SC0PEL01DS. 
925 
ARGYROPELECUS OLFERSII. 
Fig. 233. 
Length of the maxillaries about equal to the horizontal length of the head Distance between the dorsal fin proper 
and the tip of the snout about half the length of the body , but perceptibly less than the greatest depth of the 
body , which is about s / 5 °f Ls length , and only slightly less than (at least 9 / 10 of) the distance between the ventral 
fins or the anal fin and the tip of the snout. Length of the base of the dorsal fin proper about equal to the 
vertical diameter of the eyes 1 , and the least depth of the tail about 4 / 5 of the said diameter c . Silvery lustre of 
the body extending over the sides of the tail. 
Fig. 233. Argyropelecus Olfersii , natural size. Taken off Haagholm, near Bergen, on the 28th Jan., 1890. 
Specimen in the possession of the Bergen Museum. 
R. hr. 9; D. 9; A. 12; P. 10; V. 6; C. x + 1 + 1 8 d + 1 + x. 
Syn. Sternoptyx Olfersii , Cuv., Reyn. Anim., ed. 2, tom. II, p. 316, 
tab. XIII, fig. 2; v. Dub., Kor., Vet.-Akad. Handl. 1844, 
p. 80, tab. 3, fig. 6; Lowe ( Pleurothyris ), Fish. Madeir., 
p. 64; ( Argyropelecus ), Proc. Zool. Soc. London 1850, p. 
247; Cuv., Val., Hist. Nat. Poiss ., vol. XXII, p. 408; 
Nilss. ( Sternoptyx ), Skand. Fna , Fisk., p. 486; Gthr 
(. Argyropelecus ), Cat. Brit. Mus., Fish., vol. V, p. 386; 
Coll., Forh. Vid. Selsk. Chrnia 1874, Tillasgsh., p. 149; 
1879, No. 1, p. 84; N. Mag. Naturv. Chrnia, Bd. 29, p. 
102; Storm, Vid. Selsk. Skr. Trondhj. 1883, p. 29; Gthr, 
Deep Sea Fish., Chall. Exped., p. 167; Lillj., Sv., Norg. 
Fi.'k., vol. III. p. 3. 
Argyropelecus Olfersii attains, according to Collett, 
a length of at least 82 mm.; but most of the speci- 
mens known are of smaller size. Cuvier’s specimen 
was 68 mm. long. The two specimens that we have 
been enabled to examine — kindly lent us by the Mu- 
seums of Christiania and Bergen — measure, from the 
tip of the snout to the end of the middle caudal rays, 
respectively 63 and 64 mm., being thus about equal in 
size to the specimen described by v. Duben and Koren. 
The species is one of the most singularly shaped 
fishes, deep and compressed as a Dory, but, like its 
congener, with a sharp, posteriorly ascending break in 
the inferior profile between the abdominal region and 
the tail. In the abdominal region the depth of the 
body is about equal to the entire length of the trunk, 
or about 58 — 62 % of the length of the body; whereas 
at the vent the depth is only half of the greatest 
depth, and about equal to the length of the tail. The 
least depth, in front of the supporting (spinous) caudal 
rays, is only about 7 10 of the length of the body. 
The thickest part of the body is the head. According 
to v. Duben and Ivoren, the thickness is greatest in 
the inferior part of the body; but in our specimens 
it is fairly uniform almost throughout the sides of the 
head, measuring across the upper articulations of the 
preopercula about V 8 of the length of the body or 
43 — 46 V 2 % of the length of the head. Both the 
dorsal and the ventral margins are compressed and, 
in part, sharp, the latter, however, from different 
a Somewhat greater or less; in Argyropelecus hemigymnus only about of the said length. 
b In Argyropelecus hemigymnus about 2 / 3 thereof. 
C 1 / •> ' 
5 ? y> ?? / 2 3 ” 
d 17, according to v. Duben and Koren. In Argyropelecus hemigymnus we have counted 16. 
