75 fMEKGAMN.i: 



SUB FAM. VI. MERGING, 



Ext. Char. Rostrum mediocre, ad apicem angustatum acuminatum et dentibus ad latera 

 instructum. Digiti posteriores lobati. 



Anat. Char. Sternum carina parte anteriore valde angustata et non ad marginem 

 continuata, margine posteriore appendice cnsiformi instructo, et duobus foraminibus ad latera. 

 Processus coracoides antice elongatus. Os furcation arcuatum, rami lateraliter compressi. 

 Trachea uno vel duobus bulbis tubula. Larynx inferior in maribus bulbo osseo instructa. 

 (Esophagus dilateri potest. Gigeria interne magna cavitioue. 



Ext. Char. Bill moderate, narrowed to tire point, acuminate, and at the sides armed with 

 teeth. Posterior Toes lobated. 



Anat. Char. Sternum with the keel anteriorly produced, posteriorly narrowed, and not 

 continued to the margin, furnished with an ensiform process and two lateral foramina. Coracoid 

 process elongated anteriorly. Os furcation arched, the branches laterally compressed. Trachea 

 with one or two enlargements on the tube. The inferior Larynx in the males furnished with an 

 osseous bulb. Oesophagus dilatable. The Gizzard internally with a large cavity. 



Type. Mergus. 



Affinities. Having, under the head Lamellirostres, stated some of the affinities which exist 

 between the family generally and others, we. have merely, under the head sub-families, stated those 

 which hold between each contained in the above family. In both external and internal character 

 the strongest relation exists between the above and that of Fuligulince, the genera Clangula and 

 Harelda in particular, both of which possess the ensiform process on the posterior margin of the 

 Bternunij and the latter a bulb on the tube of the trachea, formed by enlarged rings. The genus 

 Callichen posesses two bulbs, but the skeleton does not approach so nearly as that of the two 

 genera before mentioned. To the Erismaturiuce we suspect the affinity is not so great, certainly 

 not so far as relates to external character, although we have placed them contiguous, there being 

 evidently a double point of affinity to the Divers. 



Habit. The habit of this sub-family is truly acpiatic, its length of body, and legs being 

 placed far backwards, give the birds contained in it great power of diving. Its food consists 

 principally of small fish. 



