FISHES OF HAWAIIAN ISLANDS. 595 



In somo si)eciinens examined, a row of 5 to 7 Iimjiuou.« spots occupies the median line on tlie lower 

 side of the caudal iieduncle, one inider each scale. Others have a row of similar liut stronger sjiots 

 on the back of tlie caudal peduncle. In either series the spcits vary from ■'> In 7 in number. Similar 

 arrangements are found in lihinoscdpebw roa-ul and iiii({rc:r ( Liitken, Spolia Atlantii'a, Scopelini, p]). 24;! 

 and 246). From the fact that no individual possesses botli the dorsal and the ventral .series, Liitken 

 sugfiests that the position of these spots nuiy he asexual character. Dissection of three s])ecimens of 

 each kind of ( '. i-liirrorephn/iix has shown that such is the ca.se, the males bavin}; the dor.sal series of 

 stronger spots. The smallest specimen showing a trace of these spots is 2.5 nun. long, and the longest 

 specimen in wbicli none are a|iparent is 28 mm. Males are .somewhat more abundant than females. 



General color dark on hack, silvery on lower half of sides, with bluish and red(bsb rellections; 

 dorsal and camlal dusky, lia.se of caudal blackish. 



Specimens were taken at the following stations: No. 8912, .south of Oahu, surface; 392fi, west of 

 Oahu, surface; 3927, west of Niihau, surface; 8929, south of French Frigate Shoals, surface; 3980 near 

 Laysan Island, surface; 3932, near Laysan Island, surface; 3980, south of Oahu, surface; 4009, east of 

 Kauai, surface; 4011, west of Oahu, surface; 414.5, west of Niihau, surface; 418.S, Ijetween Honolulu and 

 San Francisco, lat. N. 28° 13' 42", long. W. 14;')° 44', surface. 



Ccntrobranchus clmmccphalus Fowler, Proc. .\c. Nat. Sci. Phila., 19U3 i.Iaii. I;!. IS)(H), ~TA, near the Saiulwieh [Hawaiian] 

 Islands. (Type. >;o. 7972. .\. N. S. P., Coll. ftr. Win. H. .Tones.) 



Ceutrobranchus gracilicaudus, new species. Plate 69, Fig. 2. 



Type 33 mm. long, from the surface at station 4145, W'est of Niihau Island; type. No. 51518, U. S. 

 Nat. ;\Ius. 



Closely related to ' '. elm roreplialus, \\ith wliich it agrees in all essential features except the following: 

 (1) Supra-anals arranged in an oblique line, the middle spot vertically above the vent, the lowest ver- 

 tically above the fourth of the ventral series. The species differs from ('. cha-rocephfdus, therefore, 

 very much as Rhinoscopchis andrea- (Liitken) differs from lihinosropelus coccol (Cocco). (2) Anals 

 averaging a little more numerous, in the 11 specimens collected, the sum of the two groujis being IG in 

 8 cases, 17 in 12 cases, 18 in 2 cases. The anterior group consists always of 6 or 7 s])ots (6 in 15 cases, 

 7 in 7 cases), while in cliirrorr]>lwbis 5 and 6 are ecjually abundant and 7 is rare. Of postero-anals, 

 there are 9 in 3 cases, 10 in 7 ca.ses, 11 in 12 cases. In rhdroccpliahis 10 is much more abundantly 

 represented than 11. The limited numlier of specimens in the species here described renders the 

 averages not wholly reliable, but they are obviously different from the averages in clin'rimpliiil.iis. 

 (3) Scales of mid-lateral series more persistent, and deeper in proportion to their wiilth. (4) Bodv 

 deeper and snout somewhat less projecting. 



Dorsal 12; anal 19; scales in mid-lateral series 38 or 89. (ireatest depth nf Imdy 2:! hundredths of 

 the total length without caudal; least depth of caudal peduncle 5; length of head 28; diameter of orbit 

 7; interorbital width 7.5; length of snout 7; projection of snout beyond maxillaries 4; length of max- 

 illary 17; distance from tip of snout to front of dorsal 47, from front of dorsal to adipose dorsal 29, from 

 front of adipose dorsal U) rudimentary caudal rays 2(i, from tip of snout to origin of anal 50; length of 

 pectoral 14; length of ventral 10. 



With the exceptions noted, the shape of tlie body, size and relative position of tins, character nf 

 scales, and the number and arrangement of the photophores are as in C. chaToccplmliis. 



Specimens were taken at the following stations: No. 392(), west of Oahu, surface; No. 3927, west 

 of Niihau, surface; No. 3929, southwest of French Frigate Shoals, surface; No. 3930, near Laysan 

 Island, surface; No. 4011, west of Oahu, surface; No. 4145, west of Niihau, surface. 



KKY TO n.VW.\M.\.N Sl'EClES OI' .\1 VCTOPllU.M. 



a. Three pairs of ventral photophores a Ions the inefUan line Jibiilitfuiii. p. .'il'i; 



aa. Four pairs of ventral photophores aloii^ median line. 

 b. Posterolateral single. 



c. Snpra-anals forming a straight line rising obliiinely from near the last ventral iiiarijaritulum, p. .'I'.ltl 



cc. Snpra-anals forming an oblnse-angled triangle, the middle and lower photophores at ahtml Ihe same level. 



the lower much in advance nrftitaimi, p. 597 



bb. Posterolaterals two. 



d. Supra-anals forming an obtuse-angled triangle braucri, p. fi9i 



