Brachyramphus marmoratus (Gmelin), Marbled Murrelet. 



brevirostris (Vigors), Kittlitz's Murrelet. 



perdix (Pallas), Partridge Murrelet. 



hypoleucus Xantus, Xantus's Murrelet. 



craverii (Salvadori), Craveri's Murrelet. 

 Comment: The family Synthliboramphidae presents another sharply distinguished 

 and fairly homogeneous type of egg, of which the most characteristic mark is the 

 elliptical ovate shape. The submerged markings indicate a considerable antiquity, but 

 there is no evidence of actual loss of color through troglodytic habit, unless, possibly, 

 in the lighter ground shades of S. antiquus. There is a dull white, unmarked set of 

 this species in the M. C. O. collection. So far as known the eggs of B. hypoleucus 

 and B. craverii exhibit much the liveliest variation; and a marked tendency toward 

 annular coalescence, or cloud capping, in the case of these species alone, would go to 

 support Oberholser's contention of a subgeneric evaluation for Endomychura hypoleu- 

 cus and craverii, or even a generic distinction (Micruria Ogilvie-Grant). 



Of course the assignment of family rank to each of these five groups of Alciformes 

 would be pure assumption, if only the order Alciformes itself were known. There is 

 little corroborative evidence in our structural determination to suggest such phylogene- 

 tic disparity. But we are following authoritative analogies drawn from other groups 

 where known structural differences of familiar, or even subordinal, rank are con- 

 firmed by oological differences much less marked than these which appear among the 

 Alciform groups. Indeed, in all sobriety, there is not another non-Passerine order 

 whose oology is so diverse as that of the Alciformes. The eggs of Cormorants 

 (Steganopodes) and Herons (Herodiones) differ less than do the eggs of the true 

 Auklets (.SSthiidae) and the Auks (Alcidae), and the eggs of the Rails (Rallidae) and 

 Cranes (Gruidae) less than those of Guillemots (Cepphidae) and Murrelets (Synthli- 

 boramphidae). Yet the illustrations offered are by some authorities referred to dis- 

 tinct orders, and by none are afforded less than subordinal rank. The authority of a 

 revision of the Alciformes based upon egg determination is, I believe, beyond question. 



GAPS IN OUR KNOWLEDGE OF EGGS. 

 By A. C. Bent. 



These brief notes are written, at the request of Mr. Dawson, with the intention 

 of calling the attention of oologists to certain species of birds, on the North American 

 list, whose nests and eggs have never been found, or about whose nesting habits so 

 little is known as to make the need of further information especially prominent. The 

 author does not pretend to "know it all" about American birds' eggs, but his extensive 

 investigations, in his efforts to gather information for the Life Histories of North 

 American Birds, have probably brought to light most of our knowledge on the sub- 

 ject. Any further knowledge, hidden in private note books, collections or publications, 

 which are unknown to him, would be gratefully received as a valuable contribution. 

 Also it is hoped that these notes may serve to stimulate explorers and naturalists 

 to be on the watch for and to report any new facts discovered, which may help to 

 fill in the gaps in our knowledge. Unfortunately eggs usually do not identify 

 themselves; in most cases the value of an egg, as a scientific specimen, depends almost 

 wholly on the care exercised by the collector in identifying it with certainty, on his 

 integrity and ability as an ornithologist and on the honesty of those through whose 

 hands it has passed since it was collected. There are many eggs in collections, 

 probably some in every collection, which have been wrongly identified through care- 

 lessness, ignorance or even intentional fraud. In writing his Life Histories and 

 in these notes the author has attempted to ignore all such specimens, but he may 

 have been mistaken himself in some cases. The following list is given as only tenta- 

 tive; it is open to criticism and invites suggestions. Tt will be continued as the 

 author's investigations progress. 



Whiskered Auklet iEthia pygraaea (Gmelin). 



There are two eggs in the collection of Mr. Charles E. Doe, of Providence. R. I., 

 which are supposed to be of this species. One of these appears to be authentic; it 

 came through Ward's Natural Science Establishment and was obtained by Professor 

 Ward on his visit to Japan. It was collected in the Kuril Islands, where this species 

 is known to breed abundantly, but no further data came with it. This is apparently 

 the only egg of this species in this country. This species breeds from the Commander 

 Islands westward and northward to Kamtschatka and southward towards Japan. It 

 is said to breed in the central and western Aleutian Islands, but we failed to find it 

 although we were looking for it especially. 



Marbled Murrelet Brachyramphus marmoratus (Gmelin). 



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