DISCUSSION OP SPECIES AND THEIR DISTRIBUTION. 211 



former with 3 or 4, the latter with 2 or 3 spines; caudal deeply forked; ventrals thoracic, 

 with onc*spiue and five rays. The jaws with an outer series of stronger teeth; the teeth of 

 the palatine bones and of the vomer are easily lost. Opercles entire. Seven branchios- 

 tegals; air bladder, none. Pyloric appendages in small number. {Gilnther.) 



A very elaborate study of Brama has been completed by Liitken, based upon a large 

 series, chiefly of young specimens. Concerning B. Baii he concludes that it is quite cosmo- 

 politan in its distribution, occurring from the Faroe Islands to the Cape of Good Hope, 

 and is represented by closely similar, if not identical, forms on the coast of Chili (B. 

 chileims and amtralis) and New Zealand [B. squamosa) and in the waters of Japan. He 

 states that it has not yet been found in the West Indies or off the east coast of North 

 America, overlooking, perhaps, the fact that Brama Baii was observed at the Bermudas in 

 1880 by Dr. Goode. He considers B. orcini and B. Dussumieri and Taractes asper to be im- 

 mature forms and gives a very doubtful acceptance to six species, claiming to be distinct 

 from B. Bail, described from various parts of the Atlantic : 



Brama A(iassizii, Poey (Mem. Hist. Nat. Cuba, ii, 1856-8, 204). Cuba. 



Brama Brevoorti, Poey (loc. cit., 206). Cuba. 



Brama Satissurii, Liinel {Revision, etc., 185, pi. ii). Cuba. 



Brama longipinnis, Lowe (Proc. Zool. Soc, 1843, 82). Madeira. 



Brama pmiceps, Johnson (Proc. Zool. Soc, 1863, 38, pi. vii). Madeira. 



Brama Easchi Esmark (Forh. Vid. Selsk., Christiania, 1861). Finmark, Iceland. 



Serious discussion of these forms can not well be attempted without a large series of 

 specimens of all ages. In the meantime, it is most convenient to consider all the Atlantic 

 forms as members of a single species, quite variable in the proportions of the body and the 

 fins. 



B. japonica, Hilgendorf, has tlie snout more convex than B. Raii, shorter vertical fins, 

 and smaller jiaired fins, and the lesser size of the scales in the axils of the pectorals. 



Family DIRETMID^^. 

 Diretmida', Gill, MS. 



Scombroideaus with a disciform body (suggestive of Priacantlms) preoperculum pro- 

 longed downward and separating the operculum from other bones; supramaxillaries wide 

 behind; a long dorsal and anal with simple (?) rays, and ventrals thoracic. {Gill). 



DIRETMUS, Johnson. 



Diretmus, Johnson, Proc. Zocil. Soc. Loud., 1863, 403. 



Discus, Campbell, Trans. New Zeal. lust., xi, 1879, 297. 



Gyrinomene, Vaillant (name onlj-), Exp, Sci. Travaillcur et Talisman, 1887, 355, 18. 



Body much compressed, short and elevated, covered with small, coarsely spinous scales, 

 on which no lateral line can be traced ; abdomen prominent and keeled. Mouth wide, ob- 

 liquely ascending, with projecting lower jaw. The jaws are armed with a very narrow 

 band (which, posteriorly, becomes a single series) of small tine teeth of unequal size. The 

 vomer and palatine bones are toothless. The maxillaries terminate at their upper and in- 

 ner extremity in a pair of short-pointed processes, which form peculiar fang-like projections 

 in the inside of the mouth in front of the vomer. Bones of the head thin, with wide, mucif- 

 crous cavities, the lower limb of the preoperculum denticulated. Eyes very large. Dor- 

 sal long, without spinous di^^sion ; anal similar in form and composition ; interradial mem- 

 brane very fragile. Pectorals large; ventral fins thoracic, with more than 5 rays (?). 

 Branchiostegals 7 ; pseudobranchia?. {Giinther.) 



DIRETMUS ARGENTEUS, Johnson. (Figure 234.) 



Diretmus nrgenteus, Johnson, Proc. Zool. Soc. London, pi. xxxvi, fig. 1. — Vaillaxt, loc. cit., 355. 



'The specimen from Madeira, described in detail and well figured by Johnson, was the 

 only one known until the French expedition obtained another ott" the coasts of Morocco in 

 1,105 meters. Johnson ascribed to it, although with doubt, 10 ventral rays, but the rays 



