Further Light on the Moult of the Bill in certain Mor- 
monid.e.*— When M. Bureau announced his great discovery, that the 
Puffin moults parts of its bill and eyelids, it was expected that he would 
follow up the matter with an investigation of other birds of the same 
family. This he has done in a highly satisfactory manner, with exactly 
the results that were anticipated. His original paper, published in the 
Bull. Soc. Zool. de France, 1877, we translated for the Nuttall Bulletin. 
It is now republished, in connection with the paper below cited, the two 
together forming under one cover a brochure which has just reached us 
through the courtesy of the author. As we are just closing this number 
of our Bulletin, we can only do this valuable paper the scanty justice of 
stating its principal results. 
1 . M. Bureau establishes for Fratercula and its allies a family Mormoni- 
dce, distinct from Alcidce. He finds F. arclica divisible into three forms, 
armoricana, islandica, and glacialis, the geographical distribution of which 
corresponds to certain isothermals. 
2 . F. corniculata moults the bill almost exactly as F. arctica does, the 
only difference being that one pair of small pieces falls in the latter, but 
not in the former. 
3. Lunda cirrhala moults the bill in substantially the same pieces, lacking 
only the horse-shoe shaped piece encircling the base of the upper mandible. 
It has no moult of the eyelids. “ Sagmatorrhina ” is the young of this bird. 
4. Chimerina cornuia (i. e. Ceratorhina monocerata) moults the horn and 
another small piece. C. “ suckleyi ” is the young, and the adult in winter. 
5. Ombria psittacula moults the nasal shield. 
S. Simorhynchus cristalellus is the most like Fratercula arctica, as it 
moults four pairs of pieces (all the red parts of both mandibles). S. “ dubius ” 
is the adult in winter, after the moult. S. “ tetraculus ” is the young before 
the red horny pieces are developed. 
7. Simorhynchus camtschaticus remains undetermined as to the moult. 
(It would appear to be most like that of Ombria psittacula.') S. cassini, 
Coues,is the young of the species. 
8 . Simorhynchus microceros moults the tubercle. S. pusillus (Pall.) is 
the same bird. 
M. Bureau’s determinations are thus without exception the same as 
those made by the writer in the “ Key to North American Birds,” in 1872. 
This highly important paper is illustrated with six colored plates, show¬ 
ing the points very clearly, and a map of the distribution of the races of 
Fratercula arctica. 
M. Bureau may be said to have entirely reformed our ideas of this in¬ 
teresting family. 
A preliminary title-page of his brochure indicates that he may extend 
his fruitful studies to the moult or other changes of the bill of birds in 
general. We take the liberty of suggesting, as an inviting problem, the 
remarkable seasonal changes of size and shape alleged to occur in the 
bills of certain Fringillidce, notably the genus JEgiotlius.- — Elliott 
Coues, Washington, D. C. 
* 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. 8 vo. Pp. 68 , pll. vi, and a map. 
BuaN.O.O. 5,April, 1880, p. /2T- /1$< 
