214 Annals of the Carnegie Museum. 



Among the Herons I find skeletons of Ardea ciienilea and A. virescens, 

 and some additional very complete skeletons of Nyclicorax. 



There -is an interesting character to be seen in the skull of the 

 Herons, and that is the condition of the basi -temporal bone. The 

 entire forepart of this element is a free, triangular scale, instead of the 

 usual small antero-median lip of it, underlapping the Eustachian en- 

 trances and arterial foramina. In Botaunis this character is very dis- 

 tinctly marked, so much so that upon a direct lateral view of the skull 

 in that genus, nearly the entire basi -temporal is seen thus to be con- 

 spicuously individualized, and projects directly forwards as a large 

 triangular free osseous plate, having above it a deep transverse groove. 



(3therwise the essential characters of the skull in Botaurus are the 

 same as we find in Ardea, especially in A. virescens. 



Upon comparing the characters of the skeleton of Ardea canilea 

 with those set forth in my synoptical table given above, I find that it 

 answers to them most perfectly, departing from them only in matters 

 of minor detail and of but specific significance. 



Botaurus has all the principal characters of a Heron in its skeleton 

 and comes nearer Nyctiavax than it does to Ardea, and is nearest to 

 Ardea virescens in that genus. For instance, this resemblance is 

 seen in such a character as is exhibited on the part of the os fiirciila. 

 In both Botaurus and A. virescens the symphysial part is transversely 

 broad, and the hypocleidium is absent, its position being occupied by 

 a shallow notch. The supero-median process above it, seen in all true 

 Herons, is also very small. Otherwise the shoulder-girdle and 

 sternum of the Bittern are quite as herodine in character as they 

 are in any other member of the genus Ardea. Botaurus has how- 

 ever, a few distinctive skeletal characters of its own, which, taken in 

 connection with others in its anatomy, plainly point to its being a 

 different genus of birds. For some distance in the pelvis, the inner 

 margins of the ilia run closely parallel to the thin sacral crista, and it 

 is only at one small place, anteriorly, that these bones meet the neural 

 crest of the sacrum. But for the rest, the vertebral chain oi Botaurus 

 is much as it is in Nycticorax. This extends even to its having free ribs 

 on the seventeenth, eighteenth and nineteenth vertebrae (see table 

 above), instead of only at the eighteenth and nineteenth as in Ardea. 



With respect to the long bones of the limbs, they are comparatively 

 shorter and stouter in Botaurus than they are in Ardea, thus again 

 agreeing with Nycticorax ; and in both these genera the hypotarsus of 



