DISCUSSION OF SPECIES AND THEIR DISTRIBUTION. 89 



This species, first described by Cocco from the Mediterranean, is abundant abont Sicily, 

 but has never before been found in the Atlantic. Tlie descriptions of (Jocco and Bonaparte 

 were too general for use in coiuparisou, also that of (iLiuthcr, beinj;' founded upon a small 

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

 tions of the head and eye peculiar to very yonni;- specimens. 



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

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

 belongs. The three specimens (No. 33.550, U. S. N. M.) described by us, the largest of 

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

 37° 12' 20" N. lat., 6'jo 3'J' W. Ion. These have been studied in connection with ample 

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



DIAPHUS, Eigenmann. 



Diaphus Eigenmann and Eigenmann, Proc. Cal. Acad. Sci., 2d ser., in, 1890, 3. 



Myctopliids, 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 p])i>tophores upon the sides divided into halves by a septum o'f black pig- 

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



The type of this genus is JMaphus fheta, Eigenmann and Eigenmann, loc. cii., from mod- 

 erate depths oft" Point Loma, near San Diego, Cal. (Figure D.'J.) 



Scopelus engrauUs, Giiuther (Challenger Report, xxii, lt)7, pi. Li, tig. c), from 250 

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



TARLETONBEANIA, Eigenmann. 



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



Myctophid fishes, having dorsal and anal fins 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. tciiua, Eigenmann, loc. cit. from near the Corouado Islands 

 (Fig. 105), and M. erenulare, of Jordan and Gilbert, are both Pacific forms. 



RHINOSCOPELUS, Lutken. 



Ahjsia, Lowe, Proc. Zoiil. Soc. London, 1839, 87; Trans. Zoiil. Soc. London, ni, 14. 

 Iihinoscoi)chis, Lutken, Vid. Selsli. Naturv. Copenhagen, vii, 1892, 2.37. 



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

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

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

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

 cnlum, 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. Gill rakers very long and slender. Dorsal fin premedian; pectoral 

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



Precaudals, 2. Snperanals 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, 1 or 2; mediolaterals, 2 or 3; posterolaterals, 1. 



Myclophum cornscans of Ivichardsou, from South Atlantic and Australian oceans, is 

 supposed to belong to this genus. 



