352 STRUCTURE AND CLASSIFICATION OF BIRDS 



those of other Hmicoline bir<5s, but are apt to be a Httle more 

 compUcated. In Larus argentatus, of which the tendons are 

 represented in the annexed cut, the anterior stronger branch 

 of the brevis tendon gives off a forwards and downwards shp 

 to the extensors of the fore arm, from which arises the usual 

 connection with the longus tendon. There is a second con- 

 nection between the two tendons. At the origin of the 



Fig. 171. — Tensoees Patagii ojj' HliyncJiops (afteb Beddakd). 



t.p,lt tensor longus ; t,p.h, tensor brevis ; B, "wristward slip ; F^ pfttagial fan ; 

 A, tendons to ulnar side of arm, 



patagial fan is a bony nodule, as in the petrel. The tensor 

 longus tendon also gives off a slip (A, fig. 172) to the inside 

 of fore arm which is also present in the auks {q.v.) In 

 Bhynchops (fig. 171, A) there are two such tendons. 



Lestris antarotica, Sterna, a,xid Larus marinus (according 

 to Furbeingee's figure, PI. xix.) are much the same, but are 

 without the additional slips A and B. Of these A is present 

 in Bissa tridactijla. 



The expansor sccundariorum is frequently absent, but it 



