avith a yeUowish tinge and sometimes a slight 

 pinkish one, and with numerous pale brown-red flecks which are most 

 frequent at the obtuse end of the egg, generally similar to the eggs of 

 some of the sunbird hosts, such as Aethopyga siparaja seheriae. Eggs 



