

1871.] 239 [Hyatt. 



modifications departing more and more widely from some central or 

 original type, whether that type be still in existence or not. 



This is undoubtedly the case among the Spheniscidse. Pygoscelis 

 lias a long tail, and step by step the nostrils become feathered; Eu- 

 dyptes begins lower with a short tail, then a long tail is added and the 

 aberrant characteristics of the bill are increased. Throughout these 

 two genera the bill has suffered considerable modification, but only 

 in one species, Pygoscelis adelice, is the mandible sharp at the end, 

 and though every other characteristic of the species may have been 

 changed, the mandible remains straight and truncated. In Apteno- 

 dytes this law of progress is broken through, and we find not only 

 the long tail developed, but a very long and peculiar bill correlated 

 with a system of coloration distinct from that of all the rest of the 

 family, and apparently an exceptional system of nidification. 



According to Jules Verreaux the female of Aptenodytes Pennantii 

 carries one egg between the thighs in a pouch formed by a fold of 

 the skin of the abdomen, this pouch disappearing after incubation; 

 Spheniscus demersus and one species of Eudyptes which were also 

 examined, deposited and hatched their eggs in the regular way. l 



It is hardly necessary to repeat the family characteristics, they are 

 so well known to every one. The wings are mere lateral paddles 

 covered by feather scales on the upper side, but by perfect, though 

 short, feathers on the under side. All the feathers are exceedingly 

 immature, and the tail feathers have unusually large, broad shafts. 



According to Nitzsch there are no apteria. The feathers them- 

 selves are narrow, lanceolate, with a very broad, flat shaft, convex 

 beneath, with the ordinary furrow of the lower surface wanting. 2 

 The terminal barbs are rigid, bristle-like, and flat, at the lower part 

 soft and downy. The aftershaft is recognizable, and similar to the 

 shaft. The tube is short and fusiform, and discriminated from the 

 shaft by a 'deep constriction. No specially formed remiges can be de- 

 tected in the wings, but in the tail stiff rectrices are distinguishable. 

 The feathers of the oil gland circlet have finer but still rigid shafts 

 and much longer, capillary, soft barbs which are downy below. The 

 number of the orifices in the gland was not ascertained. The spe- 

 cies examined by him were Spheniscus demersus and Aptenodytes Pen- 

 nantii. 



So far as my observations have gone there appear to be two forms 



1 Revue Zoologique. 1847. 



2 This is not always the case; often in the younger, and in the wing feathers, 

 and even in some adult feathers, a faint trace of this groove may he observed. 



