478 DR. J. MURIE ON THE DERMAL AND VISCERAL STRUCTURES 
narrow, somewhat vertical powder-strip of feathering. Directed both downwards and 
backwards from the axilla to as far as opposite the knee-joint, it is there lost in junc- 
tion with the right and left bands of the lateral sterno-ventral patches of the present 
nomenclature. 
The powder-patch in question I shall call Costo-thoracic (Ct), corresponding as it 
does to the lateral tract (pteryla lateralis), which, according to Nitzsch, is nothing 
more than a branch of the ventral tract. 
I shall consider the distribution of powder-downs upon each fore extremity of 
Rhinochetus as together constituting but a single area, to which collectively the term 
humeral patch (H) is applicable. This, however, is further divisible into four or five 
well-defined segments, viz. brachial, axillary, cubital, and anterior and posterior alar 
subpatches. 
The first of these is that which I have spoken of as springing in part from the 
coracoid patch, of which in a sense it might be reckoned a spur or branch. Whether 
or not, this brachial portion of the humeral patch (/7’) proceeds from over the shoulder 
and clothes the interior proximal end of the humerus like an epaulette. It is nar- 
rowed at its lower extremity, is fully one inch long by three eighths of an inch at 
widest, and is moderately compact in feathering. 
Besides the powder-downs which I have described as occupying the shoulder anterior 
humeral region, there is another less-defined area upon the wing, intermediate between 
the arm and forearm. 
It appears, indeed, as a kind of continuation of the above, but is represented only by 
a series of sparsely scattered short feathers or plumes inserted on both sides of the alar 
membrane. 
These, according to position, if considered distinctly separate, may be regarded as 
alar patches, upper and lower respectively, on each surface of the wing (H“" and H” in 
illustrations, figs. 2 and 3, Pl. LV1.). 
In virtue of their situation, alar patch is a significant term. The wing-tract (pteryla 
alaris) of Nitzsch in some measure includes this patch, while it comprises all the 
feathers inserted upon the wing, with the exception of those which form the humeral 
tract. The upper and lower wing-spaces (apterium ale superius et inferius) also intrude 
upon the sparsely distributed alar powder-patches. 
Another powder-down area, five eighths of an inch long and a quarter of an inch broad, 
is placed on the outer posterior and lower part of each humeral region. This I name, 
for distinction’s sake, the cubital portion of the humeral patch (//° in the left pectoral 
limb of sketch, fig. 2). 
Lastly, near this there is a separate patch an inch and a half by a quarter of an inch 
in its different diameters, situated in the deep posterior aspect of the arm, and stretching 
between the axilla and the elbow in partially divided plumes. 
If these otherwise defined humeral patches be considered but offshoots or isolated 
