DISCUSSION OF SPECIES AND THEIR DI8TRIB1 Tlo.V. 89 



This species, first described by Oocco from the Mediterranean, is abundant about Sicily. 

 but has oever before been found in the At Ian tic The descriptions of Cocco and Bonaparte 

 were too general for use in comparison, also thai of Giinther, being founded upon a small 

 number of very minute specimens, especially as it lias few rays in the anal and the propor- 

 tions of the head and eye peculiar to very young specimens. 



It is with peculiar pleasure that we add to tlie fauna of America a species identified 

 with the name of Rafinesque, who was the first to call attention to the genus to which it 

 belongs. The three specimens (No. .'i;r>.">o, U. S. K M.) described by us, the largest of 

 which is 77 millimeters long, with imperfect tail, were taken by the steamer Albatross in 

 37°12'20" N". lat., 69 39' W. Ion. These have been studied in connection with ample 

 material from Messina (No. 40058, U. S. N. M.), received from the Florence Museum. 



DIAPHUS, Eigenmarm. 



Diaphun EIGENMANN and Eigenmann, Proo. Cal. Acad. Sci., 2d ser., in, 1890, 3. 



Myctophids, similar in form and proportions to the typical genus of the family, though 

 stouter, with a very much wider and less oblique mouth, pectoral placed lower, and with 

 opercular apparatus much more obliquely articulated. Dorsal and anal similar, not touch- 

 ing the same vertical. The glandular photophore in front of each eye below the nostril, and 

 the pearl like photophores upon the. sides divided into halves by a septum of black pig- 

 ment. No caudal photophores. Postlaterals, 2, in obliquely ascending row. 



The type of this genus is Diaphus theta, Eigenmann and Eigenmann, he. cit., from mod- 

 erate depths off Point Loma, near San Diego, Cal. (Figure 93.) 



Scopelu* engraulis, Giinther (Challenger Eeport, xxn, 107, pi. li, tig. c), from 250 

 fathoms off the Philippines, is referred to the same group by Eigenmann. 



TARLETONBEANIA, Eigenmann. 

 Tarletonbeania, Eigenmann and Eigenmann, Proc. Cat. Acad. Sci. (2d ser.) iii, 7. (1S90). 



Myctophid fishes, having dorsal and anal tins considerably overlapping, the base of 

 the anal much longer than that of the dorsal. Lateral line obsolescent. Head long, with 

 oblique opercular limb. Pectoral very high. No luminous glands. Photophores much as 

 in typical genus, but none to be detected upon the head. One precaudal photophore. 



The type of this genus, T. tenua, Eigenmann, he. cit. from near the Coronado Islands 

 (Fig. 10.j), and M. crenulare, of Jordan and Gilbert, are both Pacific forms. 



RHINOSCOPELUS, Lutken. 



dlysia, I. owe. Proc. /..>,,]. Soc. London, 1839, 87; Trans. Zool. Soc. London, in, 14. 

 Rhinascopelus, LTtkex, Vid. Selsk. Naturv. Copenhagen, vn, 1892, l>:;t. 



Body oblong, slender, compressed, with slender and elongate caudal peduncle cov- 

 ered with smooth, stiff scales, those in the lateral line much longer than the others. Head 

 compressed; cleft of mouth very wide; the, jaws about equal. The premaxillary long and 

 slender; maxillary well developed, reaching nearly or quite to the angle of the preoper- 

 culuin, without considerable posterior dilation. Teeth in villiform bands in the, jaws, on 

 the palatines, pterygoids, and tongue. Eye moderate, its diameter less than one-third of 

 the length of the head. < 1 ill rakers very long and slender. Dorsal fin premedian ; pectoral 

 large; adipose dorsal small. Anal fin longer than dorsal. Pectoral narrow, elongate. 



Precaudals, 2. Superanals about 18, in two groups, the break being over the middle 

 of the long anal fin and at* the end of the first third of the series, approximately. Antero- 

 laterals, i or 2; mediolaterals, 2 or 3; posterolaterals,!. 



Myctophum coruscans of Richardson, from South Atlantic and Australian oceans, is 

 supposed to belong to this genus. 



