286 DISCOVERY REPORTS 



Neostoma gracile, Collett, 1896, Bull. Soc. zool. France, xxi, p. 96; Jordan, Tanaka and Snyder, 

 1913, J. Coll. Set. Tokyo, XXXIII (i), p. 50. 



Depth of body 8 to 9 in the length, length of head about 5. Snout about as long as 

 eye, diameter of which is 6 to 6h in length of head and about equal to interorbital width. 

 Suborbital moderately enlarged, not covering entire cheek. A pair of conical teeth on 

 the vomer. Scales apparently absent. About 13 gill-rakers on lower part of anterior 

 arch. Dorsal 11; origin about equidistant from gill-opening and base of caudal. No 

 adipose fin. Anal 26-27; origin well in advance of that of dorsal. Pectoral with 11 rays. 

 Pelvic 7; origin much nearer to tip of lower jaw than base of caudal. Photophores 

 rather small and indistinct ; a series between the branchiostegal rays ; a luminous patch 

 below the eye, in front of which is a small photophore; another, but smaller patch on 

 the praeoperculum ; one supracaudal (?) and two infracaudal luminous patches; some 

 scattered photophores on sides of body in addition to the two rows on the abdomen ; 

 lower series of photophores consisting of 10 from pectoral to pelvic, 3 or 4 from pelvic 

 to origin of anal, and 16 {}) from anal to base of caudal; there appear to be 7 in the 

 upper series; an oblique row of 5 photophores is present on the isthmus, running up- 

 wards to the base of the pectoral fin. Uniformly blackish. 



Described from two specimens, 5810 no mm. in length; types of the species. 



Hab. South of Japan. 



Genus Cyclothone, Goode and Bean 



Goode and Bean, 1883, Bull. Mus. Comp. Zool. x, p. 221 ; Collett, 1896, Bull. Soc. zool. France, 

 XXI, p. 96. 



Close to Gonostoma, but with a small eye; second suborbital not enlarged; prae- 

 maxillary with few teeth; maxillary with a series of small teeth, increasing in size from 

 before backwards, some of them at more or less irregular intervals somewhat enlarged. 

 Dorsal 13 to 15. Adipose fin present or absent. Anal 16 to 20; origin about opposite to 

 that of dorsal. 



About six species. 



I have not attempted a revision of the species of this genus, as my material is quite 

 inadequate. Further, a good revision has been published by Brauer in 1906 (' Valdivia' 

 Tiefsee-Fische, p. 77), and, apart from an important paper by Jespersen and Taning 

 (1926, Rep. Danish Ocean. Exped. 1908-1910, 11, A, 12, p. 7), based on extensive 

 material from the Mediterranean and the adjacent parts of the Atlantic, little has been 

 added to our knowledge of the group since that date.^ 



Cyclothone signata, Garman. 



Garman, 1899, Metn. Mus. Comp. Zool. xxiv, p. 246, pi. J, fig. 3. 

 Hab. Gulf of Panama; Atlantic (?). 



1 Pappenheim (1914, Deutsche Siidpolar-Exped. xv, Zool. vii) has listed a number of specimens of 

 Cyclothone from the North and South Atlantic, but gives no descriptions. See also Roule (1919, Res. Camp. 

 Set. Monaco, lii, p. 27). 



