th;it till' pli'i-tdiil aiiipliiil cniiie to its fdnii.-itidii tliroutili sub- 

 niorgoncc of :i spiral aiiipliiil or tliat tlio sjiiral aiiipliiil dovel- 

 opoil from till' pli'i'toiil tliroU);li cnicrtjencH'. Ill I'itluT case, 

 tliis type must lie eonsiilereil a ecimmon Jenoiiuiiator of the 

 A|iliasmiilia. 



Do Coniiuk Oi''^-)^ •'»« roi'i'utl.v iilaccd tlie family Bustianii- 

 (lae in approximate relation witli pleetoiils on tlie basis of am- 

 pliidial and male supplementary orj;an eliaiaeters. In this 

 grmip he ]>laees PrixmatDhiimuK. Tiipylii, Tiilobus and Bas- 

 tiania. Gross similarity in esophagi support his view hut the 

 writers cannot accept it. The three former Ki^nfi-i seem best 

 placed in the Knojilina (Tripylidao). Do (^ininck notes varia- 

 tion in Ha.stiuiiiii itart\rili.i from unispire to transverse (cyathi- 

 fornO. The writers may add that in Iliistioiiiii cjilin a sinKle 

 specimen had one unispire and one broken circle ampliid. 

 Bastionia and Oddiilohiimii.i are odd iilectoids in havinfi; 10 

 ceplialic setae, the external circle being partially sulidivided. 

 The oddity goes even further in that the six anterior setae 

 (dd., el., vv.^ are slightly longer than the four posterior (Id. 

 and Iv.). Thus we find the ()-(i-4 symmetry of Plectoids re- 

 mains but the size relationships in the two external .subdivisions 

 are reversed. The genera Bnntinnia and 0<lnnti)laimi(s seem 

 best placed in the family Hastianiidae as an appendix to the 

 Plectoidea. 



A.r(inol(iimoidta. In tlii.s superfaniily one finds the same 

 base symmetry as in the Plectoidea, namely an internal circle 

 of six papillae, a subdivided external circle of six papillae or 

 slKirt setae (dd., el. vv.) and four long setae (Id. and Iv.). In 

 addition paramphidial setae are apt to be found .just posterior 

 to the cephalic setae. Such .setae may be four (two pairs) in 

 number, preamphidial (Sabnticria loni/icaudala) or postamphi- 

 dial (Laimilla quadristiosa) or they may be eight in number 

 (four pairs) {Odontiijdiora anpiistilaiiiia, Axonohiiniiis siib- 

 similis, A. ndi>nlop}ivri)ides). 



The family Comesomatidae is rather uniform in having nuil- 

 tispiral amphids but the Axonolaimidae, are even more diverse 

 than the Plectidae. Aracalnimiis (Arncolaimoidcs) ^osierae 

 Axonolaimii.s siibximilis and Odontophora have rather distinct 

 double contour unispire ani|diids, Arat'olaiiniis ci/liiidrolaimus 

 has a broken circle to single contour ampliid and Ci/liiulro- 

 laimiis commumis a circular ampliid. The amphids .show nu- 

 merous gradations in elongation from the unLspire type in 

 AxonnJaimus subsimiU/< to the inverted U of Axonolalmus spino- 

 sus and shejiherds crook, PscudoIcUa granuUfera. As in the 

 Plectoidea, each external aniphid is a spiral groove, posterior 

 closure of which leaves a central elevation. Argialonlaimiis elc- 

 gans represents the sole instance of multispire amphids in the 

 Axonolaimidae. However, the Diplopeltinac introduce still 

 another variant, the presence of lateral shields accompan.ving 

 the amphids (Didelta). In this group one may trace a repeti- 

 tion of the unispire — question mark — circular amphid devel- 

 opment. 



^f(>nhl|■'<fcroidca. Monhysteroids have great diversity in ce- 

 phalic symmetry. The most common arrangement 13 an inter- 

 nal circle of six papillae and an undivided external circle of 10 

 or 12 setae. Stekhoven and de Coninck (10.S3) characterized 

 the group as typically hexaradiate. The one unifying charac- 

 teristic is that the amphids are nearly invariably circular. 



The family Linhonioeidae includes some forms such as 

 Ml talinhomonis typicus and Dcsmolaimiis ^relandicus with a 

 subdivided external circle of six jiapillae and four setae (Id. 

 and Iv.") or (> (5-4 symmetry; others such as Piiniliiihomocns 

 Irptunis, i[(inh}jstrriiim traiisitans and JIalhicma xpinosiim with 

 an undivided external circle of six short and four long setae 

 or 6(6-4) symnietr.v; and still others such as Linhomoeus 

 eUnigatus with an undivided external circle of four short and 

 six long setae or 6- (4-6) symmetry. There usually are, in 

 addition, eight paramphidial setae. The genus Spliaerolaimns 

 presents an arra.v of setae that has not as yet been satisfac- 



torily interpreted. One linds the normal internal circle of 

 six papillae followed by a circle of six short setae (f dd., el. 

 and vv. ) followed by a circle of Hi setae, in eight jiairs, two 

 pairs sulilateral, two submedi:il; in addition there are two pairs 

 of preaiiiphiilial setae and somatic setae arranged in eight 

 longitudinal rows (submedial and siiblateral). One might, pro- 

 visionally, assume that four papillae of the external circle 

 (Id. and Iv.) have been overlooked and somatic .setae have 

 added to ceiihalic setae. On this basis the symmetry may be 

 characterized as filO (4?-0) + 16 (8-8) + 4 (2-2). 



Members of the Monhysteridae sometimes have but six 

 elongate setae (6-4-6) such as Cylolaimium ohliixiriiiiilalitvi 

 but more coninionly there are 10 or 12 setae in the external 

 circle. IliilmKiiicliiix mnrrampliiilinn and Tlurisliis sitiisiis rep- 

 resent the more typical arraiigenieiit with six pafiillae in the 

 internal circle, six short and six long setae in the external 

 circle. Of the latter circle the longest six are the dorsodorsal, 

 ventroventral and dorsolateral. Duplication of the externolat- 

 eral results in a large dorsolateral and a small ventro- 

 lateral. Such symmetry may be characterized as 6-12 (6-6). 

 Paired sublateral preamphidial setae are also present. Scap- 

 trcUa cincta has a peculiar combination of axonolaimoid and 

 monhysterid symmetry. The presence of 6 short setae in the 

 internal circle and 12 setae in the external circle is characteris- 

 tically monhysterid but the external circle consists of setae in 

 three sizes; four are very long (Id. and Iv.), 6 are moderately 

 long (dd., vv., and dl.) and two are short (vl.). Therefore, 

 the external circle might be characterized (2-6-4). Omicro- 

 ncma liloriiim and Slrint-ria sp. represent types with increased 

 cephalic setae. In the former instance three circles are de- 

 scribed, an internal circle of six setae, an intermediate circle 

 of four sublateral setae and an external circle of 18 setae in 

 six groups of three, an arrangement which may be noted 6-4-18. 

 It seems possible that a restudy of OmicrnniiHa will show it 

 to be a sphaerolaim. Stfineria, on the other hand, is typically 

 monhysterid in character having an internal circle of six 

 papillae and an external circle of 10 or 12 setae (according 

 to the species). In addition to the cephalic setae, nnnierous 

 somatic setae are grouped anteriorly in eight longitudinal 

 rows, four submedial and four sublateral. 



Siphunolaimiis has an internal circle of six papillae, an ex- 

 ternal circle of 10 setae of which the four sublaterals (Id. and 

 Iv.) are the largest; this 6-10 (6 + 4) symmetry is more like 

 ParaUnhomoens than any other forms discussed. 



The circular amphid with central fleck is often mentioned 

 as a characteristic of linhonioeids but the central fleck is 

 neither confined to that group nor obvious in all members. 

 As in plectoids, a central elevation represents the inner side 

 of the amphidial groove, be it circular or spiral. The rela- 

 tive height between grooves determines the gross "presence" 

 or "absence'' of a central fleck. 



Paramphidial setae of some type arc nearly always present 

 in monhysteroids; most commonly these are four in number, 

 sublateral preamphidial in position. In addition to which 

 there may be four sublateral postamphidial or four submedial 

 preamphidial setae. 



Six separate or three more or less lobed lips may be pres- 

 ent in monhysteroids but if so, they are generally reduced, the 

 labial elevation bearing faint longitudinal ridges: which are 

 developments of the cheilorhabdions. 



Chkomadorin.\. Jlenibers of this suborder show all of the 

 diverse .symmetry arrangements (Fig. 61) of cephalic setae 

 and nearly all of the amphidial forms present in monhysterins. 

 True lijis are seldom ajiparent but very highly developed 

 cheilostomatal rugae usually t.ake their place. 



Chromadoroidea. The family Microlaimidae is characterized 

 by unLspire, postlabial amphids, an internal circle of six papil- 

 lae and a subdivided external circle of six papillae or short 

 setae and four long setae, 6-6-4 symmetry. True lips are 



Fig. 5H. 



Cephnlic ref^ions in the rurTiallanoide.-i. T^racuneuloidea and 

 Spiruroidea. A-C — Caniallanidae. D-F — C'ucullanidap ; G-H — 

 Philometridae. I-J — Drarunrtilidae. K-V — Thelaziidae. W-KK 

 (except Z) — .Spiruridae. LL-NN & Z — Aruariidae; OO-PP & 

 UU-VV — Physaloptcridae. QQ-TT — Cnathostomalidac. A — Proc- 

 amallanus fulvvlrticonU ; B — CtimalUinus sweeti: V — CamaUanun 

 iiiicrorrplifiluM : 1) — Omfio hoe/t/jlii; E — Ha/ihniptim sinensis: V — 

 CucuUitnttti friittae: (i — M irrnplfurti vivipura : II — PhiUnitetra ru- 

 bra; I — Drtn'uneutuit nieitinenjiis. male: J — Dra*'uncuhis medinfn- 

 SIM, female: K — Thflnzia caUfornienHix : L — Psfudufilnriu ])prtf7tue : 

 M — OxyHjiirttra mnnsotii ; N — Spirorcrca lupi: O — CyUrospiritra 

 ttuhnrfiimlitt ; P — Ajifarops strtintn/Jinti ; Q — Physncephnluif HfXttla- 

 tun: li — SinintitfMia pnrndoxn ; .S — Leiurin tcplorfphidus ; T — Strep- 

 topfiaruniiH artiiatiiH : V — Riclidnrin roJoradienfiiK : V — Gntttjj/lo- 

 neriia pntrhrnm: W — Spirtira ri/tipUtiritp>i ; X — Protnspirurti ntt- 

 midica ; Y — Rhitbdnrhotui kidderi: Z--~Stf{tophnrtt/t Htelhte-polaris. 

 AA — •Spinitectus cnrolini ; BB — Huhronema microstoma; CC — 



l>rnsrhia metniKtoma : DD — firurociirnrn unrinipfnijt ; EE — Para- 



hronrma inilirlim; FF — Odaiitospirura rrtinpfniji ; GCi Masln- 



phiinis miiriK; HH — Ci/slUlirnla stigmnlun; 11 — Hedniris sp. 

 •IJ — Trlramfres iimericana (male) : KK — Aacnrophis harvoodi. 

 I,L — -Icrinria anllniris; MJf — Tsrria coronula: NN — Sehinto- 

 phorus ciic\illat<iit: 00 — Skriabinoptera phrynoHoum ; PP—Thu- 

 hiniara leiolopismue ; QQ — Kpiroxys rontnrta ; RR — Hnrtertin fjal- 

 liiwnim: S.S — Tnnqun tiara; TT — inri/raranlhus pinnatifidut ; 

 VV — Abbreriala mnrdrna; VV — Physaloptera maxitlarix. A — 

 After Li, in:!.5, .T. Parasit., v. 21(2). B — After Moorthy, 1937, 

 J. Parasit.. v. 2:i(.'!). D-E' — After Hsu, 1933, Parasit.. v. 24(4). 

 L — After Sandgrouiid, 1935, Rev. Zool. Hot. .\fr. v. 27(2). EE — 

 After Bavlia, 1921, Parasit., v. 13(1). FF — After Welir, 1933, 

 Prnc. IT.'S. Nat. Mus., (29.i8) v. 87(17). Z. MM. NN— After 

 Welir. 1934 J. Wash. Arad. Sc. v. 24(8). Remaining fiEures 

 based upon Ohitwood & Wehr, 1934, Ztschr. Parasit. v. 7(3) and 

 iinpuldished observations. 



63 



