Kliinchiliir pi(itiiiil;isiii of tlio siilivoiitiiil scctins seems tii lu' 

 ('(iiitimioiis iiiicl ciiii' (•(iiicluiies tliat in tliis ciise tlie suliventi:il 

 nWiiuis ;irc liiiuu-le:ite ; the ducts freiii nil three kI"!"!*' exteiiil 

 anteiiorl.v into the teeth of tlie stoma wlieie eaeh (ipeiis in a 

 niinnte imre. Kaiither (1!MI7) reeonleil four esophageal n'-i'i'l^ 

 in the siiliventral seetors of Onrlidlaimiix viih/aris. He foiiml 

 separate pores for the liimlmost pair sitnateil somewhat an 

 terior to the nerve riiiR ami ilorsal to the center of their re- 

 spective seetors. 



Kiiri/sliimina oiiiciirdiifi lias a ver.v similar esophagus to 

 Mtiiiiichiildiiniis but its narrow part (corpus) has distinet cu- 

 tieular attachment points anil the musculature is concentered 

 in the corpus ( Kig. !>4T) Imt not in the liulliar region; Ull 

 radial nuclei are i)resent, there heing 1>< in tlu' corpus as in 

 Ml l(inc}i<il<iiiiiiix. liut there are 12 in the glandular (liulhar) 

 region arranged in two sets of six as in TiipjiUi anil Primi- 

 rhiiliix. The esophageal glands extend the entire length of the 

 esophagus as in oncholaims but only tliree gigantic gland 

 nuclei (Fig. !14U) have been observed, the right subventral 

 being much the largest. Onl.v eight luielei have been seen in 

 the esojihago intestinal valve, the anterior part of wliieh is 

 triradiate while the posterior part is dorsoventnill.v flattened. 



Knnjihi.s' romniiini.i has a cylindrical esoph.agus more like that 

 of oncholaims than Eiirjixtiniiiiia but .3.'? r.adial nuclei are prcs 

 ent, the corpus containing the full number of l!4 nuclei as in 

 Tii/ijihi. while the bulbar region (glandular part) contains 

 only nine as in Mi Idiichnhiimiis, the last group of three indi- 

 cating again a ease of suiiiuessed cleavage (Fig. O.T.Ai-.X.A ). 

 'I'here are three large subequal esophageal gland nuclei in the 

 bulbar region and the corresponding glands eaeh has an ori- 

 fice at the anterior end of the esophagus, at the base of the 

 teeth. The short, well developed, triradiate esophago-intestinal 

 valve of Eiiopliis contains ll-l.l nuclei (number questionable). 

 Rauther (1007) obtained the same total as the writer's (i.e., 

 IIHI nuclei which includes nerve cell nuclei and esophago-in- 

 testinal valve nuclei) but he differs in some eases as to the 

 functions he attributes to specific ones. He also describes two 

 lateral glands (the nuclei of which we designate xi_-j in Fig. 

 ;•(! & !).")S ) near the mid region of the esophagus which open an- 

 teriorly near the level of the amphids in the marginal region. 

 We agree that these proliably are esophageal glands but were 

 unable to distinguish their orifices. 



The esophagus of Phanodennopsis Innfjiselae is interesting 

 because it is representative of forms with a crenate glandular 

 esophagus which is commonly termed "cellular." The illu- 

 sion of cells (Fig. 91) is created through the localization of 

 extremely sparse musculature at intervals, separating swollen 

 regions of nearly exclusive glandular tissue. Though the 

 esophagus is conoid and crenate the nuclear distribution is 

 similar to that found in Eiinplii.i with the following e.xceptions: 

 There are ,3(1 radial nuclei, tlie most posterior group being sub- 

 divided into two .sets of three nuclei; the two chief suliventral 

 gland nuclei are much enlarged as are the glands, while the 

 dorsal gland nucleus is situated far forward and much reduced 

 in size, and the small subsidiarj- (lateral glands of Rauther) 

 subventral gland nuclei are situated near the dorsal gland 

 nucleus (Fig. E14FF). The chief subventral glands (Fig. 

 94GG) empty into the stoma while the dorsal and subsidiary 

 glands appear to have their orifices posterior to the nerve ring. 



Leptnsomatiim eJongaliim, representative of still another 

 t.vpe, has multinucleate subventral esophageal glands. The 

 conoid esophagus is of smooth contour, somewhat vesiculate 

 internally. The anterior part (corpus) contains the same 

 nuclei found in PJiaiioihrinopsis while the posterior jiart con- 

 tains such a large number of nuclei (about -.3 in each chief 

 subventral gland) that it would be difficult to designate the 

 types accurately. The dorsal gland is uninucleate, the nucleus 

 (Fig. 94X) much larger than other nuclei of the esophagus: 

 the subventral gland orifices are at the anterior end of the 

 esophagus while the dorsal gland orifice is somewhat further 



(M-X — Corpus: 0-P — bulbar region: Q — e.sopJuigo-intestiii.il valve: 

 K — longitudinal sagittal through regions shown in <)-Q dorsal to 

 reader's right). S-U — EuriiHtominn americana (S — anterior part of 

 corpus: T — posterior part of corpus; TT — glandular region). V — .I71/1- 

 rnma litnris. Near anterior end of esophagus, subventral gland orifice 

 and suttdorsal (dorsolateral) ducts. \V-X — Lepto/foriui/nw rlonuatuin 

 V. acephfdatitiii. (AV — Region of ocelli. ~t ducts also visible: X — glandu- 

 lar region). V-DD — CrupfonrhuH nudua, (Y — posterior end of glandu- 

 lar region; I>D — corpus). Z-('(" — Ironti/t ipnfivJtH (Z-head; AA — dor- 

 sal gland orifice; (stomatal region); BB — beginning of corpus or 

 end of stoniatal region: CC — posterior j)art of glandular region (corpus 

 proper is like fig. I>r>). EE-OG — Phaiioilfrinopxijt loniiiKfUir. (Ep] — 

 Posterior part of corpus; FF — anterior part of glandular region; 



GG posterior jiart of glandular region). HH-II — Dorpldii.iujt nbtiisi- 



caudata. (IIII — (.'orpus at level of stylet cell: II — glandular region at 

 level of dorsal gland nucleus). .T.T-KK — Tn'phnwhiutH sp. f Glandular 

 region sliowing five esophageal gland nuclei,) 



posterior. In the corpus the musculature is concentered (Fig. 

 94\V) and the esopli;ige:il lining thick but without attachment 

 points. According to .lagerskiidd (1901), Turk (1903) and 

 Rauther (1907) the esopluigi of the related genera Thoracas 

 loma and ('i/lirdldimiia (which ;ire grossly cylindrical) have 

 similar esophagi except Unit the esophageal lining has defi 

 nite cuticular attachment points. Rauther was able to dis- 

 tinguish small subsidiary subventral (lateral) glands as in 

 Kniipliis. Other enoplids, such as Anlinima (Fig. 94V) and 

 Iili(ib(l(i(l( mania, with cylindrical esoiihagi have gland orifices 

 in similar positions to tho.se jibove described, with a simple 

 i.e., enoploiil esojdiageal lining. 



In tlie wliole order Knoplida jiigment spots or ocelli occur 

 only in the superfamily l']noidoide;i, families Knoi)lidae and 

 Oncholjiimidae, and are of s]ior;idic ;ippearance in these groujis. 

 In the Onchiihiimimie such |iigment is rather diffuse in the 

 musculature of the corjms while in Etiiipliix it is concentrated 

 in ;i pair of subdorsal spots in the m;irgin:il ;ireas near the 

 anterior end. Well developed "ocelli" li:ive been described 

 in l>eptosiimatids, phanodermatids and enchelidiids. 



I'inally we come to the f:imily Ironidae which in many ways 

 :ipi)ears to have closer affinities with the Mononchidae and 

 Dorylaimidae than with other enoploids. Ironitx (Fig. 94Z-CC) 

 and IrnncUa liave cylindrical esophagi with well developed 

 cuticular attachment points, concentered radial muscles, and 

 ." subequal esojihageal glands. TJke Enoplux, nnchnlaimnx, 

 and Tripi/la. three of the glands have orifices into the stomatal 

 region. I'ri/pt (inch 11.1 niiihi.s; though otherwise very similar to 

 Irnviis, h:is its esophageal glands confined to the posterior part 

 of the esojihagus (Fig. 941)1) & V). Tt seems, therefore, to be 

 intermediate between such forms as Prioncliiiliis and Irnniis. 



t)ORVi,.\rMiNA. — This suborder is jierhajis more couii)act 

 in fundamental esophageal organization than the suborder 

 Enoplina though the gro.ss morjihology is certainly more di- 

 verse and includes more odd types (Fig. 91). Dorylaimins 

 have one point in common with each other and with the family 

 Mononchidae, namely that none of the esophageal glands ex- 

 tend to the stomat,al region. The suborder contains superfami- 

 lies with esophagi of two types, one in which the glandular 

 region is tremendously elongated, the subventral glands re- 

 duplicated and ])rotruding from the esophageal contour, and 

 the other in which the glandular region is either short or only 

 moderately elongated, and in which only two pairs of subven- 

 tral glands are present. This latter group includes the soil 

 and aquatic species of the superfamily Doryiaimoidea while 

 the former group includes the parasitic nemas of the super- 

 families Mermitlioidea and Trichuroidea. 



Dorylaimoids have a cylindrical corpus followed by eitlier 

 an elongated cylindrical glandular region (Dorylaimidae) or a 

 short P3'riform glandular region (Diphtherophoridae, Lep- 

 tonchidae) the parts sometimes separated in the latter instance 

 by a more or less distinct isthmus; the esophageal lumen is 

 subtriangular anteriorly, rapidly becoming minute and tri- 

 radiate with marked cuticular thickenings of the esophageal 

 lining (Fig. 94HH); the musculature is strongly concentered. 

 The radial musculature is well developed throughout the 

 esophagus in leptonchids and dorylaimids but r;itlier degen- 

 erate in the glandular region of diphtherophorids. 



Donjiaimiis i)btii.tiraii)hitiix has an esophagus extremely simi- 

 lar to that found in Pii<i))cliiiliiii for the anterior part (corpus) 

 contains four sets of six radial nuclei (three sets in the nar- 

 row part, one at the junction of the anterior and posterior 

 parts) and only one set of three marginals (Fig. 90) ; the 

 posterior glandular (bulbar) region contains two sets of six 

 radial and two sets of three marginal nuclei, the hindmost 

 set of radi.'ils being somewhat subdivided but arranged in a 

 manner indic;iting they act as a unit. Each of the five esopha- 

 geal glands has its orifice near the level of the nucleus with a 

 very short duet. The dor.sal gland bifurcates, each branch 

 continuing to divide dichotcunously and the branches enter the 

 subventr;il seetors, eventu;illy coming to fill the entire non- 

 muscuhir part of the esophagus ;interior to the subventral 

 glands (Fig. 94II). These latter are found in two pairs 

 considerably jiosterior to the dorsal gland; the first subventral 

 gland on the right .side is considerabl.v smaller than the others. 

 The esophago-intestinal valve of dorvlainiids is very well de- 

 veloped, elongate, dorsoventrally tlatteued, :ind contains 27 

 nuclei. 



There is in addition to the usual number of nuclei of the 

 esophagus a large nucleus in the left subventral sector which, 

 with its surrounding protophism, acts as ;i generative nucleus 

 of the stylet (Fig. 941111). .\s previously st;iteil the stylet is 

 formed in the procorpus and moves .-interiorly to take its final 

 position ;itt;iched to the anterior end of the esophageal lining. 



LrplnnrJiHs has an esnph:igus apparentl\' identical internall.v 



i»l 



