3. PEIONURUS. 347 



3. PRIONURUS. 



Prionurus, Lac6p. Ann, Mus. iv. p. 205 



A single series of compressed denticulated incisors in each jaw. 

 Tail with a series of several keeled, bony lamina;. Ventral fins com- 

 posed of one spine and five rays. One dorsal fin, the spinous por- 

 tion of wJiich is less developed than the soft and composed of eight 

 or nine spines ; anal spines three. Scales minute. Branchiostegals 

 five ; air-bladder large, forked posteriorly. Intestinal tract with 

 several circumvolutions ; pyloric appendages five. 



Herbivorous fishes from the coast of Japan and the Galapagos 

 Islands. 



1. Prionurus microlepidotus. 



Lacep. Ann. Mas. iv. p. 205 ; Cm: i^- Vul. x. p. 295. pi. 292. 

 D. |. A. If. V. 1/5. C«c. pylor. 5. 



Snout moderately produced, with the upper profile straight. A 

 series of six lamina) on each side of the tail ; a pair of small ones 

 above, and another below that series. Uniform brownish. 



Hab. ? 



2. Prionurus scalprum. 



Acanthurus scalprum, Langsd. 



Prionurus scalprum, Cuv. ^- Val. x. p. 298; Scldog. Faun. Japan. Poiss. 



p. 129. pi. 70. 

 Naseus scalprum, Blcek. Act. Soc. Sc. Indo-Nederl. vi., Japan, vi. p. 79. 



Snout produced, with the upper profile very slightly concave. A 

 series of four or five laminae on each side of the tail. Nine incisors 

 on each side of the upper jaw. Uniform blackish. 



Sea of Japan. 



a,h. Adult: stuff'ed. Japan. Purchased of Mr. Frank. 



3. Prionurus laticlavius. 

 Valenc. in Voi/. Venus, Poiss. p. 335. pi. 7. fig. 2. 

 B.^. A.l. 



2« 25 



Snout produced, with the upper profile very concave. A series of 

 three lamina? on each side of the tail. Eight incisors on each side 

 of the upper jaw. Yellowish : brown along the sides. ( Val.) 



Galapagos Islands. 



4. NASEUS*. 

 I^aaeus, Commerson. 

 Monoceros, JSl. Schn. p. 180. 



* 1. Naseus punctulatus, Cuv.^ Val. x. p. 289. — Hab. ? 



2. unicolor. Lienard {Dix. Bnpp. Soc. Hisf. Nat. Maur. p. ;>8) gives 



the following insufRcicnt dcseriptiou : " Deux lances a la queue. Bleu 



