1690 Bulletin 4.7, United States National Museum. 



This genus includes those Teuthididcv which have the tail armed with 

 a sharp, antrorse, lancet-like, movable spine; strong, fixed, incisor teeth; 

 ventral rays, I, 5, and usually 9 spines in the dorsal fin. The numerous 

 species are found in all tropical seas ; herbivorous fishes, living about coral 

 reefs ; the adult protected by the murderous caudal spine, which grows 

 larger with age. (revOtt, the Squid, Loligo; substituted by Linnaeus for 

 Gronow's name, Hepatus, for no evident reason.) 



a. Caudal spine small; species pale, barred with black. TRIOSTEGUS, 2104. 



aa. Caudal spine strong; species not pale, barred with black. 



&. Dorsal and anal without yellow streak, widened behind on dorsal and anal. 

 c. Outline rhomboid, the depth 1^ in length, color brown, washed with deep 

 blue. C.ERULEUS, 2105. 



cc. Outline ovate, the depth about 2 in length; color brown, never blue. 



d. Caudal simply lunate. HEPATUS, 2106. 



dd. Caudal deepty emarginate. 



e. Upper lobe of caudal not filamentous. CRESTONIS, 2107. 



ee. Upper lobe of caudal produced in a filament. BAHIANUS, 2108. 



6Z>. Dorsal and anal with a yellow streak broadened behind ; a flesh-colored crescent 



under eye. ALIALA, 2109. 



2104. TEUTHIS TRIOSTEGUS (Linnjeus). 



Head 3| ; depth If ; eye 2| in snout. D. IX, 23 ; A. Ill, 21. Body ovate, 

 anterior profile gently curved, most convex over eyes; snout somewhat 

 produced, concave above. Dorsal fin moderate, anterior spines more or 

 less concealed in the skin, the longest spines about 1 in snout, the soft 

 rays shorter; first anal spine very short, the third longest, about equal to 

 longest dorsal spines; soft portion of anal about as high as the third anal 

 spine; caudal slightly lunate, the lobes but little produced; pectorals 

 about as ]ong as head; ventrals as long as snout. Color in life, dark 

 greenish or slaty above, with yellowish cloudings; chin, belly, throat, 

 and a narrow strip along base of anal, white ; vertical fins dusky ; anal 

 with a narrow white margin; pectorals plain; ventrals white on under 

 surface ; sides with 5 black bars each about as wide as pupil, the first, 

 beginning just in front of the branchiostegals, extends upward and back- 

 ward across cheek, through eye and to median line of back, where it meets 

 its fellow from the other side ; the second begins at front of dorsal fin and 

 extends downward to base of pectoral from which point it is continued 

 downward in a narrower line beginning on base of pectoral and ending 

 just above base of ventral; the third begins near base of sixth dorsal 

 spine and extends across side to belly at a point midway between anus 

 and beginning of anal fin; the fourth begins on base of first dorsal ray 

 and extends to first anal ray ; the fifth begins at base of seventh dorsal 

 ray and extends across side to base of fifth anal ray ; a black spot on 

 upper side of caudal peduncle." Pacific Ocean; very abundant about 

 rocky islands from New Zealand and Australia to the Hawaiian Islands 

 and the Revillagigedos; not yet found elsewhere in American waters ; our 

 specimens from Clarion and Socorro islands, (triosteyus, rpeit, three; 

 drey GO, to cover.) 



