NO. 2 FOSSIL AND SUBFOSSIL BIRDS — WETMORE 3 



The fossil is important because of its indication, slight though that 

 may be, of the occurrence of ibislike birds at this early period, and 

 in its general similarity to species of this group that still exist. It is 

 the first fossil bird recorded from Alabama. 



While it appears allied to species now classified in the suborder 

 Ciconiae, which includes the families of the hammerhead (Scopus), 

 the storks (family Ciconiidae), and the ibises (Threskiornithidae), 

 its differences, as indicated in the diagnosis, are such that it requires 

 a separate family, Pelagodornithidae, to be allocated in a superfamily 

 Pelagodornithoidea, adjacent to the superfamily Threskiornithoidea. 



The generic name for this interesting species is formed from the 

 Greek root for Plegadis, a widely distributed modern genus of ibises, 

 viz, TrXrjyd';, aSos, and opvK, bird. The specific name, the Latin word 

 "antecessor," signifies a forerunner (or ancestor). 



II. A RECORD OF THE COMMON LOON, GAVIA IMMER 

 (BRCNNICH), FROM THE PLEISTOCENE OF MARYLAND 



The cranium of a loon found in December 1959 on the shore be- 

 tween Chesapeake Beach and Plum Point, on Chesapeake Bay, in 

 Calvert County, Md., has been presented to the U.S. National Mu- 

 seum by Miss Alice H. Howe of Arlington, Va. The specimen 

 (U.S.N.M. No. 22552) is stained dark brown in color and still retains 

 a film of fine clay silt in the deeper impressions. Its appearance, both 

 in color and in the clay deposit, is indication of ancient age and is 

 typical of the Pleistocene deposits that lie above the Miocene beds 

 in the earthern cliffs that line this section of Chesapeake Bay. There 

 is no reason therefore against listing the bone as of that age. 



The bone (fig. 2) includes the upper surface of the cranium from 

 the base of the premaxilla to the foramen magnum, except that the 

 ridge immediately above the foramen is missing, and there are minor 

 breaks in the posterior area of the frontal. Below, the basioccipital 

 area has been lost. 



The bone obviously is representative of an adult of a large species 

 of the genus Gavia. On comparison of 10 skulls of Gavia immer with 

 6 oi G. adamsii, all of adult age, I find that the cranial section in the 

 former averages less massive in form. The angle of the anterior end 

 of the frontals, immediately posterior to their junction wath the nasals, 

 in most is less abrupt, and the transverse width through the heavy 

 postorbital processes is less. In G. adamsii the cranium is more 

 massive, the anterior end of the frontals slopes more abruptly, and 



