PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 145 



Vol. VII, No. 10. Wnf^liiiigton, II. C. JsiBy 8, 18 84. 



with clear sky-blue spots separated by olive- green reticulations, the 

 spots arranged in rows; base of pectoral blnish, with olive spots; anal 

 colored like soft dorsal; pectoral greenish. 



164. Monacanthus ciliatus(Mitcliill). Leather-Jish. 



Balistes ciliattis Mitchill, Amer. Mouthly Mag. and Grit. Rev., March, 1818, 



326. ( Straits of Bahama. ) 

 Monacanthus occidentalis Giinther. 

 Monacanthus davidsoni Cope). 



Extremely common about Key West, swarming in the eel-grass every- 

 where. Ko large ones were taken, the longest obtained being about 

 4 inches in length. 



The color varies very much with the surroundings of the fish, from 

 dull olive-gray to the most vivid grass-green. The markings are not 

 well defined and not very constant. 



Green, with white cirri on sides ; a whitish longitudinal cloud behind 

 pectorals ; a i^ale band downward and forward from eye ; lower side of 

 head with darker cross-bands ; dorsal and anal pinkish, with (usually 

 three) darker spots at base ; ventral flap edged with scarlet ; caudal 

 greenish, mottled with darker, and pale. 



Some specimens show neither red nor green shades, and have vague 

 dusky longitudinal stripes. 



This species is more elongate than M. Mspidus. Its ventral flap is 

 much larger, although variable in size, and the caudal in the larger spe- 

 cimens is armed with recurved hooks. Small wbitish dermal flaps are 

 scattered about on the sides. It is most probable that Monacantlius da- 

 vidsoni Cope is this species, although the coloration is usually less defi- 

 nite than Professor Cope's description would indicate. 



165. Monacanthus hispidus (L.). Leather-fish. 



(Monacanthus selifer Auct. ) 



Young specimens abundant in the eel-grass. A single large one (8 

 inches long) taken with a spear in deeper water. 



It is rather less common than the i^receding and passes through very 

 nearly the same series of colors. 



Grass-green or olive ; back and sides with faint, irregular whitish 

 spots ; head plain ; spinous dorsal and caudal green ; second dorsal 

 and anal translucent : adult less variegated ; dull olivaceous, mottled 

 with dusky. 



In the adult the first two soft rays of the dorsal are filamentous, their 

 length being a little less than that of the snout. None of the young 

 show these prolongations. 



Head, 3f in length; depth. If. D. I, 32; A. 33. The young are 

 slightly deeper (1.J) proportionally than the adult. 

 Proc. Nat. Mus. 81 10 



