230 Cincinnati Society of Natural History. 



sisting as the}' did of nierel}' a few fragments of grass or bulrushes so 

 disposed as to prevent the eggs from rolling; in most cases the eggs 

 rested in a slight depression on the bare mud. The sun appears to be 

 their chief incubator, although the decaying vegetation of which the 

 abandoned muskrat houses consist, doubtless play some part in the 

 process. In no instance did we succeed in flushing a bird fiom the 

 eggs^ although they would appear in pairs to the number of twent}' or 

 thirt}^ and hover about within a few feet of our heads making a great 

 outcrj^ when we approached their i))i'opert3% which was soon to be ours 

 by right of discovery. At other times the birds were not at all gregari- 

 ous, being usually observed foraging singl}' or in pairs. Several young 

 of the 3'ear were taken, thus confirming the statement of the resident 

 who informed us that he had taken numbers of the eggs of the first 

 brood in ]^ia3^ Of the dozen or more sets of eggs taken b}^ us early 

 in July, more than half were fresh or nearly' so. 



Order Pygopodes: Divers, Grebes and Auks. 

 Family Colymbid^: Loons. 



93. CoLYMBUS TORQUATus, Brunuich. — Great Northern Diver or 

 Loon. — Three or four specimens observed in summer. [Porter.) 



Famil}' PoDiciPiD^: Grebes. 



94. Podiceps cornutus, Latham. — Horned Grebe C^) — Two sets 

 of eggs taken Jul}' 2d. I refer, with a querj-, to this species as the 

 birds were not seen in either instance. They present such differences 

 however, in shape, coloration and complementary number, that the}' can 

 hardly be credited to P. podiceps^ and I therefore prefer to consider 

 them under the head of P. cornutus, for the present at least. 



These eggs are chalky-white, with a faint, though definite, tinge of 

 pale bluish-green, much like the tint of the Least Bittern's eg^, and 

 very unlike the pale whitey-brown of the eggs of P. podiceps ob- 

 served by us; they are also more elongated in shape than the ordinary 

 egg of P. podiceps^ and taper nearly equally toward both ends, 

 which are decidedly pointed, rather more so than the eggs of P.podi- 

 ceps; another important point of distinction is the number in a full 

 set, which is apparently but two, the complement of P. podiceps being 

 from four to eight. That our sets were probably full is indicated by 

 the fact that one of them contained fully developed young, which 

 swam, and even attempted to dive, on being placed in the water after 

 removal from the Qgg. The nests were similar to those of P. podiceps 

 described below, and the eggs were covered in like manner with decay- 

 ing vegetation during the day and left for the sun to incubate. 



