DISCUSSION OF SPECIES AND THEIR DISTRIBUTION. 87 



which is represeuted by the most anterior of the si'<JiiP) which is phiceil over the axil of the 

 ventral and about three-fourths of the way from its root to the lateral line; a fourth photo- 

 phore, possibly also to be grouped here, is nearly midway between the axil of the pectoral 

 and the axil of the dorsal. Radial formula: 1). Ill, 13; A. Ill, 14; L. lat. 40. 



This species has been found only in the Meiliterraneau. Raffaele had six specimens from 

 Messina, and Giglioli obtained two others from the same locality in the latter part of Sep- 

 tember, 1878, one of which, presented by him to the National Museum (Cat. 44169), is the 

 type of the foregoing description. The species seems to be exceedingly rare, even in the 

 Mediterranean. The great extension and elaboration of the nasal luuunous plate shown in 

 the ligure, may be due to sexual conditions. At all events, as has been remarked, it is 

 unlike that shown by Eafiaele, though sufliciently similar to that of Cocco and Bonaparte. 



^THOPRORA LUCIDA, Goode anil I'.eax, n. s. (Figure 102.) 



Height of body contained 4i times in total length; length of head 3§ times. Least 

 depth of tail 2^ in height of Ijody. Head considerably longer than high, its height equal to 

 distance from anterior margin of pupil to end of opercular flap. Eye moderate, its diameter 

 nearly one-fourth length of head. Snout short, but less declivous and obtuse than in 

 A. vietopoclampa. A pearl-colored luminous organ touching the limb of orbit, but separated 

 from it above and below, witli posterior lobe not prolonged far back, and with a space 

 between its lower margin and the opening of the Jaw. Cleft of mouth oblicpie and curved, 

 the maxillary reaching to angle of preoi)erculum and not dilated. Origin of dorsal and 

 ventral nearly in same vertical, that of former midway between anterior margin of orbit 

 and adipose ttn; that of latter nudway between tij) of snout and adipose fin. Insertion of 

 the last ray of dorsal is over interspace between third and fourth rays of anal. Pectoral 

 (unless mutilated) only half as long as ventral, and its tip does not approximate the vertical 

 from its origin. Dorsal and anal similar, the former with its ui)p('r margin concave. Adi- 

 I)ose dorsal inserted over interspace between antcpenultiu.ate and penultimate anal rays, 

 and as long as ultimate dorsal ray. Scales smooth, those of lateral line scarcely enlarged. 



In the type there are thirteen photophores in the anal series; a wide break over the 

 roots of the last two rays of the anal tin. No posterolaterals. Two mediolaterals, the 

 anterior the lowest. Two anterolaterals, the anterior and highest very small, above the axil 

 of the pectoral or very near the lateral line, the posterior one somewhat more than midway 

 between this and the anterior of tlie mediolateral group, and forming, with the two photo- 

 phores in that group, an obtuse isosceles triangle, witli the anterior of the medial group at 

 its apex. Of the four precaudal photophores the last three are the most nearly together, 

 and form a nearly vertical line at the base of the lower caudal lobe. There is a large, 

 apparently luminous, pearl-colored spot under the tip of the flap of the operculum. 



Kadial tVunuila: D. Ill, 14; A. II, 14; L. lat. 35. 



A single specimen (Cat. No. 44081, U. S. N. M.), about 4 inches long, was obtained by 

 the Albatrons at station 2127, in Id'^ 4.")' N. hit., 75'= 04' W. Ion., l,f)3!» fathoms. 



^THOPRORA EFFULGENS, Goode and Bean, n. s. (Figure 103.) 



Height of body one fourth of total length, length of head slightly greater. Least depth 

 of tail one-half height of body. Head considerably longer than high, the flap of opercu- 

 lum extending above and behind axil of pectoral. Eye large, diameter contained 2i times 

 in length of head. Snout exceedingly short and obtuse, as in A. metopodampa; the 

 luminous organ enormous, gland-like, overlapping entire anterior margin of orbit, extend- 

 ing down upon edge of jaw and extending backwards almost as far as in A. metopoclanipd. 

 Cleft of mouth oblique, somewhat curved, the maxillary reaching nearly to angle of pre- 

 operculum. Origin of dorsal somewhat in advance of vertical from that of ventral, which 

 touches root of second dorsal ray. Last dorsal ray over roots of short spines ])re(cding 

 anal. Insertion of ventrals considerably posterior to a point equidistant from root of adi- 

 pose dorsal and anterior margin of the orbit. Origin of adipose dorsal over interspace be- 



