184 MR. J. G. GOODCHILD ON THE [Apr. 6, 
lat., in the Arctic Ocean to the Canaries in the South Atlantic, and 
as far as lat. 32° south of the Equator in the Southern Pacific 
Ocean. The specimens will eventually be placed in the Davidson 
Collection in the British Museum. 
P.S.—Since my paper on Atretia brazieri was writtten, I have 
submitted with my friend Mr. J. E. Haselwood, F. R. Mier. Soc., 
all the specimens of Afrefia to microscopic examination. Under a 
ten-inch power the beak-area deltidial plates present some imma- 
ture features similar to those figured by Morse in his ‘ Embryology 
of Terebratulina. The scaly structure of the shell is very apparent ; 
there are no perforations. We observed two long slender narrow 
muscular sears, with a diamond-shaped central one in the interior of 
a ventral valve. The marginal borders of the largest specimen seemed 
raised or swollen. The most puzzling appearance occurs on some 
brown patches on the shell, consisting of circular and elongated sac-~ 
like aggregations. If these bodies are a feature of the shell-structure, 
it seems strange they should be visible in portions of the surface 
only’. 1 hope further to investigate the matter. 
3. Observations on the Disposition of the Cubital Coverts in 
Birds. By J. G. Goopncuitp, F.Z.S., F.G.S., H.M. 
Geological Survey. 
[Received March 16, 1886.] 
The prominent position occupied by the cubital coverts in most 
living birds renders their correct delineation a point of so much 
importance in any figure intended for zoological purposes that it is 
perhaps hardly necessary to offer any apology for submitting a few 
observations upon that subject for the consideration of the Fellows 
of this Society. Both ornithologists and zoological artists have, of 
course, long been aware of the existence of considerable diversity both 
in the relative proportions and in the mode of arrangement of these 
feathers in various groups of birds; but it seems never to have 
occurred to any one that these variations are of such a nature as to 
admit of their being reduced to any system of classification. This 
oversight may be due to the fact that the specimens made use of for 
scientific purposes have necessarily been either spirit-specimens or 
else skins flat or mounted. In the case of the skins especially, such 
specimens cannot, as a rule, be at all depended upon as repre- 
senting the natural order of the feathers in a living state; and 
consequently ornithologists have been led to believe that the subject 
under notice was not worth any serious attention. But a careful 
1 Norz.—More prolonged examination by daylight with different powersp 
showed these appearances to result from the partial overlapping of the cycloidal 
scales of the shell-structure. The presence of parallel rows of spicular pro- 
jections was clearly revealed in the interior of the valves; these occur at 
regular distances from each other, running-from the beak towards the margins 
of the valves.—Aeners Crane, April 26th. 
