HOOKWORMS OF THE GENUS UNCINARIA OF THE DOG,FOX, AND BADGER.
B. H. Ransom,Assistant Custodian, Helmintliological Collections, United States NationalMuseum.
Looss in 1911 described, as a new species which he named Uncimina
'polaris, a hookworm from Vulpes lagopus, North America. Inthe same paper he redescribed Unchuirm cinniformis originally re-ported by Goeze in 1782 from the European badger {Meles taxiis).Furthermore, he concluded that Uncinana stenocephala (Railliet)whose type host is the dog in Europe is identical with U. a^inifarmts.The specimens (at least 12 in number) from which U. polans wasdescribed were sent to Looss by Stiles many years previously (Looss,1911 p 194). The original material, Looss states (p. 213), bore thenumber 3250 and came from the Zoological Gardens, WashingtonD C The number 3250 evidently refers to a catalogue number ofthe Helminthological Collection of the United States NationalMuseum, inasmuch as there are in these collections at the presenttime, labeled with this number, numerous specimens of hookwormswhich according to the label were collected from Vulpes Ugopus atWashington, D. C, by Hassall, August, 1901. These specimens sofar as I have examined them are all of one species and correspondclosely to Looss's description of UneiomrM polaris. UndoubtedlyLooss's specimens came from this lot of material and unquestionablythe specimens now in the Museum Collections under the cataloguenumber 3250 belong to Looss's species, Uiicinaria polaris.It does not appear in Looss's paper whether he actually examinedspecimens of Uncinaria fi^om dogs before arriving at the conclusionthat Uncina.ria stenocephala is identical with U. cnmfoimis. Al-though he states in general terms that " VixcimiTia cHniformis iscommon in canine animals in various parts of Europe " (p. 194) andthat it occure " in various Canidae and Mustelidae of mid and north-em Europe " (p. 213) , he does not say specifically that he has studiedspecimens from dogs. On the other hand he refers definitely to Urv-cinaria crinifonnis from Meles twx.m (p. 607) in connection with hisdrawings (figs. 105 and 106a) of the mouth-capsule of this species.No. 2533?PROCEEDINGS U. S. NATIONAL MUSEUM. VOL. 65. ART. 20.
2 PROCEEDINGS OF THE NATIONAL MUSEUM, vol. 65.In any case, irrespective of the possibility of the occurrence of thespecies, which Looss calls TJ. criniformis^ in dogs, there is unques-tionably another species common in European dogs, which Railliethas called Uncinm'ia sfenocephala, that is distinctly different from U.criniformis of Meles taxus. Furthermore ZJncinaria stenocephala in-stead of being the same species as U. criniformis is in reality the sameas U. polaris. Not only does Railliet's description of U. stenocephalain certain important respects (size of worms, maximum length ofspicules, and tridigitation of terminal branches of doreal ray ofbui'sa) agree with what is found in the specimens of Uncinaria po-laris (U. S. N. M., 3250) and differing in these respects from what isfound in U. criniformis^ but specimens of Uncinaria from dogs invarious parts of Europe corresponding to Railliet's description ofUncinaria stenocephala agree among themselves and with U. polarisand differ from U. crinifonnis as described by Looss and as shownby several lots of specimens from Meles taxus. For European speci-mens of U. stenocephala from dogs and TJ . criniformis from Melestaxus to compare with V . polaris I am indebted to Prof. P. Ciurea^Bucurest, Rumania; Prof. A. Heniy, Alfort, France; Prof. J. E. W.Ihle, Utrecht, Holland, and Prof. T. Pintner, Vienna, Austria.Readily recognizable differences between the two species involved,Uncinaria criniformis and U. stenocephala.^ including its synonym, Z7.polaris, are shown in the following brief descriptions. The descrip-tions are not intended to be complete but refer specially to charactersthat seem useful for diagnostic purposes.UNCINARIA CRINIFORMIS (Goeze. 1782).Specific diagnosis.?Uncinaria: Male about 5.5 (5.3 to 5.9) mm.,female about 7.5 (6.8 to 8.2) mm. long. The ventral wall of themouth capsule when viewed in optical section from the side is onlyslightly curved as a rule (fig. 9). The boundary line between thethicker ventral portion and the thinner dorsal portion of the mouthcapsule wall (side view) turns forward along the ventral side of thecord of tissue which terminates in the lateral cephalic papilla, andmeets the anterior border of the mouth capsule almost at right angles(fig. 9, x). Esophagus of male about 0.55 mm. long, of female about0.6 mm. long. Lateral lobes of male bursa only a little more thansemicircular in shape. Medio-lateral ray slightly thicker than thepostero-lateral ray and much thicker than the externo-lateral ray(fig. 10). Dorsal ray bifurcated distally, each branch bidigitate(fig. 11). Spicules 0.46 to 0.63 mm. long with rounded membranoustips. Tail of female 125 to 135 [x long; tip of tail into which thecaudal bristle is inserted almost ogival in outline (fig. 12). Vulva4.5 to 5.5 mm. from anterior end of body.
ART. 20. HOOKWORMS OF THE GENUS UNCINARIA RANSOM. 3Parasitic in intestine of Meles taxus in Europe. Not certainlyknown as yet to occur in other animals.UNCINARIA STENOCEPHALA (Railliet, 1884).Synonym.?Uncinana polaris Looss, 1911.SpecifiG diagnosis.? {]ncm2iV\&: Male about 7 (5.6 to 8.5) mm.,female about 10 (7.7 to 12) mm. long. The ventral wall of themouth capsule when viewed in optical section from the side is con-siderably curved as a rule (figs. 1, 5). The boundary line betweenthe thicker ventral portion and the thinner dorsal portion of themouth capsule wall (side view) anteriorly continues to curve towardthe dorsum and meets the anterior border of the mouth capsuleobliquely after crossing the cord of tissue which terminates in thelateral cephalic papilla (figs. 1, 5, x). Esophagus of male about0.75 mm., of female about 0.85 mm. long. Lateral lobes of malebursa rather long, considerably more semi-oval than semicircular inshape. Medio-lateral ray of about the same width as the externo-lateral ray and the postero-lateral ray (figs. % 6). Dorsal ray bifur-cated distally, each branch tridigitate (figs. 3, 7). Spicules 0.64 to0.76 mm. long with sharply pointed tips. Tail of female 150 to 2-90 along; tip of tail, into which the caudal bristle is inserted, bluntlyrounded (figs. 4, 8). Vulva 5 to 7.5 mm. from anterior end of body.Parasitic in the intestine of the dog in Europe (type host and typelocality). Common in fur foxes in Northern North America. Hasalso been found in the dog in Alaska (Hadwen) and in the hog (instomach) at Ottawa, Canada (Hadwen).REMARKS.A lateral view of the head is usually more readily secured inmounted specimens of U. crinifonnis and U. sfenocephala and in myexperience is more useful for diagnostic purposes than a dorsal view.Dorsal views give very variable pictures because of differences in thetilting of the head in different specimens, and comparisons of speci-mens and of drawings are more difficult than in the case of lateralviews. It may be noted as of interest that Railliet's drawing of thedorsal view of the head of Un^inaria sfenocephala (see Railliet,1893a fig. 331) corresponds vei-y well with the appearance frequentlyshown by specimens of U. polaris (U. S. N. M., 3250) which happento be less tilted than in the view pictured by Looss (1911, fig. 108).Looss (1911, p. 213) states that the boundary line between thethicker ventral portion and the thinner dorsal portion of the mouth-capsule wall of U. polaris is nearly straight and he shows it but veryslightly curved in his drawing (Looss, 1911, fig. 107). In full lateralviews of the mouth-capsule of U. polaris {= U. stetwceph^la) fromthe fox (fig. 1, a?), and of U. stenocephala from the dog (fig. 5, x) Ihave found it more curved than Looss has described and figured it
4 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. C5.In Looss's drawing (Looss, 1911, fig. 116) of the bursa of JJ . crlni-jormis the postero-lateral ray is shown as thicker than the medio-lateral ray. In all the specimens I have examined the reverse is true(fig. 10).The lateral membranous ala of the spicule is more strongly de-veloped in U. criniformis than in U. stenocephala and extendsaround the tip. In U. stenocephala it narrows down and disappearsbefore the tip of the spicule is reached.In the specimens that I have examined, the cuticle of Uncinarlastenocephala is usually considerably thicker than that of U. crini-formis. For example, on the tail of the female of the latter speciesit has not been found to exceed 5 [a in thickness, but commonlymeasures 7 or 8 [jl in thickness in the same region of the female ofU. stenocephala.In both U. a^niformis and U. stenocephala the excretory pore,nerve ring and cervical papillae are located in the same generalregion of the neck, but vary more or less in their relative positions indifferent specimens in both species. I have failed to find constantdifferences in these characters between the two species.The caudal pores on the tail of the female are about 45 [x from thetip (excluding the caudal bristle) in U. stenocephala, and in theonly case measured in U. cinnifo^'mis were 30 [i from the tip.It is of interest to note that as yet Uncinaria stcTwcephala is notknown to have become established as a parasite of the dog in theUnited States except in Alaska. On the other hand it is a commonparasite of the foxes on fur farms in the Northern United States,including Alaska and in Canada, and is one of the most serious pestswith which fox raisers have to contend. Thus far, the only casesof this parasite in dogs in North America of which I have knowledgeare those seen by Hadwen in Alaska. The same observer has foundU. stenocephala in a hog at Ottawa, Canada (Ransom, 1921, p. 190).ADDENDUM.While the present paper was in the hands of tlie printer twopapers, one by Fiilleborn (1924) and one by Cameron (1924) haveappeared which bear upon the question of the identity' of Unchuiriapolcn'is and U. stenocephala. Both authors are of the opinion thatthe two forms belong to the same species, an opinion which accordswith my own findings based upon a study of the material fromwhich Looss obtained his specimens of U. polaris. Cameron appearsto be doubtful whether the fonn described by Goeze as Ascai^scrinifarnvis should be considered an identifiable species. In viewof the fact, however, that a well-defined species of Uncinaria occursin the European badger which seems in all probability to be thesame as that described by Goeze there appears to be no good reason

U. S. NATIONAL MUSEUM
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PROCEEDINGS, VOL. 65, ART. 20 PL I
i/nc/nof^ia
ART. 20. HOOKWORMS OF THE GENUS UNCINARIA EANSOM. 5
wh}' it should not be accepted as belonging to Goeze's species until itcan be shown to be different.REFERENCES.Cameron, T. W. M.1924.
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Dochmoides: a new genus for the hookworm "Uncinai'ia" stenoce-phala Railliet. Journ. Helminth., London, vol. 2, pp. 4&-50, figs.1-5.FtJLLEBOBN, FrIEDRICH.1924.?Beraei'kungen iiber die Identifikation von " Hakenwiirmern." Arch. f.Schiffs-u. Tropen-Hyg., Leipzig, vol. 28, pp. 12-15, pi. 1, figs. 1-6.Looss, A.1911or.?The anatomy and life history of Agchylostoma duodenale Dub.A monograph. Part. 2. The development in the free state. Rec.School Med., Ministry Education, Egypt, Cairo, vol. 4, pp. 159-613, pis. 11-19, figs. 101-208, photograms 7-41.Railliet, Alcide.1893a?Traite de zoologie medicale et agricole. 2 ed. [faso. 1]. 736 pp.,494 figs. 8?. Paris.Ransom, B. H.1921.?[Unusual parasites of the domestic hog] [Read before Helmintho-logical Society of Washington, Nov. 20, 1920]. Journ. Parasi-tology, Urbana, 111., vol. 7 (4), June, p. 190.1922.?[Notes on hookworms] [Read before Helminthological Society ofWashington, May 14, 1921]. Journ. Parasitology, Urbana, 111.,vol. 8 (2), Dec, 1921, p. 96.EXPLANATION OF PLATE.All figures drawn witli camera lucida at same magnification as indicated byscale on plate. ABBREVIATIONS.e. I., externo-lateral ray.
I. p., lateral cephalic papilla.m. I., medio-lateral ray.p. I., postero-lateral ray.T., boundary line between thicker ventral portion and thinner dorsal portionof lateral wall of oral capsule.Figs. 1-4.
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Uncinaria polaris {=stenocephaIa)
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FiG. 1.?Head from left side. U.S.N.M. Helm. Coll. 3250.2.?Male bursa from left side. U.S.N.M. Helm. Coll. 3250.3.?Dorsal ray of male bursa. U.S.N.M. Helm. Coll. 3250.4.?Tail of female from left side. U.S.N.M. Helm. Coll. 3250.Figs. 5-8.
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Uncinaria stenocephala.Fig. 5.?Head from left side. U.S.N.M. Helm. Coll. 19,326.6.?Male bursa from left side. U.S.N.M. Helm. Coll. 19,326.7.?Dorsal ray of male bursa. U.S.N.M. Helm. Coll. 19,330.8.?Tail of female from left side. U.S.N.M. Helm. Coll. 19,380.Figs. &-12.
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Uncinaria criniformis.Fig. 9.?Head from left side. U.S.N.M. Helm. Coll. 3392.10.?Male bursa from left side. U. S.M.N. Helm. Coll. 24,788.11.?Dorsal ray of male bursa. U.S.N.M. Helm. Coll. 19,332.12.?Tail of female from left side. U.S.N.M. Helm. Coll. 3392.