1694 Bulletin 47, United States National Museiim. 



orange patch, occupying $ of height of last ray; base of last ray dusky; 

 anal marked in the same way as the soft dorsal ; a very narrow pale edge 

 to soft parts of dorsal and anal ; pectoral black ; caudal abruptly pale at 

 end of black caudal peduncle, with a curved dark streak parallel with 

 edge of fin and nearly the diameter of the eye behind it; behind this a 

 diffuse yellow area parallel with the dark streak ; fin behind with a nar- 

 row pale edging; flap of opercle narrowly pale. East Indies to west 

 coast of Mexico ; taken in abundance on Socorro and Clarion islands by 

 Mr. Richard C. McGregor. Our specimens above described seem to agree 

 in all respects with accounts of the East Indian species. (Hcan-ali-ala, 

 its name at the island of Oualan.) 



Acanthurus aliala, LESSON, Voyage Coquille, Zool., n, 150, 1830, Oualan. (Coll. Lesson 



& Garnot.) 

 Acanthurus glaucopareius, CUVIER & VALENCIENNES, Hist. Nat. Poiss., x, 190, 1835, Oualan ; 



Molucca (after Harpurus glaucopareius, FORSTER, unpublished drawing of specimen 



from Otaheite, called Harpurus nigricans by BLOCK & SCHNEIDER) ; GUNTHER, Cat., u, 



339. 



665. XESURUS, Jordan & Evermann. 

 Xesurus, JORDAN & EVERMANN, Check-List Fishes, 421, 1896 (punctatus). 



Teeth in 1 row, each 5-lobed ; caudal peduncle armed with 3 large bony 

 plates, placed in a right line, each one with a bluntish, nonserrated keel. 

 This genus is close to the East Indian genus, Prionurus Lace"p&de, differ- 

 ing chiefly in the character of the caudal armature, the plates in Prionurus 

 being small, sharper, and in greater number. (edi$, scraping ; ovpd, tail. ) 



a. Body very deep, the depth in adult If in length ; body and fins everywhere covered 

 with round blackish spots; caudal plates with elevated keel (in the male), sur- 

 rounded by smaller tubercles. PUNCTATUS, 2110. 



aa. Body not very deep, not covered with blackish spots. 



b. Body ovate, the depth 2 in length ; coloration nearly uniform. 



CLARIONIS, 2111. 



bb. Body oblong, the depth 2 in length ; a broad brown lateral band. 



LATICLAVIUS, 2112. 



2110. XESURUS PUNCTATUS (Gill). 



(COCHINITO.) 



Head 4; depth If. D. VII, 26, or VIII, 26; A. Ill, 23; V. I. 5; snout 1^-in 

 head; eye 5^; pectoral long as head; ventral If in head; caudal 1J; second 

 dorsal spine 2 in head. Adult (of 16| inches) : Body deep, compressed, 

 covered with fine velvet; anterior profile concave before eye, then con- 

 vex, the short conic snout projecting, lower jaw included. Preopercle 

 obliquely placed, its bony edge slightly roughened. Caudal with 3 stout, 

 compressed, blunt spines, with broad bases, the tips turned upward, the 

 spines whitish, with black bases. Some specimens, probably females, with 

 no other spines ; others, probably males, with many spines, similar in form 

 but much smaller, scattered over posterior half of body, most numerous 

 about the other spines, these black in color. Young with 3 small blunt 

 lamina only. Gill rakers extremely small and weak. Caudal evenly 

 lunate; pectoral not falcate. Teeth f on each side, incisor-like, lobate. 



