1888.] PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 233 



yytj» 



The frouto lacrymal region we observe to be unusually elongated, 



and in this form concaved in a longitudinal median direction. This 



latter feature obtains also in the Mallard and the Teals, where it is 



quite as well marked, while, on the other hand, in the Swans, Brant, 



and Geese this fronto-lacrymal region is not so strikingly lengthened, 



being flat in some of the latter and mounded up in some Cygnirwe. 

 The space between the orbital margins on 



this aspect shows considerable width, more 



particularly in such forms as Glautionetta, 



where it is marked by a longitudinal median 



crease. 



The supraorbital glandular depressions for 



the nasal glands, so prominent in many of the 



Auks and other water fowl, are here in the 



Anatidce rarely well marked. 



In Spatula they consist in a very narrow 



trimming off of the edge of the orbital periph- 

 eries, barely perceptible in the Mallard and 



Anas carolinensis. In Glaucionetta they are 



better developed, but in this Duck they are 



really moved down so as to form one of the 



features of the lateral aspect of the skull 



(Fig. C3, «7, Coues's "Key," 2d ed.). They 



are quite well marked in the Hutchiu's Goose. 

 Spatula, Anas boschas, and the Teals have a 



strongly incised notch on either side, at the 



anterior arc of the supraorbital rim, which 



seems to define the posterior ending of the 



lachrymal bone. It is absent in the Garrot, 



but again characteristic in Swans and Geese. 

 The vault of the cranium behiud is, upon 

 this aspect, usually smooth and rounded. A 

 longitudinal crease may pass it in the middle 

 line, and elevations on either side in some 

 forms (Spatula, Olor) faintly indicate the divi- 

 sions of the encephalon within. 



Turning now to the under view of the skull 

 of the Spoon-bill, we are to note the great con- 

 cavity of the prem axillary, with its sharply- 

 defined parial gutters for vessels and nerves ai I their ramifications. 



As is well known, all the Anatidw exhibit tin typical desmognathous 

 arrangement of the palatal bones. The niaxill.) palatines unite in the 

 middle line to form a large bony mass (Mxp), in front of which there 

 occurs in all the CheuomorphaB, that I have been enabled to examine, a 

 more or less cleanly cut elliptical opening, the remnants of a much 

 greater vacuity of other birds. In the Swans these maxillo palatines are 



'Vm. 17. Under side of the skull 



I ,.,■ alula clypeata ; mandible re- 



,, ,.!,!. life size. Same specimen 



with Mxp, maxillo-palatine, and 



the other letters as before. 



