Report of a Mission to Guam. 115 



inal lines. The caudal and pectorals with a more decided wash 

 of yellowish, and with lighter margins. Five specimens, length 

 3-1 1 inches. Agana, Guam, July 14, 1900. Hab. Western Pacific, 

 Marianas. 



Family BAlvISTlD^.— Trigger-fishes. 



Gknus BAI^ISTBS (x\rtedi) Linn^i^s. 



238-229. Balistes undulatus Mungo Park. 



Head 3; depth 2.25; e^'e 5.50; interorbital 4.50; D. iii, 28; 

 A. 24. Scales 31, in series from base of spinous dorsal to vent, 

 about 48 in lateral line. Caudal peduncle with 6 strong spines on 

 each side, arranged in a double row — sometimes with an extra 

 spine on one side. Color in spirits: A lamp-black; head and body 

 with about 15 oblique or undulating lines of 3'ellowish (reddish in 

 life) about as wide as pupil; a broad line comes from each lip and, 

 uniting about on a line with the eye, extends back to a little past 

 and below the pectorals; another ver\' distinct red line, just above 

 this, extends from the upper lip to anus; a yellow line around lower 

 lip; thorax black, without markings; spinous dorsal black; pec- 

 torals, anal and soft dorsal 3'ellowish, the raj'S dvisky at base; rays 

 of caudal dusk}-, the membrane 3'ellow, the fin white at tip. Two 

 specimens. Length 7 inches. Guam, July 13, 1900. The mark- 

 ings of this species are very w^ell shown in Quoy & Gaimard's 

 figure (Voy. Uran. Zool., p. 208, pi. 47, fig. i), but the caudal 

 peduncle is drawn much too thin. In the specimens examined the 

 caudal peduncle is very short and high, its height 2.50 into head. 

 Hab. Western Pacific, Poh^nesia, Marianas. 



Genus BAI^ISTAPUS Tiles. 



230-233. Balistapus aculeatus (Linn.). 



Head 2.75 ; depth 2.50; eye 5.50; D. iii, 25; A. 22. Scales 

 23, in a series from dorsal fin to vent. The caudal peduncle is 

 armed with two and a half rows of sharp, curved spines with black 

 bases. Fins: Caudal fin contained 6.5 times into length of the fish. 

 Ventrals almost obsolete, represented by a single movable spine. 

 Second dorsal and anal of moderate height. Pectorals short, about 

 as broad as long, their bases black, the ra^'S white. Scales rather 

 large, some osseous scutes behind gill openings. Cheeks entirely 

 scaled. Colors: Sides blackish, with two pairs of oblique whitish 

 or 3'ellowdsh bands descending from middle of sides to the anal fin. 

 A broad black cross band between the eyes. Three blue vertical 

 lines from the eye to the base of the pe(5lorals. A yellowish band 

 runs from the bases of the pectorals along the sides of the head to 



