DISCUSSION OF SPECIES AND THEIR DISTUIKUTION. Ill 



from the caudal base. The fourth aud k)rigest ray nearly eciuals the greatest Height of the 

 body. The distance of the dorsal origin ti-oin the caudal base is contained 5i times in the 

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

 the longest of the ventral rays. The length of the dorsal base is contained Gh times in the 

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

 ray is al)out three-fourths as long as the longest dorsal ray. The caudal lobes in the only 

 specimen 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 outline, which becomes obsolete before it reaches the origin of the anal, and 

 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 the upper series. 



Radial formida: D. 20; A. 24; Y. 7; P. 1+3; C. 17. 



The t.ype of the species is a specimen 160 millimeters long (Catalogixe, No. 37370), taken 

 by the Albatross at station 2565, N. lat. 38° 19' 20", W. Ion. 09° 02' 30", from 2,0G9 fathoms. 



PACHYSTOMIAS, Gunther. 



Echiostoma, sp., Gunther, Aim. and Mag. Nat. Hist., ii, 1878, 180. 



Pachysiomias, Gunthek, Challenger Rejiort, xxii, 210 (type, P. microdon, Guuther, I. c, 210, pi. Liii, fig.c). 



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

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



This genus is known l>y a siiigle s^iecies, rachystomias micrmlon (fig. 134), cai)tured 

 by the Ghallenger at the depth of 2,440 tathoms, to the northeast of Australia. 



BATHOPHILUS, Giglioli. 

 Balhophilus, GiGLiOLi, Pelagos, p. 261, figure, Guntuer, Challenger Report, xxii, 215. 



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

 middle of the length. Head comjiressed; cleft of the mouth very wide; teeth stout. Eye 

 small. Barbel none. Dorsal fin opposite to the anal, which commences behind the vent. 

 Pectoral tins long, \'entrals narrow, inserttd high iqion the side of the triinl: No luminous 

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

 now in the Florence museum. 



EUSTOMIAS, Vaillant. 



Eustomiaa, Vaillant, La Nature, 1884, 85 (name ouly mentioned) ; Exp. Sci. Travailleiu- et Talisman, 1888, 

 112 (type, £. ofcsctioHS, Vaill.).— GCnther, Yoy. Chall., xxii, 204. 



Stomiatids, with anal fin much longer than dorsal and beginning farther forward. 

 "Barbel very elongate. Ventrals composed of two groups of rays. Jaws strongly armei? 

 with teeth in single rows ; teeth absent from palatines, but present ow the tongue. Body 

 entu-ely naked, but with numerous longitudinal luminous dots, and a large luminous body 

 directly behind the eye." ( Vaillant,) 



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



EUSTOMIAS OBSCUKUS, Vaillant. (Figure 135.) 

 Euitamias ohscurus, Vaillant, Exp. Sci. Travaillcur et TaUsmau, 113. pi. iii, figs. 3, 3a. 



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



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

 the lower jaw projects beyond tiie upi)er; the snout half tiie length of the head; mouth 

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

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

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

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



