nemathelminth 
nemathelminth (ncm-a-thel'minth), a. andn. nematode (nem'a-tod), a. and n. [< Gr. 
I. ii. Of or pi rlainiiig to the Xanttthelmintheg. rubric, thread-like: see nematoid.] 
Also iifintillii-liHiHlliii: Hi-matoid. 
II. n. A member of the yematlielminthes. Nematodea (nem-a-to'de-a), n.pl. [NL., < Gr. 
Nemathelmintha (nem'a-thel-min'thtt), n.pl. vmmrw-V, , thread-like: tee nematoid.} Same as 
[NL.] Same as Si'inathelmiiithes. .\i-miitoiilm. 
Nemathelminthes (nem'a-thel-min'thez), n. Nematodonteae (nem'a-to-don'tf-S), n. pi. 
Nematopoda 
III. [NL.,< dr. vijua (vi/fiar-). thread, 4- 
' ' 
[NL., < Gr. vrjfta (vy/iar-), a thread, 4- 
pi. [JNLi.,\ Ur. vr/ua (vqfUtr-). inroaa, -r ef.iuv<; Lf**J-i * ur - W V^f^/i B l " IBU .i ,\ "'"" 
(ii/iivli-), worm.] A class of Vermes, including (ooWr-), = E. tooth, + -.] A division of 
nematoid worms and certain related forms ; the 
roundworms or threadworms. They are round or 
cyllndrlc worms, sometimes extremely slender and filiform 
or thread like, from less than an inch to several feet In 
mosses in which the teeth of theperistome are 
not _provided with transverse septa : opposed 
to the Arthrodontete, in which the teeth are 
very minute size. Some are parasitic in the larval state, 
and free when adult ; in others this is reversed. The body 
is not truly seKinental though the cuticle may be ringed. 
The class is chielly made tipof theXmiatmdea: Itlncludes, 
however, the Acanthvcephala (Kchinarhynkida), and for- 
meriy the cii<rt<ntHi (Xuifitta) were 
* ., " , ___ 
,, - T .- . [< NL. nemato- 
i/i tin.i: see wmatogi'iuiHH. \ I lie vermiform i-m- 
bryo of a nematoid worm; one of the phases 
or stages of nematoid embryos: opposed to 
._ rhombogen. See cut under Dicyema. 
, ., ,__ __J added. The term Nematogena (nem-a-toj'e-nil), n. pi. [ML., 
i Is sometimes used synonymously with NemaMdea. See neut. ph of nematoyenus : see nematogenous.] 
\-uts under A>rwtoiJa, Aamthocephala, and Sayiaa. Th nematogenous Dicyemida which give rise 
nemathelminthlC (nem'a-thel-mm thik), , a. ^ vermi f orm embrvos. as distinguished from 
[< nemathelminth + -tc.] Same as nemathel- 
minth. 
NematistiidsB (nem'a-tis-ti'i-de), n. pi. [NL., 
11,1 + -Ida:'.] A family of acanthop- 
terygian fishes, represented by the genus *ema- 
and the month obliquely cleft; the eyes are lateral and the 
opercular bones unarmed ; there are 2 dorsal fins, the first 
with 8 spines, most of which are elongate and filamentous ; 
the anal Is moderately long, with 3 spines ; the ventrals 
vermiform embryos, as distinguished 
Itliombigena, which produce infusoriform em- 
bryos. See cut under Dicyema. 
(nem'a-to-jen'ikV a. Same as 
. Kncyc. Jirit., XVIII. 259. 
(nem-a-toj'e-nus), a. [< NL. 
producing: see -gen.] Producing vermiform 
embryos, as a nematoid worm ; having the char- 
acters of a nematogen. 
have a spine with 5 rays, the innermost of which is com- 
posed of many parallel branches ; and the caudal is furcate. 
Nematistius (nem-a-tis'ti-us), n. [NL., prop. 
* Xemathistius, < Gr. vf/ua (vrjfiar-), thread, + ta- Nematoglossata (nem'a-to-glo-sa'tii), n. pi. 
roc., web: see histoid.] The typical genus of [NL.] Same as Nemoglossata. 
Nematistiidai, so called from the thready ex- nematognath (nem'a-tog-nath), a. and n. [< 
tension of the spines of the first dorsal fin. NL. nematoynathus, "<. Gr. vrjua (vtjfiar-), thread, 
There is only one species, N. pectoralis. + -piAHof, jaw.] I. a. Having barbels on the 
nematoblast (nem'a-to-blist), n. [< Gr. vf/fia jaws, as a catfish ; specifically, of or pertaining 
' , a germ.] Same as to the Nematognathi. 
n. n. A member of the Xematognathi ; any 
catfish. 
Thus the nematagenma Dicyema gives rise by a gamo- 
genetic process to new Dlcyemas. 
Huxtey, Auat. Invert., p. :**>. 
r-), a thread, 
spermatoblant. Sertoli. 
nematocalycine (nem*a-to-kari-sin), a. 
[< 
nematocalyx (-calyo) + -in* 1 .] Pertaining to Nematognathi (nem-a-tog'na-thi), n.pl. [NL., 
or having the character of a nematocalyx. pi. o f "nematognathus: see nematognath.] An 
nematocalyx (nem^a-to-kaMiks), n.; pL *MM- order of teleost fishes in which the supramax- 
tocalyxex, nematocalyces (-ka'lik-sez, -kal'i-sez). -" * '- 1 ' J - 1 k j - 
[NL.,< Gr. vtjfta (vr/fiar-), thread, + /cdAuf, calyx : 
see calyx.] A calyx of some hydrozoans, as 
Plumulariidce, containing nematocysts. 
Nematocera (nem-a-tos'e-ril), n. pi. [NL., 
neut. pi. of nematocerHn: see nematoceroiis.] A 
suborder or section of Diptera, containing the 
numerous insects known as gnats, midges, mos- 
quitos, crane-flies, gall-flies, etc. : so called from 
the long thready antennae. These organs are usu- 
ally many-]olntd, with from 6 to 16 joints, most of which 
illary bones are lateral and short or rudimen- 
tary, and covered with skin which forms bar- 
bels at each corner of the mouth, whence the 
name ; the nematognaths or catfishes. The in 
termaxillarles are closely apposed to the ethmoid and im- 
movably fixed ; there is no subopercnlar ; the four ante- 
rior vertebra are coalesced Into a single piece ; and ele- 
ments are detached to form bones which connect the air- 
bladder with the organ of hearing. Nematognaths have 
no true scales ; they are either naked or have appendages 
developed as plates on all or a part of the body. About 
800 species are known ; they are specially numerous in 
See cuts under Silurulce and 
proper and Loricartidce. 
Loriearia. 
nematognathous (nem-a-tog'na-thus), a. [< 
da; one of the organs of offense and defense 
horn : see eerax."] Having long or thready an- 
tennte, as a dipterous insect ; of or pertaining 
to the Nematocera; nemocerous. ,____. _ ^ -- , - 
nematocvst (nem'a-to-sist), n. [< Gr. i%a (vr,- NL. * iiematognathus.} Same as nematognath. 
liar-), a thread, + /t'iW.f , bladder, bag: see cyst.] nematoid (nem'a-toid), o. and n. [< Gr. ?- 
A thread-cell or lasso-cell ; a cnidocell or cni- /*aroti%, eontr. vrntarMiK, thread-like, thready, 
fibrous, filamentous, < vijfia, (vr/juiT-), thread, + 
e!o<,-, form.] I. a. Thread-like, as a worm, (o) In 
206]., nemathelminth; of or pertaining to the Ntinalui- 
dea. (6) In mycol., thread-like or filamentous: applied to 
the hyphas or mycelium. 
EL. n. A threadworm, hairworm, round- 
worm, or pinworm. 
Also nematode, nemaMdcan. 
Nematoidea (nem-a-toi'de-S), n. pi. [NL.: see 
Xematoda.] An order of kcmathelminthfs, or 
class of Vermes, having a mouth and an alimen- 
tary canal and separate sexes, and being usual- 
ly parasitic ; the nematoid worms ; the round- 
worms and threadworms. The name was introduced 
by Rudolphl for worms previously known under the name 
of Ascaride*. a term afterward used in a much restricted 
sense. Most of these worms are endoparasilic at one or 
another stage of their life orduring the wholeof It; those 
which are not are mostly of minute size. There are several 
distinct families, and most of them have popular names. 
Thus, the AscaridtK contain the roundworms and pinworms 
of the human rectum. The Stmngylidrr. or strangles are 
parasites of various parts of the body, like the Triehinitltr 
or measles of pork. The FHariidae are the guinea-worms. 
The Oardiidcf are the horsehair-worms, found in ponds 
and brooks and In the bodies of Insects. Angviuulidcc 
are the little creatures known as vinegar-eels. Some 
nematoids are marine. In Cuvier's system, in which the 
Nematoidea are the first order of Entozoa, they included 
the lerntean crustaceans. In a late arrangement they are 
made the fourth phylum or main division of ixelomatous 
Tentacle and Nematocysts of Athorybia. 
I. tentacle, with A, peduncle ; B, involucmm of C, the sacciilus. 
with Z), its filaments; a, ectoderm ; e, endodenn ;/,/,/. nematocysts; 
2. two separate nematocrsts, enlarged, the lower one a, with its fila- 
ment t , projected from the sheath . 
peculiar to coelenterates, as 
jellyfishes, by 
See cuts under 
means of which they sting. 
fniilii, Artiiin:<Mt, and Ifillxin. 
nematocystic (nem''a-to-sis'tik), a. [< nemato- 
ciixt + -if.] Pertaining to or having the char- 
acter of a nematocyst; cuidarian. 
Neraatoda (nom-a-to'da), n.pl. [NL., irreg. for 
\finn tuili'ii, \<-m<i<<>i<trti : see nematoid.] Same 
as Xenuitoidea. 
animals, and divided into three classes, called Ewnema- 
toidta, Ckatotamaria (with genera C/iirtotnma and Kliab- 
doya*Ur\ and Clurtnynatha (Sagitta and SpadeUa). Also 
Xrmatoda, Xrmatodea. Srmatodet, Xnnatouta. See cut in 
next column, and cut* under Oxyurit, t'iiaria, and Ckmtiiu. 
A Threadworm (AHf*ill*la brevt'tfirtui*. 
I. male; II, female; III, female genital orgmns; IV, seminal corpus- 
cles. A, anus ; A unicellular cutaneous glands at anal end ; /", fatty- 
looking gland ; G, sexual aperture ; S. seminal corpuscles ; T, testis ; 
, esophagus; a', chitiniled oral capsule; c. gastric, and 4 rectal 
parts of alimentary canal ; r. ? . anterior and posterior thickenings 
wilh their commissures : Of, ovarium ; r, dilatation of uterus, serring 
as a receplaculum seminis. 
nematoidean (nem-a-toi'df-an), a. and n. [< 
Xematoidea + -an.] Same as nematoid. 
Nematoneurat (nem'a-to-nu'rii), n. pi. [NL., 
< Gr. vijpa (vT/ftar-), a thread, + vevpov, a sinew, 
nerve : see nerve.] A division of animals pro- 
posed by Owen for the higher Itadiata of Cuvier, 
in which a nervous system is apparent. The 
group included the echinoderms, rotifers, poly- 
zoans, and co?lelminths. 
nematoneurous (nem'a-to-nu'rus), a. Of or 
pertaining to the Xematoneura. 
Nematophora (nem-a-tof 'o-r&), n. pi. [NL., < 
Gr. vfifui (vrifiar-), thread, + -^"pof, s Qtptiv = E. 
bear 1 .] A prime division of Coelentera, con- 
taining all those which have thread-cells or 
stinging-hairs ; the nematophorans ; nematoph- 
orous coelenterates, or Cnidaria': distinguished 
from Porifera or sponges. The name Is a synonym of 
Ctrltntera In the usual ana current sense of that term, as 
covering the Anthozoa, Hydrozoa t &ndCtenophora. In some 
arrangements, as that of . R. Lankester, AematapharaKie 
a prime division or phylum of animals, with four classes : 
(1) Hydnmeduia, (2) Scaphomedum, (S) Actinozoa, and (4) 
Ctennphora. Also called Cnidaria, Eptthtlaria. 
nematophoran (nem-a-tof'6-ran), a. and n. I. 
a. Same as nematophorous, 2. 
TT, n. A member of the Xemato]>hora; a cni- 
darian or coelenterate naving thread-cells or 
stinging-organs. 
nematophore (nem'a-to-for), n. [< Gr. vy/ia 
(myiar-), a thread, + -VW. < W*" = E. bear 1 .] 
A cup-shaped caecal appendage of the cojnosarc 
of the polypary of plumulanans, sertularians, 
and other hydromedusans, containing numer- 
ous thread-cells or nematocysts at itsextremity. 
nematophorous (nem-a-tof 'o-rus), a. [As nenia- 
tophore + -ous.] 1 . Ot or pertaining to a nema- 
tophore. 2. Pertaining to the Sematophora, or 
having their characters; cnidarian. Alsonemrt- 
tophoran. 
Nematophyceae (nem'a-to-fi'se-e), n.pl. [NL., 
< Gr. vmta (vi/fiaT-), a thread, + ^iof, a seaweed, 
+ -e<e.] An order of multicellular chlorophyl- 
laceous algae, consisting of a single branched or 
unbranched filament of cells, propagating by 
means of oospores or zoo'gonidia. It contains, ac- 
cording to Rabenhorst, the families Ulracetr. Sphariyltetr, 
Canfmacea, (Kdogoniacece, Vlnthrichra, Crovlrpidira, and 
Choctuphorecf. Ijiter algologista have made different dis- 
position of several of these families, placing them In the 
Zoosporece. 
Nematophycus (nem'a-to-fi'kus), n. [NL.. < 
Gr. vfiiM (vtniar-), thread, + ^itor, a seaweed.] 
The name given by Carruthers to a plant first 
found in the Devonian of Gasp6 in Canada, 
by Dawson, and named by him Prototaiitm 
and considered to belong to the Coniferce, al- 
though differing in certain important respects. 
The same plant, to which Dawson later gare the name of 
Xematophyton, was examined by Carruthers and placed 
among the Aljtr, he considering It an anomalous alga Mid 
one which it was not possible to correlate with certainly 
with any known alga. Later (in 1K75) the same plant was 
discovered by Hicks much lower In the geological series, 
namely, In the Denbighshire grits (a rock occupying a 
rather uncertain position, but probably near the limit be- 
tween Upper and Lower Silurian). The specimens from 
this position have been Identified with the Xnnatophuaa 
of Carrnthers (the Prototaxitei of Dawson) by F.theridge. 
who considers It as unquestionably forming a portion of 
a colossal seaweed, whose habits resemble those of the 
North Pacific species of the genus Kenoeyitit and the ar- 
borescent Lemania. 
Nematophyton (nem-a-tof 'i-ton), n. See v 
Nematopoda (nem-a-top'o-dft), n. pi. [NL., < 
Gr.v^fia(vri^aT-), thread. + 7roic(n-o<5-)=E./oo(.] 
De Blainville's name (1825) of the cirripeds, as 
the first class of his Miilcnto^otiria, contrasted 
