General Notes. 
127 
shield, together with the prominent vertical horn, are cast, the bird then 
becoming C. “ suckleyi .” In Ciceronia microceros , a similar but much 
smaller knob is moulted, when the bird becomes C. “ pusilla The 
change is most remarkable in Simorhynchus, in which, apparently, not 
only the conspicuous rictal plate, and greatly enlarged basal portion of the 
mandible, but also, apparently, the entire sheath of the hilly are moulted, 
the species in this stage being S. “ tetraculus ” (Pall.). Unfortunately, I 
have not been able to examine undoubted winter specimens of Phaleris 
psittacula , but as the bill is exceedingly simple (there being no accessory 
pieces) in this species, during the breeding season, it is quite possible, 
though hardly probable, that no change takes place. 
It is a somewhat singular, and perhaps important circumstance, that in 
nearly every species in which this singular transformation of the bill takes 
place there is little if any change in the plumage, the colors and orna- 
mental plumes of the breeding season being worn all the year round. On 
the other hand, in Mergulus alle, and the species of Synthliborhamphus , 
Brachyrhamphus, Uria , and Lomvia , the bill is simple and entirely devoid 
of deciduous elements, while the seasonal change of plumage is very 
marked. This, however, is also the case in Alca impennis and Utamania 
torda, in which there is an apparently deciduous basal maxillary lamina. 
Besides the doubtful case of Phaleris , we are i not sure as to Ptycorham- 
phus aleuticus. This has the bill more or less corrugated at the base, and 
this corrugation is undoubtedly more conspicuous in summer than in 
winter specimens. Both this species and Phaleris psittacula have an 
unvarying plumage, and on this account we are disposed to refer them to 
the group having a greater or less portion of the bill deciduous, without, 
however, having any better reason for doing so. — Robert Ridgway* 
Washington , D. C. 
[Since the above was put in type, I find that in the announcement of 
the discoveries in question I have been anticipated by Dr. Louis Bureau, 
who treats of the subject in detail in. a very important paper, entitled, 
“Recherches sur la Mue du Bee des Oiseaux de la Famille des Mor- 
monides,” published in the “ Bulletin de la Societe Zoologique de France ” 
(December, 1879, pp. 1-68). The species treated by Dr. Bureau are 
Fratercula arctica (including “ des differentes formes que revet le Frater- 
cula arctica suivant les regions qu’il habite ”), F. corniculata , Lunda cir- 
rhata , “ Cliimerina cornuta ” (= Ceratorhina monocerata ), “ Ombria ” psitta- 
cula , Simorhynchus cristatellus , and S. kamtschaticus. In Phaleris psittacula 
it seems that the nasal shield (“ cuirasse nasale ”) alone is deciduous. — 
R. R.] 
Further Light on the Moult of the Bill in certain Mor- 
MONiDiE.^ — When M. Bureau announced his great discovery, that the 
* Recherches sur la Mue du Bee des Oiseaux de la Famille des Mormonides 
par le Docteur Louis Bureau. Extract du Bull, de la Soc. Zool. de France. 
Paris, 1879. 8vo. Pp. 68, pll. vi, and a map. 
