252 Mr. H. J. Elwes on the Genus Henicurus. 



close to the water. Their food consists of insects, larvae, water- 

 beetles, and small shells. 



In describing the plumage of the several species of Henicuri, 

 there are several points characteristic of the whole genus, which 

 it will be unnecessary to repeat. In all the species the tail is com- 

 posed of twelve feathers, of which the four middle pairs are black, 

 with white tips, and graduated in length from the central pair, 

 which are the shortest. The two outer pairs are entirely white, 

 and about equal in length to the next pair, though they vary con- 

 siderably in this respect in different specimens ; the base of the 

 secondaries and tertiaries is also white, and forms a conspicuous 

 bar on the wings (except in H. velatus) of greater or less breadth 

 according to the extent to which it is concealed by the wing- 

 coverts ; the axillary feathers and greater part of the under 

 wing-coverts, with a bar on the base of the primaries beneath, are 

 also white; the white tips of the secondaries disappear with 

 age, and in fully adult birds are almost imperceptible. 



Genus Henicurus, Temm. 



Bill moderately long, straight and stout; the upper mandible 

 sharply keeled at the base ; gonys well marked ; nostrils lateral, 

 set in a deep fossa, closed from above by a membrane ; gape 

 with a few stiff hairs. Wings moderate, rounded ; first primary 

 short ; fourth, fifth and sixth the longest and subequal. Tail 

 long, forked, of twelve feathers, the four inner pairs of which are 

 graduated in length from the centre. Legs and feet moderate ; 

 middle toe the longest and united to the outer one as far as the 

 first joint ; nails strong and curved. 



CI avis specierum. 



A. Pectore albo. 



a. dorso cinereo : 



a', speculo alari tectricibus celato 1. velatus. 



h', speculo alari conspicuo 2. schistaceus. 



b. dorso nigro : 



c'. Cauda longiore quam ala 3. immaculatus. 



d'. Cauda breviore quam ala 4. scouleri. 



c. capite et collo posticis ferrugineis 5. rtificapUhis. 



