Pterylography of the Houtzin. 349 



the cubitus, where they appear as very small discontinuous 

 feathers, with a degenerate hyporhachis. 



T. minores. — On the dorsal surface, commencing in the 

 carpal region with two rows, an additional row is added 

 proximally, owing to the increased space afforded by the 

 mui^cular surface of the forearm and patagium. They may 

 be described as relatively long feathers. Proximally the last 

 row (pre-axial) is continued for a short distance on to the 

 arm. This series is absent on the hand. 



On the ventral surface there are two cubital rows, 

 widely separated ; the second is continued over on to the 

 raanus. A third row is indicated by the presence of some 

 two or three feathers along the pre-axial border of the muscles 

 of the forearm. 



T. marginales. — There are three cubital rows of this series. 

 Examined from the pre-axial margin of the wing backwards, 

 these rows will be found to become somewhat closely ap- 

 proximated in a direction transversely to the main axis of 

 the wing ; thus groups of three are formed ; between each two 

 such groups a considerable diastema intervenes, interrupted 

 only by a feather in the extreme pre-axial margin in the 

 middle of the diastema ; this feather is longer than its fellow 

 on either side. This arrangement is expressed by the ac- 

 companying dots (:';). A similar arrangement obtains in 

 most birds, but the rows (transverse) are much more nu- 

 merous and so closely crowded as to render a correct inter- 

 pretation difficult. This series connects the pt. alaris with 

 the pt. ventralis, and distally clothes the extreme pre-axial 

 border of the manus. 



On the ventral surface there are three rows of these 

 coverts, of which two run along the extreme pre-axial border 

 of the cubitus, whilst the third is placed a little further back ; 

 the first row is longer, and the second shorter, than is 

 normally the case in other forms. 



Ala spuria (woodcut, fig. 1, p. M7,A.sp.). — The ala spuria 

 is composed of four large " remiges,^' almost equalling in 

 length the t. majores of the cubitus. 



Carpal remex (woodcut, fig. 1, p. 347, C.r.). — On the 



