600 MANUAL OF PHILIPPINE BIRDS. 
obscure drab shaft-lines; sides of fore breast olive-yellow; remainder of 
under parts bright lemon-yellow. Iris brown; bill black; legs and nails 
flesh-color. Length, about 150. @#male from Bataan Province, Luzon, 
measures: Wing, 84; tail, 69; culmen from base, 16; bill from nostril, 
11; tarsus, 19. A female from the same locality, wing, 81; tail, 66; 
culmen from base, 16; bill from nostril, 11; tarsus, 20. 
—— 585. HYLOTERPE APOENSIS Mearns. 
MOUNT APO THICKHEAD, 
Hyloterpe philippinensis GRANT and WHITEHEAD, Ibis (1898), 241, pl. 5, fig.’ 
1 (egg); SHarpr, Hand-List (1903), 4, 313 (part); OATEes and Rem, 
Cat. Birds’ Eggs (1905), 4, 299 pl. 13, fig. 18. 
Hyloterpe apoensis MEARNS, Proc. Biol. Soe. Wash. (1905), 18, 86; Mc- 
GREGOR and WorcrEstTEeR, Hand-List (1906), 93; Grant, Ibis (1906), 
475 (critical) ; McGrecor, Phil. Jour. Sci. (1907), 2, sec. A, 329 
(Bohol). 
Hyloterpe apoensis basilanica MEARNS, Proc. U. 8. Nat. Mus. (1909), 36, 
442.* 
Pbe’a-oi-toi, Bagobo of Mount Apo. 
Basilan (Steere Exp., Bourns & Worcester, McGregor, Mearns); Bohol (Mc- 
Gregor) ; Dinagat (Everett) ; Leyte (Whitehead) ; Mindanao (Bourns & Worcester, 
Mearns, Goodfellow, Celestino) ; Samar (Steere Exp., Bourns & Worcester, White- 
head) ; Siquijor (Steere Exp., Bourns € Worcester, Celestino). 
Adult.—Similar to H. philippinensis, but the bill decidedly smaller 
and the back bright olive-green. A male topotype measures: Wing, 82; 
tail, 68; culmen from base, 14; bill from nostril, 9; tarsus, 18.5. Speci- 
mens from Bohol differ in having larger bills. A male measures: Wing, 
"5; tail, 62; culmen from base, 15; bill from nostril, 10. A male from 
Siquijor measures: Wing, 84; tail, 69; culmen from base, 17; bill from 
nostril, 11. 
Whitehead found a set of two eggs of the Mount Apo thickhead near 
Paranas, Samar, in June, 1896. The eggs are thus described: “Shape 
ovate. Ground-color brownish cream-color, shading into a zone of deeper 
color round the larger end; the zone is ornamented with spots of pale 
*“Adult male.—Similar to typical Hyloterpe apoensis, but paler throughout, 
with crown brownish instead of grayish; under parts canary-yellow instead of 
lemon-yellow; slightly smaller. Wing, 78; tail, 67; culmen, 14; bill from 
nostril, 9.2; tarsus, 17.5. ‘Iris brown. Bill black.’ 
“Adult female * * *WPaler and dingier than the male; under parts pale 
eanary-yellow from throat backward. Wing, 71; tail, 61; tarsus, 17.5. 
“Remarks.—Specimens in the U. S. National Museum, collected on the Island 
of Siquijor, Philippine Islands, by F. S. Bourns and D. C. Worcester, are exactly 
like Basilan specimens taken in February, 1888, and must be included as belonging 
to this species. Lowland birds from Mindanao Island connect the forms apcoensis 
and basilanica.” (Mearns.) * 
Specimens from Siquijor, although larger than true H. apoensis, seem to be 
nearly like this species in color. 
ee 
