h
73
jfonograj)?! on the AngmllulidDD, or Free Nematoids, Marine, Zand, and Fresli-
i-^fer; icitli Descriptions of 100 New Species. By H. Charlton Bastian, 3r.A.,
}LB. loud., F.L.S.
(Plates IX.-XIII.)
Read December 1st, 1864.
Of the Hclmintlis hitherto described, those belonging to the Nematode group far ex-
ceed in number of species the representatives of either the Trcmatode or the Cestode
orders, and, as far as onr present knowledge extends, they have also a wider distribution
a? parasites amongst the various members of the animal, kingdom. Thus, commencing
with the AcalepJicu, we find the so-called Nematoideum Cydippes taking up its residence
in the substance of the body of one of our smaller jelly-fish, and thence onwards through
higher and diverse types of animal life they are found, in more or less plurality, infesting
rrprescntatives of all the principal orders and classes, till we come to man himself, who
b the chosen habitat of no less than twelve species. Happily, however, whilst thus
numerous and widely diffused, their effects are less pernicious and more seldom fatal
than those rcsultmg from the presence of individuals of the Trcmatode or Cestode types
in their various stages of development \
As regards the actual number of parasitic Kematoids at present known, it has been
computed by Dr. Cobbold, in his recent work on ' Entozoa,' that these do not amount to
more than about 550 distinct species ; and when I mention that within a space of fifteen
months I have obtained from a few limited regions no less than 100 new species of free
Nematoids, some idea may be formed of the numerical importance of this last 'group,
-^Qcernmg which, till within quite a recent period, our knowledge has been so vague
and unsatisfactory.
Bo^ellus^ more than two centuries ago, seems to have been the first to recognize and
(b.a-ibc a member of this family ; and we must look, therefore, upon the so-caUed "Vinegar
^4" whose discovery he announced, as the first known representative of this group of
non-parasitic Nematoids to which I refer. The same animal was subsequently seen by
^o^er, Hooke, Leeuwenhock, Baker, Spallanzani, and other pioneers of microscopical
iBsearch, who soon found a companion for it in its near ally, the -Paste Eel." Then came
"le discovery by Needham^ in 1743, of the wonderful Vihrio tritici and its young so
•^ligely tenacious of Ufe ; and afterwards Otto MiiUer^ was followed in his recognition of
As exceptions to this general rule, three Nematoids may be cited ^vhich are undouhtedlv most serious pests to the
V
nea\V
--.^...., .. .uexr occurrence and the serious diseases to which they give rise : these are the
Mrtiril! ""' ""^'"^ '' '" prevalent in the tropical parts of Asia and Africa; Scleroslomum duodenale, principally
th m Egypt, and so common that Dr. Griesinger considers about one-fourth of the whole population suffer more
«uaiion • V *-'^ "" fluorosis" (a malady that is frequently tatai;, aue lu tuc ^.^...... «. .^^.^ i^-.--^
' Oba J^^^ trichuiosis, in various parts of Germany more especially,
• "»^croscop. Centur. ;, 165G. ^ jyjj^^ 99^ j^t. v. 7. * Animal. Infusoria. 4to. Ilamb. 1786.
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