[55] MATERIALS FOR A HISTORY OF THE SWORD-FISHES. 343 
ceans remotely resembling crabs and lobsters, which attach themselves 
to the gills and skin of many kinds of fishes, sucking the blood from 
their veins, and often causing death; dreadful to their victims as was 
their namesake, the fabled Lernean Hydra, to the Argives of old, and 
not to be destroyed by any piscine Hercules and Iolaus. 
In one of the early volumes of the Philosophical Transactions is an 
account by 8S. Paulo Boccone of ‘an extraordinary Sanguisuga or Leech, 
found sometimes sticking fast in the Fish called Xiphias or Sword-fish”” 
It is described as “about four Inches long, the Belly of it white, carti- 
laginous and transparent, without Eyes or Head, but instead of a Head 
it had a hollow Snout, encompassed with a very hard Membrane ; which 
Snout it thrusts whole into the Body of the Fish, as strongly as an 
Augre is wound into a piece of Wood, and fills it full of Blood into the 
very Orifice”. He names it “‘ Hirudo or Acus cauda utrinque pennata”.* 
A specimen taken off Seaconnet, July 22, 1875, had fluke-worms in the 
external coat of the stomach and in the air-bladder. 
I am indebted to Mr. Frederick W. True for the following account of 
the parasites of the Sword-fish : 
_ The Sword-fish is infested by many species of parasites. Some hang 
on the gills, others fasten themselves to different parts of the alimentary 
canal—the cesophagus, the stomach, and the intestines—and others, 
still, bore into the flesh. Several species, as might be expected from the 
size of the fish, are among the giants of their races. All undoubtedly 
cause more or less pain to their host, but especially those which attach 
themselves to the gills, disturbing their action and destroying their sub- 
stance. 
The parasites of the Sword-fish, for convenience, may be classified in 
two groups, the Worm-like parasites (Helminthes) and the Crustacean 
parasites. 
a. The Worm-like parasites (Helminthes)—Seven species of Helminthes 
from the Sword-fish have been described, of which one belongs to the 
group Nematoda, or Round-worms, four to the Trematoda, or Flukes, 
and two to the Cestoda, or Tape-worms. 
NEMATODA. 
1, ASCARIS INCURVA, Rudolphi. 
Ascaris incurva, RUDOLPHI, Entozoorum Synopsis, 1819, pp. 51, 292.—DuJaR- 
DIN, Hist. Nat. des Helminthes, 1845, p. 203.—DirsinG, Systema Helmin- 
thum, ii, 1851, p. 163.—ScHNEIDER, Monographie der Nematoden, 1866, p. 
48, pl. ii, tig. 11.+ 
“ The | Philosophical | Transactions | and | Collections | To the End of the Year 
MDCC | Abridged | and | Disposed under General Heads | —— | Vol. II | —— | Con- 
taining all the | Physiological Papers | —— | By John Lowthorp, M. A. and F.R.S. | 
— | The Fourth Edition | iondons erie lp MDCCXXXI, p. 821.) 
t This synonymy does not profess to be complete. Reference is given only to the 
authority in which the original description occurs, to one or two later ones giving an 
accurate description, and to one in which the species is figured. 
