1886. | ON A BRACHIOPOD OF THE GENUS ATRETIA. 181 
fact that the modification of the posterior air-sacs in Platalea was 
carried out on doth sides of the body perhaps shows it to be a 
characteristic of the bird. 
Alimentary Canal.—The ceca of Chauna chavaria appear to differ 
slightly from those of Chauna derbiana, the most noticeable difference 
being that they are not symmetrical in the former species ; the right 
cecum is slightly longer than the left, and is of a uniform conical 
shape, tapering slightly to the free extremity ; it measured 33 inches 
from the tip to the junction with the ilium ; the left cecum measured 
as nearly as possible 3 inches. The left czecum also differs in its shape, 
as may be seen by an inspection of the accompanying drawing 
(p. 180); its proximal half is about equal in diameter to that of the 
right caecum, but instead of tapering gradually it narrows abruptly 
into the distal half, which is of about the thickness of the little 
finger. 
In the /iver the right lobe is larger than the left lobe, and, as in 
the other species, there is a large gall-bladder the duct of which 
opens into the duodenum below the hepatic duct ; the pancreatic 
duct is the most anterior of the three. 
Trachea.—The extrinsic muscles of the syrinx are somewhat 
differently disposed from those of Chauna derbiana; as in that 
species, there are two pairs ; the most anterior spreads out in a fau-like 
manner upon a tough membrane which connects the coracoid and 
clavicle; this muscle is therefore attached exactly as is its homologue 
in Ch. derbiana. The posterior pair of muscles are, however, not 
attached to the costal process of the sternum as in Ch. derbiana, but 
terminate upon the aponeurosis of the lung just behind the exit of 
the pulmonary vein. The syrinx itself does not appear to me to be 
worth a special description or figure, as it agrees in every particular 
with that of Ch. derbiana. 
2. On a Brachiopod of the Genus Afretia, named in MS. 
by the late Dr. T. Davidson. By Miss Acnrs Crane. 
(Communicated by Prof. W. H. Flower, LL.D., F.R.S.) 
[Received March 15, 1886. ] 
In July last the late Dr. Thomas Davidson, F.R.S., received from 
Mr. John Brazier, of Sydney, a gift of an interesting series of 
Brachiopoda dredged by him in the waters of Port Stephens and 
Port Jackson, New South Wales. When, in January 1886, it became 
my duty to select the remaining specimens from the Davidson 
collection necessary for the illustration of Parts 2 and 3 of Dr. 
Davidson’s forthcoming Monograph on Recent Brachiopoda, these 
Australian specimens were not found incorporated with his collection 
of living species. Possibly it was Dr. Davidson’s intention to describe 
them in aseparate paper. In February, when the collection of recent 
and fossil Brachiopoda (which, in accordance with Dr. Davidson’s 
