Ii6 Direclors Annual Report. 



the snout; a brighter yellow line on premaxillarv. \'ariations: One 

 adult specimen has two extra spines on one side of caudal peduncle; 

 these are just above the normal rows. The young are shorter and 

 deeper, the head being 2.50 into total length, and the depth .2. 

 A good series of specimens were secured, taken for the most part 

 inside the reef, near Agaiia, Guam, June, 1900. Hab. Western 

 Pacific, Marianas. 



234-237. Balistapus rectangulus Bl. 



Head 2.66; depth 2.33; eye 6; interorbital 4; D. iii 23; A. 21. 

 Scales of medium size, entirei}' covering the cheeks; 4-5 osseous 

 plates behind gill openings, three and one-half rows of recurved 

 black spines on sides of the caudal peduncle; no groove in front of 

 eye. Teeth notched and compressed, about 4 on each side of upper 

 jaw. Fins: First dorsal spine ver}' strong, 2.25 into head; caudal 

 square; ventral spine movable. Color in spirits: Olive; belly, tho- 

 rax and chin 3'ellowish; a broad black band with lighter (bluish) 

 edges over top of head through eyes, and widening as it extends 

 obliquely back on sides of body to anas and anterior two-thirds of 

 anal fin. Caudal peduncle encircled with black, which extends 

 horizontally forward on the sides m the shape of an acute angle; 

 this black is edged with lighter colored lines (yellow in life); a 

 light yellow line passes from posterior base of soft dorsal horizon- 

 tally forw^ard to the big black line mentioned first; a narrow line 

 extending down from anterior of orbit to a little in front of pectorals; 

 the interorbital space is cros.sed by three narrow deeper black lines 

 on the black field; webs of spinous dorsal and base of pectorals 

 black; fins yellowish white. Four specimens, 4-6 inches in length. 

 Agaiia, Guam, June 28, 1900. Hab. Polynesia, Western Pacific, 

 Marianas. 



Family MONACANTHID^.— File-fishes. 



Genus AMANS:^S Gkay. 



238-241. Amatises sandwichensis Gray. Paloman. 



Head 3.25; depth 2; eye 5; interorbital 3.50; D. i 36; A. 31. 

 Scales minute, the skin velvety to the touch. Two pair of strong- 

 curved spines on each side the tail. Body elevated and compressed. 

 Profile of snout slightly concave. Dorsal spine without barbs. 

 Caudal fin rounded. Ventral spine not movable. Dorsal spine 

 situated above anterior half of orbit. Color in spirits; A dirty 

 light brown; the soft fins yellowish white; the dorsal spine brown; 

 the caudal dusky with yellowish white on po.sterior part. Four 

 specimens, length 4-12 inches. Guam, Jvily, 1900. The young 



