[89] MATERIALS FOR A HISTORY OF THE SWORD-FISHES. 377 
short, and compressed. The smaller they are the broader and shorter 
the snout is, until at last its length is not greater than one eye-diameter. 
The preopercular spine in all of them is much longer than the short pec- 
torals. The ventrals appear only as the least little rudiment. Like the 
larger example, all have one or two small spines below, two above, the 
preopercular spine (of which spine nothing is seen in Figs. 1 and 2, p. 
443). The dorsal and anal fin in all of them is low, without evident 
rays, even if such are present in the caudal; in the younger one is seen 
very plainly the notochord curved upward at a right angle, but in the 
smallest of all (Plate I, Fig. 11) it is not yet curved upward, and all 
three fins are connate; in the very earliest stage of development of 
Histiophorus is seen finally, as in certain other young Scombroids, a 
little supraorbital spine, but it disappears comparatively early. 
Of Xiphias gladius Cuvier has described and figured the younger stages 
of 12 and 18 inches; Plates 225 and 226 of the great ichthyological work 
are in this respect exceedingly instructive. Young forms of 124 millime- 
ters and 24 inches are mentioned by Giinther (/. ¢.), who has given a brief 
account of their differences from the very young Histiophori. One may 
obtain from these data alone a very good idea of the history of the 
development of “the common Sword-fish”. There are before me, besides 
young Sword-fish of 27 and 414 inches (to the cleft of the caudal), a 
specimen 190 millimeters long found in the stomach of an albicore, but 
tolerably well preserved, besides the series of smaller specimens from 10 
to 46 millimeters long.* In the young Sword-fish of 27 inches t the keel 
is present on the tail; the gills have the Xiphias character, but the dor- 
sal is single, continuous; likewise the anal; and the skin is now rough 
from the close covering of rough scales, which will be immediately 
described more fully in a younger example, and between which the 
four series of large, pointed bone-bucklers on each side are now very evi- 
dent. Ofthe smaller, pelagic specimens the largest (190 millimeters) 
and the smallest (10 millimeters) are especially interesting; this last 
because it is so much smaller than any hitherto described, and makes it 
possible to give a representation of the appearance of the genus ata 
very considerably earlier stage of development, and at the same time to 
*The places where these young Sword-fish were caught, so far as recorded, are the 
following: 38° 53’ N. lat., 19° 37’ W. long.; 32° 50’ N. lat., 74° 19’ W. long. ; 23° N. 
lat., 55° W. long. ; 20° N. lat., 319 W. long.; 0° N. lat., 29° W. long. ; 25° 4’S. lat., 
27° 26’ W. long. Indian Ocean: 21° 30 W. iste, 57° 50! E. long.; 22° S. lat., 57° 40’ E. 
long. ; 23° 40’ S. lat., 57° 40’ E. long. 
a comparison W ith the measurements of the example 190 muillamerer rs iong, I give 
some measurements of the 27-inch Sword-fish : 
Inches. 
HE CrVELS SOLE So) Ta ey a ae PEL Ser 2 he 2g 12 
Heiehtiot body behind! the head... 3.2.5.5... 4.c2e taste ens+) ate sneees 6-22 2se-- 3h 
Length of dorsal ray near the middle ot the backee mes ee. acces. - nice eeees ces . 2b 
Monctiner peciinmliae: 2 os See oat sk SSS RUT Fete Bn Fo Ske ~ b's siSdale iene diee stb es 4 
Lower jaw (5} inches shorter than upper jaw).----- .--.-------------++e---2 eee 5 
From the front margin of the eye (socket) to gill-opening ...--..---.------------ 3k 
