214 Shufeldt, Osteology of Ceveopsis novre-hollandicB. \^J'^^yy\\ 



processes never meet each other to thoroughly co-ossify at their 

 point of meeting, as they do in the Ducks of the genus Dendro- 

 cygna, where the sphenotic process and the lacrymal fuse together 

 at their apical union, forming a complete osseous orbital ring, 

 as in Parrots. 



In Chlofpha^a hybrida not only is the stout sphenotic process 

 much lengthened, but the descending process of the lacrymal is 

 considerably more so, and that to an extent to curve round 

 toward the apex of the sphenotic, beneath the eye, and come 

 within 2 or 3 millimetres of meeting with it at its apex. This is 

 not nearly so much the case in Chlocphaga poliocephala, where 

 quite an interval separates them. (Figs. 2 and 4, Plate XXVIII.) 

 The interval between the apices in these processes is still greater in 

 Tachyeres cinereus, in which species the big lacrymal bone has 

 its free descending process ending in a circular expanded tip, 

 which apparently has no incHnation for backward extension. 

 This is equally true for Hymenolcemns malacorhynchus. In the 

 genera Chen and Anser the two processes in question are far 

 separated, and, instead of there being any inclination for them 

 to meet and fuse together, the end of the descending process of 

 the lacrymal is frequenth' directed forwards {Chen hyperboreiis). 



In Branta canadensis the sphenotic process is large and very 

 long ; but it exhibits no inclination to meet the lacrymal bone, 

 the apex of the descending portion of which is expanded and 

 sometimes bifid, or even trifid (No. 17,980, Coll. U.S. Nat. 

 Mus.) 



All anserine birds, in so far as my observations carry me, have 

 the lacrymal bone very large, and to this rule Cereopsis forms no 

 exception. Here it thoroughly co -ossifies with all the surrounding 

 bones with which it comes in contact, as the frontal, the nasal, 

 and, to a slight extent, mesially, with the thin, shell-like pars 

 plana, which is thrown out against it from within. 



In Tachyeres cinereus — one of the Fuligilince in which the pars 

 plana in no way ossifies — the very large lacrymal is much com- 

 pressed in the lateral direction, and its anterior extending process 

 is conspicuously long, as of necessity it must be in order to reach 

 the nasal of the same side, with which bone it usually articulates 

 by an open suture. 



There is likewise a very poorly developed pars plana in Chlo- 

 ephaga hybrida — a species in which the upper portion of a lacrymal 

 is enormous, being much compressed from side to side, and of 

 a triangular outline. Both in Chloephaga hybrida and C. polio- 

 cephala there is a pneumatic foramen present, at the antero- 

 external aspect of the lacrymal at its lower part. It may also 

 occur in other Geese, but is not so evident in them, while in 

 Branta canadensis I do not find it at all. 



HymenolcBmiis malacorhynchus ])ossesses a very considerable 

 pars plana, it being a double, shell-like formation, completely 

 separating the orbital cavity from the rhinal chambers. In 

 Anser a. gambeli it is incomplete below, as it likewise is in Branta 



