DISCUSSION OF SPECIES AND THEIK DISTRIBUTION. 127 



passage through the surface strata; and I am very much inclined to think that the latter 

 took place We have very little positive information as to the habits of these fishes, but 

 we know that they arc commonly obtained near the surface in mid ocean; and from their 

 structure ;vc may infer that, like all deep, compressed fishes, they are slow swimmers, and 

 that they can with ease maintain a free position in the water, without the necessity of a 

 support, remaining as it were at a certain distance from the surface. This may be observed 

 iu a lish of our own seas with a similar elevated body, viz, the John Dory, in which, how 

 ever, a rapid andulatory movement of the soft dorsal tin is almost unceasing. The great 

 development of the luminous organs, combined with the large eyes, indicates the nocturnal 

 habits of the fish, which would induce it to descend to a greater depth during the day- 

 time. Also the firm structure of the bones disproves the bathybiaJ habits of Argyropelecus." 

 The following specimens have been obtained by the steamer Albatross: < at. No. 33296, 

 U. S. N. M., from station 2043, in 39° 40' N. lat., 68° 28' 30" W. long., at a depth of 1,467 

 fathoms; Cat. No. 33393, U. S. N. M., from station 2075, in 41^ 40' 30" N. lat., 66° 3,V W. 

 long., at a depth of 855 fathoms; Cat. Ni . 33495, U. S. N. M., from station 2063 in 42=> 22' 

 N. lat., 00° 23' W. long., at a depth of 144 fathoms; Cat. No. 33500, IT. S. N. M., from sta 

 tion 2101 in 39° 18' 30" N. lat., 68° 21' W long., at a depth of 1,680 fathoms; Cat. No. 35467, 

 U. S. N. M., from station 2195 in 39° 44' N. lat., 70° 03' W. long., at a depth of 1 ,058 fat horns; 

 Cat. No. 355J ',4, IT. S. N. M., from station 2208 in 39° 33' 71" N. lat,, 16° 15' W. Ion-., at a 

 depth of 1,178 fathoms; Cat. No. 35561, IT S. N. M., from station 2209, in 39° 34' 45" N. lat., 

 71° 21' 30" W. long., at a depth of 1,080 fathoms; Cat. No. 38211, U. 8. N. M., from station 

 2728, in 36° 30' N. lat., 74° 33' W. long., at a depth of S59 fathoms; Cat. 43855, IT. S. N. M., 

 from station 2717, in 38° 24' N. lat., 71° 13' W. long., at a depth of 1,615 fathoms (Sp. nova ?) ; 

 and a specimen from station 2505, in 38° 19' 20" N. lat., 69° 02' 30" W. long., at a depth of 

 2,009 fathoms. A single specimen was obtained from the Grand Banks by a- Gloucester 

 fisherman. 



ARGYROPELECUS D'URVILLII, Cuvier & Valenciennes. 



Argyropelecus d'Urvillii, Cuvieh &, Valenciennes, Hist, Nat. Poiss., xxn, 405. — Gunthek, Cat, Fish. Brit. 

 Mus., v. 1864, 386. 



The height of the body ecpials the distance between the gdl opening and the root of the 

 caudal; tail much higher at its base than in A.hemigymnus; mandible without prominent 

 spine at its posterior corner; angle of the preoperculum with a spine directed downwards; 

 tail without spines. The pectoral fin does not extend to the hind margin of the trunk. 

 ( Valenciennes.) 



Eadial formula: B. 9; D. 9; A. 10; P. 10; V. 0. 



This form is known only from mid-Atlantic; it may possibly yet be found to be identical 

 with A. hemigymnus. 



ARGYROPELECUS ACULEATUS, Valenciennes. 



Argyropelecus aculeatus, Cuvier & Valewciennes, Hist. Nat. l'uiss., xxn, 406.— Gunthek, Cat, Fiah. Brit. 



Mus., v 1864, 386. 

 Argyropelecus acanthurus, Cuvier & Valenciennes, loc. cit., 40*. 



The height of the body equals the distance between the posterior margin of the pre- 

 operculum and the root of the caudal: ail very slender. Mandible with a very obtuse 

 spine, at its posterior corner; preoperculum with a spine directed downwards. A double 

 row <>f spines along the lower side of the tail. ( Valenciennes.) 



B.9; D. 9; A. 14; P. 10; V. 7. 



'l'h is form has only been found at sea off the Azores. It may probably prove to be a form 

 of one of the better-known species. 



STERNOPTYCHIDES, Ogilby. 



Sternoptyehides, Ogilby, Proo. Linnaean Society, NVu South Wales (2d ser. i, hi, 1313, 1X88. 



"Pseudobranchiae present; head and trunk much elevated and compressed, the latter 

 passing gradually into the moderately long pedicle; the margin of the upper jaw formed by 



