DISCUSSION OF SPECIES AND THEIR DISTRIBUTION. Ill 



from the caudal base. The fourth aud longest ray nearly equals the greatest neight of the 

 body. The distance of the dorsal origin from the caudal base is contained 5J times in the 

 total length. The longest dorsal ray, which is in the middle of tho fin, is one-half as long as 

 the longest of the ventral rays. The length of the dorsal base is contained Ci times iu the 

 total length. Tlie base of the anal is slightly longer than that of the dorsal, aud its longest 

 ray is about three-fourths as long as the longest dorsal ray. The caudal lobes iu the only 

 specimeu available for study are unequal, the lower one being much longer than the upper, 

 but this may be the result of accident. There are two rows of luminous spots, one close to 

 the ventral outhne, which becomes obsolete before it reaches the origin of the anal, aud 

 another in the lower third of the height of the body, which becomes indistinct about the 

 middle of the total length ; 14 of these spots between the pectoral and the ventral in the 

 lower series and 11 in tho upper series. 



Eadial formula: D. 20; A. 24; V. 7; P. 1+3; C. 17. 



The type of the species is a specimen 160 millimeters long (Catalogue, No. 37370), taken 

 by the Albatross at station L'505, N. lat. 38° 19' 20", W. Ion. G9o 02' 30", from 2,009 fathoms. 



PACHYSTOMIAS, Gunther. 



EchioKtoma, sp., Gunther, Ann. and M.ig. Nat. Hist., ii, 1878, 180. 



Fachi/slomias, GuNTHER, Challenger Report, xxu, 210 (type, P. microdon, Guijther, L c, 210, pi. Llii, fig.c). 



A genus of Stomiatoid fishes, with naked body, normal pectorals, toothless vomer aud 

 maxillaries, and comparatively feeble dentition. Luminous organs large and numerous. 



This genus is known by a single species, PacIiystoiiii((s micnxiou (fig. 134), captiu'ed 

 by the Challenger at the depth of 2,440 fathoms, to the northeast of Australia. 



BATHOPHILUS, Giglioli. 

 Batliopldhis, Giglioli, Pelagos, p. 261, figure, GCnther, Challenger Keport, xxii, 215. 



Body compressed, rather short, scaleless, minutely granulated; vent far behind the 

 middle of the length. Head compressed; cleft of the mouth very wide; teeth st^mt. Eye 

 smaU. Barbel none. Dorsal fin opj)osite to the anal, which commences behind the vent. 

 Pectoral tins long, ventrals narrow, inserted high upon the side of the trunk. No luminous 

 organs ( "?). A single species, B. nigerrimus (fig. 136), taken at Messina by Giglioli, and 

 now iu the Florence museum. 



EUSTOMIAS, Vaillant. 



Eustomias, Vaillant, La Nature, 1884, 85 (name only mentioned); Exp. Sci. Travailleur et Talisman, 1888, 

 112 (type, .E. oftscMCHS, Vaill.).— GOntuer, Voy. Chall., xxii, 204. 



Stomiatids, with anal fin uuich longer than dorsal and l)cgiiining farther forward. 

 " Barbel very elong'ate. Ventrals composed of two groui)s of rays. Jaws sti'ongly armed 

 with teeth in single rows ; teeth absent from palatines, but present oh the tongTie. Body 

 entirely naked, but with numerous longitudinal luminous dots, aud a large luminous body 

 dii'ectly behind the eye." ( Vaillant.) 



A single species, H. obscurtis, from off the Azores, at a depth of 2,792 meters. 



EUSTOMIAS OBSCUEUS, Vaillant. (Figure 135.) 

 Eustomias obscurua, Vaillant, Exp. Sci. Travailleur ct Talisman, li:i, pi. iii, figs. 3, 3a. 



Body elongate; height scarcely one-twentieth of length, and thickness one thirtieth. 



The head, whose length is one-sevonth of the length of the body, is conical, compressed; 

 the lower jaw projects beycmd the ujjix'r; the snout lialf the length of tlie head: mouth 

 very large, although the maxillary does not extend far behind the orbit; the intermaxillary 

 has 2 long, fang-like teeth, and 11 others less conspicuous but strong; the first and the 

 fifth in the latter series are the strongest, the last the smallest. On the maxillary the 

 teeth are visible only with the aid of a magnifying glass; the teeth upon the mandibles are 



