ORNITHOLOGICAL EXPLORATIONS. 41 



when the excrescence tlries up, in the prepared skin forms a furrow. 

 The color is white slightlj^ tinged with flesh color, and in the fresh, 

 bird, therefore, stands out in bold relief against the surrounding parts. 

 On the lower mandible the feathering does not entirely reach the horny 

 part of the beak, and the intervening soft skin is also of a similar white 

 color. 



Thi** tumor was perfectly soft in all specimens whicb I had the oppor- 

 tunity of examining, but as none of these were taken late in the season, 

 and I have never seen a winter specimen, I am unable to say anything 

 about its later development with certainty. In all probability, how- 

 ever, the surface becomes hardened towards the end of the breeding 

 season ; it then will scale off irregularly during the course of the late 

 autumn, leaving only a small and not very prominent soft space, which 

 again will commence to swell late in the winter, towards the approach 

 of the propagation time, but, as remarked, this is a hypothesis only. 



The sheddingof the basal parts of the bill of this species is not so simjde 

 as Mr. L. Bureau has conjectured.* In fact, the basal portion is not 

 formed by a single piece, as supposed by him, but consists of several 

 deciduous parts. In the spring these are rather difficult to distinguish 

 because more concealed by the adjacent feathers and more completely 

 fused together. During the breeding season, however, the dividing 

 furrows become more distinct and deeper, showing the following sep- 

 arate pieces : 



1. The soft white swelling at the base of the maxillary tomia, the 

 tomial tumor. Comp. pi. iv, fig. 6, and pi. v, fig. 1 a.) 



2. The nasal cuirass, an irregular piece above and behind the nostrils, 

 not continuous with the corresponding piece on the opposite side. 

 (Fig. 1&.) ^ 



3. A small unpaired saddle-piece riding at the base of the culmen, 

 rising knob-like above the latter, and with the ends of its legs just 

 touching the upper corner of the nasal cuirasses. This piece seems to 

 correspond to the " orlef'' of the bill of the FratercuUnw. (Fig. 1 c.) 



4. A small depressed and angle-shaped space behind and below the 

 "orlet" and above the cuirass, between these two pieces and the feath- 

 ering. (Fig. 1 (7.) 



The tomial tumor has already been treated of above. It partakes 



* "Les parties susceptibles de se modifier par I'eflet de la miie sout du resto fort 

 Bimples chez le psiitacula : elles se r^duisent k line eenle p^^cc corn^e, ]a cuirasae 

 namie (pi. v, fig. 2) qui ue fait jamais d6faut dans la fauiille des Moriuonid^s." (Bull. 

 Soc. Zool. Fiance, 1879, p. 50.) 



