1058 ZYGODACTYLI 
Z. capensis have been succinctly treated by Jerdon (B. Ind. ii. p. 266) 
and Mr. Layard (B. S. Afr. p. 116) respectively.? 
The affinities of the genus Zosterops are by no means clear. 
Placed by some writers, with the Paridx (T1rTMOUSE), by others 
among the Meliphagide (HONEY-EATER), and again by others with 
the Nectariniide (SUNBIRD), the structure of the tongue, as Dr. 
Gadow (Proc. Zool. Soc. 1883, pp. 63, 68, pl. xvi. fig. 2) shews, 
wholly removes it from the first and third, and from most of the 
forms generally included among the second. It seems safest to 
regard the genus, at least provisionally, as the type of a distinct 
Family—Zosteropidx—as Families go among Passerine birds ; but, 
whether the Australian genera Melithreptus and Plectrorhamphus 
(otherwise Plectrorhyncha) should be included under that heading, as 
has been done, remains to be proved, and in the meanwhile may be 
reasonably doubted. 
ZYGODACTYLI, Vieillot’s name in 1816 (Analyse, p. 25) for 
the birds having two toes before and two behind, which he placed 
as the First “¢ribu” of his Second Order, and thus made the group 
practically equal to Illiger’s SCANSORES, being composed of 7 
Families—(1) Psittacini, with the genera Psittacus, Macrocercus and 
Plyctolophus ; (2) Macroglossi, with Picus and Yunz; (3 and 4) 
Aureoli and Pteroglossi, consisting respectively of Galbula and Ram- 
phastos ; (5) Barbati, made up of Trogon, Pogonia, Bucco, Capito, Monasa 
and Phenicophaus; (6) Imberbi, including Saurothera, Scythrops, 
Leptosomus, Coccyzus, Cuculus, Indicator, Corydonyxz and Crotophaga ; 
and (7) Frugivori, formed by Musophaga and Opexthus. 
1 Tt is a remarkable and, if capable of explanation, would doubtless be an 
instructive fact that the largest known species of the genus, Z. albigularis, 
measuring nearly six inches in length, was confined to so small a spot as Norfolk 
Island, where also another, Z. tenwirostris, not much less in size, occurred ; while 
a third, of intermediate stature, 7. strenwa, inhabited the still smaller Lord Howe 
Island. <A fourth, 7. vatensis, but little inferior in bulk, is found on one of the 
New Hebrides ; but, after these giants of their kind, the rest fall off considerably, 
and some of the smaller species hardly exceed 3} inches from end to end. 
