LINKINS ‘A Stody of Acanthocephala from Fish of Lake Michigan | o — Loolegy A. OM, 1914 UNIV OP TLINOLS LIBRARN ie: a 4, 4 t 1. * A ae 8 ; net > fet Z _ r & ILLINOIS OF LIBRARY PRBS. A : Sh i, Shes § * te Nite : => Mood %, mr ‘ - 4 . , f = oF ~. i as = we te Ee a A XS * e ate ** ong ae A§STUDY OF ACANTHOCEPHALA FROM FISH OF LAKE MICHIGAN RALPH HARLAN LINKINS A. B. Illinois College, IQII THESIS Submitted in Partial Fulfillment of the Requirements for the Degree of MASTER OF ARTS IN ZOOLOGY THE GRADUATE SCHOOL OF THE UNIVERSITY OF ILLINOIS ». 1914 f my La kal a Bes | £ Wahl ie Pe a | ik eh Lae WA REDO fan i p ¢ ? ond “~ oe iL i> ; , TH ean a WF » 7A *) P “ ‘ y, tt oa ot FT ' J ; ; . hs eres R “@ Hirt) ey De sue ae <3) fg oh 3 mes ’ bis Alvi 5 j et a x LAR qh" 4." = ce D 14 bi UNIVERSITY OF ILLINOIS THE GRADUATE SCHOOL | June 6, 1904. ] HEREBY RECOMMEND THAT THE THESIS PREPARED UNDER MY SUPERVISION BY R. H. LINKINS ENTITLED ........... A STUDY OF ACANTHOCEPHALA FROM FISH OF LAKE MICHIGAN meeeacCEPTED AS FULFILLING THIS PART OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF ARTS \ z Recommendation concurred in: Committee NN Ne ecco cassie oohicnkncWunsianecncarca cannon Reeeaste acts ronan hon re , ; on Ss Final Examination 7 ~ = ee ts be i a ‘oe vennahti ms sist tudyotacanthoce Olin = te oe aie a A STUDY OF ACANTHOCEPHALA FROM FISH OF LAKE MICHIGAN Introduction - = a. Source of material b. Review of work done on the group in North America c. Technique d. Method of recording hooks II Systematic Analysis - ~ ~ - - - a. Key to genera of Acanthocephala from Fish b. Characteristics which determine species ec. Description of species 1). Echinorhynchus coregoni 8). Echinorhynchus salvelini . Systematic relationships of species 1). Echinorhynchus coregoni 2). Echinorhynchus salvelini III Morphology = a = = = @. Echinorhynchus coregoni 1). Size and general appearance 2). Body wall 3). Proboscis and associated structures 4). Leminisci 5). Reproductive organs a). Male organs b). Female organs and embryos b. Echinorhynchus salvelini 1). Size and general appearance fa 5 4 tae Ain 20 coi ces i J J ~ PE STCy. TCH eo) oe pak Mee eS ae ‘ De Xs ie 7 an Sesiag? va 7 See Sey Arey ke ae eee 2). Body wall 3). Proboscis and associated structures 4). Lemnisci 5). Reproductive organs a). Male organs b). Female organs and embryos IV Plates and descriptions of plates - ~ . ~ 35 V Acknowledgments - ss = * = = is 37 VI Literature Cited - - - - - - - 358 ee ly he a agin Pp eI LG fn HN ln ‘ iP es, Thaw ee Be ‘ a ‘J 7 An F < UI y : : a : Ly P Tukey Fy fa FOG ka Ee saemeeneik ‘ae ha wk oe fontstaed |, (duis, Naa gay oa evi sou OLGGH ‘ eat ; @ a ; . ; Tf _ q e ii 0 8. fe ote i ; ib ‘ 4 | f aS “ ai wy 4 S } “ j | ; J 1t% mes o Lwomta Hesin erus are I INTRODUCTION The present paper presents the results of a study made on the morphology of some of the Acanthocephala from fish of Lake Michigan, with the view of classifying them properly and of making additions to the knowledge of the morphology of the group. The material was col- tected by Dr. H. B. Ward, at Charlevoix, Michigan, in the summer of 1894. Most of the work on this group of parasites has been done on forms found in Europe and until rather recent years practically no work at all has been carried out on this group in the United States. Joseph Leidy was the pioneer worker on the group of Acanthocephala in North America. His first work on these forms (Leidy, 1850) is de- voted, in part, to a description of three new species of Echinorhyn- Chus from various hosts. From 1850 to 1890 he published various other brief accounts in which he described four additional new spec- ies, listing all of them in the genus Echinorhynchus. Of the seven Species originally described by him, four have remained valid; later} he recognized that the remaining three species were identical with | previously described forms. E. emydis Leidy (1851) was transferred by H. J. Van Cleave (1911) to the genus Eorhynchus as Eo. emydis | (Leidy). Edwin Linton was the next to make a report on the Acanthocephala (of the United States; his first account was published in 1888. His Studies have been confined almost entirely to forms found in marine fish of the Woods Hole region. However, he has reported (1893) a jnumber of Acanthocephala from fish of Yellowstone Park. Linton's last work on this group appeared in a paper (1907) in which he de- May et ate) os i me rw he . , “* - iter x ‘ , rts d yer 'y ¥ = 4 ihe a : 4 fa) +: e3 vi 2 potty Fete “Pe rae Troonexrg7 a act i « ‘ at ‘ip ae ‘lad ooeodd ack ereate sae 26 ¥ tiild PRL Ye SeeaSS uae 3 " , Ee eae hs 2 24650 S28°RR cs f “~~ h be 4 = ce) = as te be oy ab As PAT tel are shee) teal tfoug iy oa a -r | & ove ; fiw AB tf Pu « ye , ris . 2s : . iT la «+ * « aa de . ot Ja ert aed a Borris * noe sof Us 2aw joo Certs Tae eee eee Leasing io} eas ot Clet sagas! foqmes bark Sag ees oY if : ‘ ‘ 1 { - ae Wid PO OgoT 1G? Cab VCO WOR | CR i nro mee j wie, Lin \ f a : ‘ re oy nelel 3b 08 ae ‘ > ae Pea] \ / > oo c wie eo. var a ip , Rives the parasites of Bermuda fishes. It is important to note that Linton recognized only one genus, Echinorhynchus, in the group Acanthocephala. Briefly summed up, his contribution to the knowl- edge of the Acanthocephala consists of original descriptions of seven species of Echinorhynchus and one variety of a previously described species from the same genus. Of these seven new species, six remain as distinct species; E. serrani, which was described from a single immature female, has been included by Porta (1905) in E. aurantiacus HRisso (1826). It seems doubtful, however, that E. eeaste Linton (1907) and E. rectus Linton (18923) constitute valid species, for E. medius was described from a fragment of one specimen and E. rectus fiwas described from only two individuals. H. W. Grayoill published (1902) an article in which he redescrib ed E. thecutus Linton (1888); gave a detailed account of the morph- Ology of this form, dealing especially with nuclear structures in the subcuticula and lemnisci; and discussed his experiments. by means of which he attempted to determine the function of the lemnisci. These Echinorhynchi on which Graybill worked came from the intestine of the black bass. In addition to the above, A. E. Verrill (1871), W. S. Marshall and N. ©. Gilbert (1905), and H. B. Ward (1911) have mentioned the occurrence of Acanthocephala in various hosts in the United States. RE in most cases no description of the species accompanied the record. This is the extent of the work done in the United States on this group up to the year 1913 when H. J. Van Cleave (1913) published the Systematic part of an extensive work on the Acanthocephala of fresh iwater fauna. In this paper he described four new species of the jgenus Horhynchus and redescribed one of Leidy's species which he in- BN thE 345 Gm 1a s ae ‘ p< 'm) J ey ays OL 2 « ’ id GA ' a ; h vi aw) * mids bodieeuals f 4 Ms 5 “ ay hg vay | ¥ § Le Fr CRS eee '; ‘ <7 i i oe aie j ee eee ry A ' : a a ye Py rug =] The fact that in a single genus containing five species from hosts in this country, four of which were previous- ly unknown, indicates the little consideration which has been given to this group in the United States. For the past two years the writer has been making a study of the| Acanthocephala from fish, considering especially those contained in Dr. Ward's collection from Charlevoix, Michigan. In this study toto mounts, transverse and sagittal sections stained in Ehrlich's acid iiesery lin, were found most useful in determining the morphological and histological structures. The technique of these forms is very difficult to perfect, for the body is covered with a dense cuticula which offers great resistance to the penetration of reagents. An- other difficulty comes from the fact that in sectioning, the hard- emi embryo often tear the more delicate internal structures. The details of the technique were carried out in the usual manner. The .. were taken down through three grades of alcohol from 85%, in which they were preserved, into distilled water. After washing ifor 5 to 3/4 of an hour, they were stained for one hour in dilute Ehrlich's acid haematoxylin. The specimens were then washed for + hour in distilled water. Those which were to be sectioned were "blued" by washing in tap-water for 15 minutes; and then were car- Beet up through the alcohols, cleared in xylol and embedded in paraf- fin at 52°C. Ten-micra sections were then mounted in series. The individuals intended for toto mounts were taken from distilled water up to 70% alcohol where they were destained by the addition of a few i of acidified 70% alcohol (100 parts 70% alcohol & 5 parts HCl Sup.) . When properly destained, the acid was washed out with 70% jalcohol and the specimens "blued" by adding a few drops of ammonium Spy ial, ¢fé 2 ey : f =e + » rte Ty) bh Zz h ‘ rs ie rate | ey 2 t on gy : a - ¢ ‘ots ‘sio2cee atten landed dels ny - a pers oe . =e a. ~y ”* ; + one as HORS oud 4607 te £rU) wet? Kuinenth a | 4 7 ‘ sa J < AT’ a 3 i 4 ‘) q be ¢ 4 \ > Pr ao a eed 4 — & ttn au b~ Bs 20234) POLS & L£U 38 § FHS Bun wen wave Kt) wow o- 20k -.8OS 116g Giese ’ ; : a y hp? ng” ‘devzedee aff @? gonedeiieg Geeta ee * - ie ~Reliri eee 3. jadtd Von? eft eet Serer ry ©. pieetly iG ohe set aesto- ome a Bo 472, g [ git> BO OLGEe SSR, Oe Cae tele 4 “of ; . Ee ip ‘hi ty be i? * v yr 7OL ¥s apo dy 4 v € “ 4 v ae | ans ae! ag a= 4 fa IASI SOS RS ee See we : 4 (UCR 4 ‘ cela, ee bara , ‘ ‘ e ” ni Lat al zs we m . ‘ . 7" . * r whe ol | See y AE AT . a hw al ake [ts nit pee | 4S pate wate 4 D he ejupe i lolyx #1 Dereelo Rae ieee | ee 1a 2 ; ee WOO Coe ALS oe her a Hic baa et iv oe Oe hls: gst geved one O Romine he wad Wibgecat e Del hed t 95 Ss on rs — dane POEA fodee £3 a , Me tag. COOL , Ledeoka,§ iomnea Yi a c tiv suo Bedsael 2a ods Smerne agaed ie gt = ; ; : ; io sia aioe LD. iy ; 4 ® to wath 4oyhl nes penta ne ae ihydroxide,or sodium carbonate solution, to the alcohol. After wash- ing out the alkali the individuals were taken up through absolute al-} Cohol, cleared in carbdol xylol or synthetic oil of wintergreen and then gradually taken into the balsam. The records of different workers on the group of Acanthocephala are in some confusion due to the lack of uniformity in the method of recording the number and arrangement of the hooks on the proboscis. much lack of uniformity occurs even in records of the individual writers. Porta and von Linstow describe the proboscis hooks as ar- ranged in circular rows at right angles to the long axis of the pro- boscis and record the number of circles with the number of hooks in }} each. The difficulty in this system lies in the fact that at the an, terior and at the posterior ends of the proboscis the circles are often incomplete. Luhe and de Marval in most cases describe the hooks of the pro- bescis as arranged in rows which extend parallel to the long axis of the proboscis. Such rows Luhe calls "Langsreihen" and designates the number of hooks in each of these longitudinal rows. The appli- ication of this method to such probosces as are found in some of the Eorhynchi meets with greatest difficulty, since in these instances there are only a few hooks arranged in three circular rows and if re- corded as longitudinal rows, alternate rows would contain but a singl¢ hook. From this evidence it seems that greater uniformity could be maintained within the entire group of Acanthocephala by strict ad- herence to the system of recording the number of circular rows rather than the number of longitudinal rows. In the following descriptions the writer has adopted the method of Porta and von Linstow. A difficult in applying either system lies in the fact that in » iy oe i! pat: a9 F 6 ie Bs rake eae as sii AD Mit | “ty tf z aor & Casa bate che ae ca oa . I aT. oi mmsate Vo Lo led foetal ats hel AG, gald) Cote) dae am 4 ie i diben STENT OR SHOR RRR Se wba eas i. and & ot Pov bath bo 8 Sd J ASTID UUSSIR SERA ee. ‘ ‘ Sie re of) ‘ ; : , c. a M ; Sov ye’ " - af ene 4 d # py et. ~ . 4 @ iJ *@ Nae Ae; Juve: ona Tso Fee nate Bt | & abeo wotteresd aay faa setale ‘ ‘a BOG egies lf) boced, tenes: Laver ah ol ba ae > A ett 23, 2 (DARK i of, Sopies z w Fh ey hen ae AE ¢ a Cas 7 Mae in 8 3) eens Ps ae , wee + Baal at ag) Seo tosd ii SRCCe Ce so ti. BOAR, Moa Ma Wade Me. ent Oh cee itt bsp’ ‘wi hone Wi / is Geos Lahdgne tars , ‘ian und oe be eth pas tae ao YW LO" Of the internal structures the male genital organs have been found to be specificly constant in their grouping and arrangement. The relation of the testes to each other and the arrangement of the Cement glands are strikingly uniform. In the nine males of E. cor- @goni, n.sp., and E. salvelini which were studied, the writer found ithe grouping of the testes and cement glands to be constant for the species. The writer has found the embryos to vary widely: in E. core- goni, n. sp., from 51 microns to 91 microns in length and from 17 mi- crons to 25 microns in width. In E. salvelini, the embryos measured from 115 to 165 microns in length and from 80 to 85 microns in width. In all cases the measurements were made of mature embryos which had three distinct membranes and were taken from the body of fully mature females and mounted in 85% alcohol. The descriptions of Luhe, von Linstow, Porta, and de Marval show that different species vary as to the degree of constancy in the size of the embryos. In some cases the above authors have given but a single set of measurements, while in other cases, limits of size are given, often showing a rather wide range of variability. Practically all descriptions of embryos are : incomplete,for the stage of development of the embryos measured is not given. Thus in comparing the embryos of unidentified forms with earlier descriptions of embryos, there is no way of being sure that the two sets of embryos are in the same stage of development. c. Description of Species 1. Echinorhynchus coregoni, n.sp.- Body enlarged at anterior end. Males 3.0--3.7 mm. in length. Maximum width 0.8--1.05 mm. at anterior one-fourth of body. Females 3.1--5.4 mm. in length. Wid- est part of body 0.6--1.5 mm. Proboscis cylindrical, carrying 30 Zi : ' on ‘gen fn ‘i xi 42a 4 ~ mae % BG ft 2S TeRIS Fo ee ee sgtoat ' P i ye 8 iv i ot é Phas b re rid Sov lee x tea baas 20 Srp ede we ote ‘og! eae bared med se ‘ cS Gititete feo mont oe G _ ‘ NG BE enorxs im E gre \ Ue . ns rel ml aiotored COL. eae | Mis s} nic? siperes regex baad a, tT: set So Law Bae Se ‘ae Rae ky = « C= ” i 3 ae orf He Pets i a 2 Fase rovacd bE ; FING Y Beko eo tk YOGs i we See Lae Vee i a me % ke ofnel Gate a ‘sth es ma. - ~~ OL9 Pam ow VPEtE ise Pm ‘i = a =) awed ap hey, a? coh ote : . 2 x ee Na >’ “ £ te 10 Beer gabe gi one ~ — Se 1S). ae ae of bi , oo voi Be ogpadqeaons y Sate Bees. woe ere waned $0" eed ‘< _ < ai) ae! Lxoo@te rea ee Bilin tioctor” i oh’ “<4 : os: — am es Seis es —— ‘1 lcircular rows of hooks, each circle containing 6 hooks. Hooks of ad jacent rows alternate. Basal hooks 0.028--0.053 mm. in length. Hooks in middle region of proboscis 0.065--0.080 mm. in length. Term inal hooks smaller than those of middle rows. Ventral hooks larger and stronger than dorsal hooks. Embryos vary from 0.051 mm. to 0.09] mm. in length and from 0.017 mm. to 0.020 mm. in width. The common size is Owen? & OLOLO mm. &. Echinorhynchus salvelini, n.sp.- Body elongate; slightly jenlarged anteriorly. Males 7.0--9.0 mm. in length. Maximum width 0.86--1.27 mm. in region of proboscis. Females 10.5--17.0 mm. in length. Widest part of body measures 1.19--1.58 mm. Proboscis Cylindrical, armed with 26 circular rows of hooks, each circle con- taining 8 hooks. Hooks of adjacent rows alternate. Basal hooks 0.039--0.050 mm. in length. Hooks in middle and anterior regions of proboscis 0.044--0.068 mm. in length. Hooks in middle and anterior region with basal processes measuring 0.083 mm. Embryos vary in length from 0.115 mm. to 0.165 mm. and from 0.060 mm. to 0.065 mm. in] width. Common size 0.140--6.622mm. d. Systematic Relationships of Species 1. EChinorhynchus coregoni, n.sp.- In determining the species of E. coregoni, the writer has taken for a basis Porta's paper (1905), which lists and describes the species of Echinorhynchi parasitic in fish. The writer has compared E. coregoni not only with those de- scribed in the above paper, but also with those described by Luhe (1911), in various papers by von Linstow (1895, 1896, 1906, 1908), in de Marvals papers (1905, 1905), in Leidy's works (1850, 1851, 1852, 1887, 1888), and with Linton's described species (1889, 1892, 1893, re, Ge. Hs). eae ak idl »! Loney heuer - rd a . Pi ' & ys a i 92 a 1 » agree Os rs cae i ee + ETE 1 5 ciate ath ane t ochhy ‘i ity We n te # hong ai ay er Os. Pm eee tin, hay by At Nay » Pins utes 12 | aes ‘ In this comparison forms showing extreme differences have been at once eliminated, those which showed even slight likenesses have been carefully compared with E. coregoni with the following re- sults. E. gadi is similar to E. coregoni, n. sp.: (1) in having the hooks arranged in the same number of alternate circles, (2) in pos- sessing embryos within the range of sizes found in E. coregoni, n.sp.¥j, (3) in a very short neck region. re Gittere from 0. coregoni, n.sp.: (1) in the number of hooks in a circle, (2) in body size, (3) in the isize of lemnisci, (4) in the grouping of the male genital organs. In E. gadi the testes are not in close contact, while in E. coregoni, n. }Sp., the testes are contiguous. Again, the cement glands in E. gadi, though of the same number, are arranged in a row posterior to the testes; those in E. coregoni, n. sp., are massed together posteriad to the testes. E. borealis is similar to E. coregoni, n.sp.: (1) in body size, and in possessing a short collar. This species differs radically ifrom E. coregoni, n.sp.: in having embryos nearly twice as longs as those found in the latter, and in having more circles of hooks with more hooks in each circle. HE, Oricola has the same number of circles of hooks with the same | | number of hooks in each circle as are found in E. coregoni, n.sp. lhe size of the hooks and the body length in the two forms are differ fent, the details of which are shown in Table IV. in E. clavula and E. coregoni, n.sp., the testes are similarly placed in the body and are in the same relation to each other. The body size is nearly the same in the two species. The number of cir- Cles of hooks and the number of hooks in each circle vary in the two * . ‘a s ' - = Ve - . < j iP ; 4 ~~ Sle 4 L te « . f * 2 4 } . iT Oe v mR A3et aose Tiode a * He & shi reaeet 16 _ 7 of. wish Lecepicagy ae aR c+). toahe au s¥old int sande hd whl im » SORE? (te Pee Thcltheey paaw o LLL Ae a AE ’ wttou | Tht Cet paie at one aajuite Oe: a i tee gi - errr. & ts ri A SB ‘ me hed oie NAR aity be adeolrel sa 7 P o* <9, SC pees Aebe: ‘ae huge / . Af 40 “i ORY ae wapif a ig By i ba ex@ etn fry MELE OR ote, tt, a tien aa E. Salmonis is similar to E. coregoni, n.sp., in possessing a range in the number of circles of hooks which includes the number of circles found in E. coregoni, n.sp. However, E. Salmonis has one more hook in each circle. The length of the probosces in the two forms is about the same, but the width is much greater in the case of E. Salmonis. The testes in the two are in the same general relation to each other and occupy similar places in the body. The cement glands of these forms are of the same number and similarly grouped. The body size in both cases is approximately the same. The most notable difference is in the size of the embryos; those of E. Sal- jmonis being larger than the largest embryos measured from E. coregoni, n.sp. The lemnisci in E. Salmonis are about twice as long as those in E. coregoni, n.sp. From the above comparisons the writer holds that E. coregoni, n. Sp., does not belong to any of the above forms with which it has been compared. It shows closer affinity to E. Salmonis than to any of the other species, but ever here the differences See weight to warrant considering it a distinct species, for which the writer pro- | jposes the name E. coregoni. A more detailed tabulation of the rela-| tions of this species to other species of Echinorhynchus is given in the following tables. Oe. Lisa s ¥ 1! j ec ! 4 be : - on “a . 8E.¢ = - ' ‘ ¢ u ” L ta " a { a * of uv av Y ‘ « fe é . ov é ~ Oe” Bred rebut vo Ae ee ae to dtgret Ost) (Ones nee tat ries ate ee ' b, et oe er ah Ss a , ‘ J me : ! oe ‘ay ne ee 3 ‘ i JRa tee Pe . ‘ = { 7° pees ‘ ‘on ‘ . oh bad vd 6 4%, “Vaal Al Se OS Lee & - ¥ wig ha ce ma torgo Di’ se'l atta (Ege SOS os a : S PP Et SW. isa Li-GL ;eploiio- R8-OG =< Siete + ine cae a aps 3 FoecE QUOLL Cl = sia. . RS ee Sate. .t Geis ,teenes68 wae Sixaqas .¢ —~ @eeree ae . ~ . ‘ “ . t id ¢ A aden a) ‘4 . iJ ‘ Lnogetem . % saute : ; ‘ i s , ¢ . << . i Be * +a , 4 ‘ &5 £6 ee, eect a - —- . . * é. - eha “sé ta 4lem : : , : | | +, (8. SOROS Lon wy Z iy ba cot #0 =m SORTS i. TABLE III E. coregoni, n.sp., compared with E. borealis Likenesses: Body size: Differences: Hooks: Hook size: E. coregoni, n.sp.--male 3. female E. borealis -- male 4.94 x female 7.11 . coregoni, n.sp.-- 0.1 mm - borealis -- short - coregoni, n.sp.-- 20 circles of hooks, alternate nm 6 hooks in a circle - borealis -- 25 circles of hooks, alternate 10 hooks in a circle BE. coregoni, n.sp.-- 0.028--0.080 mm E. borealis -- 0.043-mm. > a ih ate 17 | TABLE IV E. coregoni, n.sp., compared with E. oricola Likenesses: Hooks: E. coregoni, n.sp.-- 80 circles of hooks, alternate 6 hooks in a circle E. oricola -- 60 circles of hooks, alternate 6 hooks in a circle Differences: Hook size: E. coregoni, n.sp.-- 0.0288--0.080 mm. E. oricola -- 0.085 mm. Body size: E. coregoni, n.sp.-- male 3.0 x 0.8 mm. female 5.4 x 1.84 mm. E. oricola -- 8.75--10.87 x 0.75 mm. Neck: E. coregoni, n.sp.-- 0.1 mm. E. oricola -- none +111.0 °° ia’ ‘ pAcaoo. Je et BeoReteo. zoe « * BUDE T OR SLGRLE 18} TABLE V E. coregoni, n.sp., compared with E. clavula Likenesses: Testes: E. coregoni, n.sp.-- located near center of body; spherical, in close contact E. clavula -- located near center of body; spher- ical, in close contact Body size: E. coregoni, n.sp.-- male 3.0 x 0.8 mm. female 5.4 x 1.24 mm. E. clavula -- male 3.5--4.3 x 1.0 mn. female 7.0 x 1.0 mm, Differences: Hooks: E. coregoni, n.sp.-- 80 circles of hooks, alternate 6 hooks in a circle E. clavula -- 24-26 circles of hooks, alternate 9 hooks in a circle ] | ; 5 uc .) dite Setagot (Qe TEP ReetoO me 4 cues z w ee ~ 4 - i _ we 4 he \ , ; » - ° | a & ~S ‘ 7 wl J v . . Se ; q _ 19 | TABLE VI E. coregoni, n.sp., compared with E. salmonis Likenesses: Hooks: E. coregoni, n.sp.-~ 20 circles of hooks; each row containing 6 hooks; hooks of adjacent rows al-| ternate EK. salmonis -- 18-28 circles of hooks, each circle containing 7 hooks Proboscis: E. coregoni, n.sp.--0.71-1.2 x 0.17-0.26 mm. E. salmonis -- 0.70-1.0 x 0.250-0.37 mm. Testes: E, coregoni, n.sp.--spherical, in close contact; nearer posterior end E. salmonis -- ovoid, in close contact; nearer posterior end Cement glands: E. coregoni, n.sp.-- 6 grouped together E. salmonis -- 6 grouped together Body size: E. coregoni, n.sp.-- female 5.4 x 1.24 mm male 3.0 x 0.8 mm. HE. salmonis -- female 7.0-8.0 x 1.2-1.6 mm male 3.0-4.0 x 1.2-1.6 mm. Differences: Lemnisci: E. coregoni, n.sp.-- 0.587--0.595 mm. E, salmonis -- 1.0 mm. Embryos: E. coregoni, n.sp.-- 0.077 x 0.019 mm. E. salmonis -- 0.095 x 0.025 mm. t s 7 , » ¥ \ e iy ‘ Ait, BUS ORDE TS ’ ‘ | io Gelge e ar A ars asim : AHA EDS De J | One Tah Ay Lee sé i, * ay ‘" 4 3 P va ae ao a ¢ ‘ i i” psx 3 ‘s pve, i ae en foe ok ae ts ph Sad adbeets £6325 sont ee heawtealte weedeat Sevey i Oy eek Taos = bontatngd testa e fhe 0-4 ) adie At eeae , aaron . 24 Bsub-—Cuticular layer which contains many nuclei irregularily arranged throughout the region. These nuclei are uniformly distributed in tlk body wall. They contain distinct nucleoli which vary in number and in size. In some nuclei there is a single nucleolar mass, while in others there are many nucleoli of different sizes and shapes. The sub-cuticula is divided into two zones. The region next to the cuticula is densely granular, quite uniform in thickness, and oc- Cupies about one-third of the entire width of the sub-cuticula. In ithe region next to the body cavity the protoplasm is less dense but ihas fibrillar strands of protoplasm extending transversely across the wall. Next to the subcuticula interiorly, is a single layer of circu-} lar muscle Mikithied tuisasatery next to the body cavity are longi- tudinal muscle hitese anion in cross section show a definite arrange- ment in circular groups. Between these two layers are scattered a few large nuclei. The subcuticula is penetrated by many transverse vessels, the Lacunae, which are irregular in arrangement and frequently anastomose, |These unite to form a right and a left longitudinal canal, both of which extend the entire length of the body. 3. Proboscis and Associated Structures When the proboscis is inverted it is held within a sheath made up of two distinct muscle layers. Extending from the inner wall of the tip of the proboscis to the posterior wall of the sheath are ban 10,5.¢ of muscle fibers which serve to invert the pieiole: xe proboscis retractor muscles, as shown by sagittal sections, continue through the posterior wall of the sheath and form two bands, one of which be- ais. ie) yr eae Bie ee esa Selo sesat ES ’ | 2 eet Gat 2 OA leet ems es teat = katte of onde) Looe aaa & ws ie “ J i Ak t in oo at . the etleap (tate uaa ef thiw wilde sao BEIss -er6 Jaq t ‘tived (hed eae oc 0 eee pS ee : ualcasots Wty ahitesis 1a 8 oo t , ty - 7 CULE —- M oe aor U uv 3 a] - . ‘ % > rir o% ‘ Ae evra z . “QU any: ‘al ~) ‘ie g! P GTERVTOH 4 7 P re * oe m « by £ Ds A bs aie ay. ty ; 7 ‘s | a ; 3 | ie a Mag ' Pea es “dh thts Vous eS Bie siveuoae + ty Fi ‘ ! i. ee tte ae Eled ek: oh hee teaver eae ana ads 3 fot SEbhat. eee ot bie abariaae | Late Re Eatisd boty BAP ge wtemetien’ gas. 7 ‘Te Sie. Previth Ss ova gl mie eben oti han ¢ hee Peis . deans i ez Oe Oise: i | eae, | ere er Sarees ei iil ones) heal “er - = Sn ee ee ea ZZ 25 comes attached to the dorsal surface and the other to the ventral sia, face of the body. The action of this set of muscles and the coller | retractors causes the complete inversion of the introvert. Located | between the proboscis retractors anteriad to the posterior end of the proboscis sheath is the brain. From this two groups of nerve fibers pass through the proboscis sheath and form the two i eech ee of which is attached to the dorsal and the other to the ventral region : of the body wall. The proboscis varies in size from 1.6 by 0.6 mn. to 0.71 by 0.8 mn. Since the proboscis was always inverted, the length had to be determined by combining the length of the extended and of the inverted portions. The proboscis is armed with hooks arranged in 20 alternate cir- cles, each containing 6 hooks. The circles nearer the neck are ofte incomplete. The hooks vary in size and shape. Those close to the neck are much straighter and more delicate than those nearer the tip of the proboscis. On the ventral surface the hooks are strikingly larger and more strongly built than on the dorsal surface. This difference is most clearly seen in the rows of hooks close to the body. The anterior rows of hooks have a definitely differentiated. basal portion which is not found in the posterior hooks. Transyerdel sections show large nuclei at the bases of the hooks. 4. Lemnisci (figs) The lemnisci,are two large organs located at the anterior part of the body. » They are attached to the collar at the point where it joins the proboscis sheath. One lemniscus is dorsal in position, the other is ventrally placed. The lemnisci show much the same structure as is found in the fibrillar part of the subcuticula. Ther¢ > AM wLelevad, €1ev. cae eg oa aN x ‘ y givers epee wre Be +: (ikaw ed! weiss “(a0 i tee ieaeset taba 1 Sst ale Ri. . : + vantant st 2 : 44868 sor pale At a oy, aD A 1S09 haa Cok SSO hae. st ig haha wa ‘ He File oe) vas we'sod. mgd ay ele thbe : aes sd Md hi fe LO. a tov 22 fete x + eile f 2 want Py by Jond oa 4) Tea ; aad wow) St eR Dak eo Bere fptay ake oft) Do eared) eae “toleue optal nog | oe dean ri " noe Wen iy HoRons aiagte ay de othe ee ! f 28 Rel hey Oe o cial ‘ome: Nes Lhe | , ws Ph , ff es Lae ty “eB SRE orgie 2 Shah wanes Baty. ee. Loose ead ges: wet Bah on t Lo eee ‘ Palen sé >, if i Fh aia UAE eT 1 Aimee eR RN TINY I me a - 8 i an NT GE fare large canals extending transversely through the organs, and around these canals are nuclei similar to those in the subcuticula. Those of the lemnisci, however, are much larger. Each lemniscus is surrounded by a delicate membrane which extends beyond the posterior end of the structure and is attached to the body wall. Just what connection, if there is any, exists between the two lemnisci the writer has not been able to work out definitely. A canal can be traced part way around the anterior end of the prohoscis sheath, and evidence indicates that the two lemnisci open into this circular can- al, although such a connection has not been demonstrated. Since there is such a marked resemblance in the canal arrangement and the eeneral structure of the subcuticula and the lemnisci, it seems pos- Sible that there may be some connection between these parts, probably | through the lateral canals of the subcuticula. 5. Reproductive Organs In this form the two sexes are different individuals. The male japparatus consists of several parts. A pair of approximately spher- 1g. 4, ical testes,are arranged one behind the other just posterior to the. \o 3h) proboscis sheath. Posterior to the testes are six cement glands, grouped together. They are ovoid in their general outline, although there is some irregularity in this particular. Behind this the buma figs) begins as an eae cup,from the posterior narrow end of which ex-|] 51. tend the oe Around ies ate is a group of large nerve cells which form a genital ganglion” The final part of the bursu is a much folded tube which has on its walls in the region of the cirrus jiour disc-shaped structures which I interpret as adhesive organs whic aid in copulation. The whole system is swung in a clear sac which ‘? Peak a Se OPA up elites si Mayo Dee + 1a ak Co aga la zy nhl eet ad one Ch tees ‘ede eae ‘sit os if (cd dap el ee osuseeae ae ot) Le > Tint ane ag B SAE SG all ak ac: Soh era ere! Beues Ad vee Py mel Od BAP SORE gatas bi t i < Sate & ares, | i yr, s (Sidue.et Dieta 2 cae ee 7 ne ON topta eee 6 dea f Lene wth, eee | ‘Veadtoyed eae iy gcc seed ea": per rh ef US sy cumete eo probably is a modification of the suspensory ligament. The female genital apparatus is held in the ligamentum suspensor um which is attached at its anterior end to the posterior tip of the proboscis sheath, Posteriorly the ligament is attached to the pos- terior tip of the body wall. The apparatus is divided into two dis- Ginct regions, the uterus and the vagina. The uterus consists of an anterior complicated selective apparatus by means of which only the Spindle-shaped embryos are allowed to pass down the uterus to the posterior region of the structure. From the selective apparatus the uterus extends as a long tube with a single layered wall to a vaginal region which is surrounded by gland cells and sphincter muscles. In | the region of the vagina, the cavity of the uterus increases in size and is abruptly narrowed into the vagina. At this place the wall of the uterus is thickened. In the mature females no ovaries were found, but the body cavity iwas filled with embryos in all stages of development from egg masses ito the fully developed spindle-shaped embryos with their three dis- tinct membranes surrounding the inner granular mass. The egg masses are ovoid, but vary in size. These egg masses with the embryos were; loften found in such numbers as to completely fill the cavity of the female. The embryos were best studied by removing from the female and examining in 85% alcohol. Two methods were used in measuring embryos from two individuals: (1) by making camera lucida drawings of the embryos and then measuring these drawings, and (2) by direct measurement of the embryos with the ocular micrometer. One method acted as a check on the other. By the former method the greatest number of embryos measured from 0.077 mm. to 0.081 mm. in length with @ range of variability from 0.063 to 0.09 mm., and by the same method py | Li | ff TOT pl) Se) ok “a at he oxida ad z9 Pa P A, te a a Teh. ohms Pf et fi ; Pe ‘ ys intnd’ ative | ihaiatie ee aa ee ES. Sab MOV Te 1 | eee ree oct te 0 ; Ty Jal50 8 U To Des irs ok é vi él? antay + : g “ o 3 Pe v Mii ns eo 4 . WE ae t “on matt a o f - -OSL9 is yi vlad % ie Jelaggaos Of ee) ASS desks ai bie my ee vihuse Peed rae sh atcha ari laa nda] « OR Gia pee ‘el sath SU) Quite 4G NL) i gbeublwebad ow’ acne th pevd?: po byaiee pai? Sad aa yicia vy yy 4 wa oN “Oe fs | Saad care ; === 28 To.o18 and 0.020 mm. were the most common widths, with a range of var- | dability from 0.016 to 0.025 mm. By the latter method the most com-}] mon length was found to be 0.077 mm. with extremes of 0.057 and 0.085 mm. The most common width was 0.019 mm., with extremes of 0.017 and 0.020 m. The slight disagreement in the results obtained by the two different methods is due, in large part, to the difference in magnification used. In the direct observations, ocular micrometer qe With 1/12th oil immersion objective were used; for the camera jlucida drawing, ocular #3 and objective #5 were used. te re ‘ol Ma a Gy rl 8 ep 20 BA 9 ¥ ve a Bed ey. oS mae t Att rome: He By ee, ra cia igen hy: deen Bite a ia th wD) ae eas es tb. aati of 6 sont Wivrege al ~beaw cork a nvitos (ce! get wzameeh? fb) dee SY taiy 50 at 3g b. Echinorhynchus salvelini 1. Size and General Appearance. The body length in E. salvelini varies from 9 to 17 mm.; the width from 0.82 to 1.58 mm. In obtaining these measurements, the maximum diameter which occurs in the region of the proboscis sheath, Was recorded as the width; the length was measured from the posterio tip of the body to the inverted collar region. In all cases the fe-| males were found to be longer than the males, but the diameter in the two sexes varied less. In the contracted specimens, the anterior région of the body and the proboscis curve sharply toward the ventral surface. The body is wiv der See three regions: (1) a long cylin- ‘drical proboscis carrying hooks, (3) a well defined neck region which measures from 0.19 to 0.38 mm. in length, and (3) the body proper. The collar or neck region constitutes the introvert and is operated by muscle fibers which are attached to the collar at the place where the proboscis sheath and the collar are joined. These fibers are most numerous on the dorsal and the ventral surfaces. @. Body Wall The body wall is composed of distinct regions. Externally, it is covered with a dense cuticula which measures 0.0035 to 0.008 mm. in thickness. Beneath this is the subcuticula which contains a densely ST granular region and a region in which the protoplasm is arranged in fillar strands. The subcuticula isa syncitium possessing many ir- regular nuclei and large lacunae. The latter unite to form two lat- eral vessels extending the length of the body. On the inner surface of the subcuticula, is a circular layer of muscle fibers, This is followed by a thin irregular layer of cells containing very large nu- clei. This layer separates the circular band of muscle fibers from a Ge, ve § Oe See “iS? Poll veils ee Atpteh, ‘3 i, rat - 7 cS b, ey 17 ofyoteus ss rhhyalgale b oe ‘S Pere} wh we Bbeag ideohed: ‘ e ce a! el iser watt Bog ety ap ay Jaro OnE Seer (thre sg + che ' pasaed oan, Je, to Loui ce f od ritcngze aloe .: ou i Mii Ey “oval sel or kaa ano tone ‘ , : : Wy ‘we a. 18 @ another muscular rezion in which thé fibers extend longitudinally. Immediately next to the body cavity is a second layer of very large Hedie, ch icr in section are seen to be continuous with the muscle fi- bers. These and the cells found between the circular and longitud- imal layers are undoubtedly the cells which produce the muscle fibers | 3. Proboscis and Associated Structures The proboscis varies in length from 0.73 mm. to 0.85 mm.; the width is from 0.29 to 0.31 mm. When inverted, the proboscis is held jWithin a sheath made up of two distinct muscle layers. The sh race gis is drawn into the sheath by the contraction of muscle riven ean extend from the inner wall of the tip of the proboscis to the poster-| j ior wall of the probiscis sheath. These proboscis atbtaotiae aan tinue through the sheath as two bands, one of which passes to the (here and the other to the ventral portion of the body wall. The Contraction of these bands, the sheath retractors, causes the sheath ito be drawn farther into the body. The brain is located between the | finers of the proboscis retractors, slightly posteriad to the center jor the sheath. From the brain two nerve fibers branch off,--one pas- Ses through the dorsal, the other through the ventral wall of the proboscis sheath and form reétinacula which attach themselves, one to the ventral and the other to the dorsal wall of the body. At the points where the nerve fibers leave the proboscis, there are large nerve calls. The proboscis is armed with 26 circles of hooks, each circle co taining 8 hooks which alternate with the hooks in adjacent circles. The hooks gradually increase in size from the smallest hooks in the incomplete circles at the posterior end of the proboscis to the larg- ah eel Poe CoG w&. We 4 © . as. ; we) Wal ul i) Gata d Cae ei oGdoke ve j rf a { F ina : A. ; facel Wi se kaay’ a) Sodom \ rhs ‘ vA Leet ayy Lt . . ar + . , yi eek | ong GOS z a ha Clote tees oie , f io “ae Of’ ot sae bts acre ie Aa fi be te q é a no tr ~ ,. a f Vi ate vz ie » pao 4 & t ; | ~ “ 4 v id 4 d / . - * | Pas ABD a ee 4B i he Teo , PIOOREX ot ese agent wi tard ead/@ a apes : ¥ rM ole Lye ond tauerty sedte-eag . aieteo® BAR ed : OF SAC UN xonedd sobbea’ bs SLA Cine 2 Gil aie city aaa i | | ‘, Y. do Chop taecah-ea? of Seare aad bai. oS f arte Pi awed wf (Teh? ap vated gas Tat A ie W ‘yp vetoagss BG lat ie Hectie vs atgicdnra | arcu shh att’ od oe ae, dotion ined ion nek Leal gtd mon’ ‘eahe at ceoaeaoat wi botany rf fay Bea A rer wae ot ROS Ob ae | p cv ae ety 9 hovinbabiee ame ans 4 " tee ee ‘ oll a ea ato ree ey at emi a ee ill 31} | est hooks found in the middle and anterior regions of the proboscis. The basal hooks measure 0.039 to 0.050 mm. in length, varying with their distance from the most posterior row. The hooks of the middle | and anterior regions are 0.068 mm. in length. The hooks of the pos-| (Serior region differ from the hooks of other parts of the proboscis yin not having a basal or root process which projects into the sub- stance of the proboscis. This basal process measures 0.085 mm. in length, being much longer than the projecting portion of the hook. 4, The Lemnisci (tig: 8,6) The long, lobed lemnisci,are attached laterally at the anterior fend to that part of the body wall where the anterior edge of the col- j lar is joined to the proboscis sheath. Surrounding the lemnisci are sheaths of tissue which continue beyond the posterior tip of the or- gans and passing obliquely posteriad are attached to the body wall. ;in this species as in other forms, the function of the lemnisci has not been determined. Transverse sections of the lemnisci show tha the protoplasm is arranged in fibrillar strands. Extending trans- iversely and longitudinally through these organs are canals, similar. lin appearance to the lacunae found in the subcuticula. A few large irregular nuclei are conspicuous in the structure of the lemnisci. lThe two lemnisci are connected by a circular canal which extends a around the extreme anterior end of the proboscis sheath. 5. Reproductive Organs The male reproductive organs consist of two ovoid testes located Slightly posteriad to the center of the individual. Just posterior to these is a chain of eight spherical cement glands. Immediately re \ vA Vy OCC ame Aga Heke Qe ee D Q eM by b| ‘ wi ee Pary ka Ane * isc wy. rhea teed Jeon hie Hig dd. AGH? ae / i ‘i a nat , oy wer ney) Mei" 1 ; F: S44). , Coon a tage 8) 3 : : r. O ctepecon niehors Leedt ? FS Sn : | f jld Se yes spat wet 4 \ % x t wv | TA! ‘ ALY " v ad ' _ bas ors fares bed us \ } 5 ? L ell VErOC ece ¥e tag itor nie ethene otg aed +e ; } to alt voine wid, eh abaeyed eaves ae ‘sey ii = ~ e ne = i t ‘ oT Pan f % f * y 4 ‘ ’ J ‘ Ww \ w a ft £4 ~ ' » @ banc. sacieal sia OF erent fj a aE One I uni i 0 O'as by BOs . mt - sac t LY u fi? 2 ‘ae - Y bAT ir PoP bf (OM ote: haek Bh sisal ay | ING ! i. weed cae! > felt WORSE) SMRRENS Om ' i en Se. eV POs Oy Cie ae } ; ~ rad Jnad dtbve dud: tone (ahuias opie vue 0 ty i ert. Te ay eee ae oe pebresig ay sith) ie 5 Some EO A'SS toy Bi bales ne Ot fl : =i) a Se following the cement glands is the bursa, the first division of which | is a thick-walled, cone-shaped structure, called the Xittbental, which receives the ducts from the testes and cement glands. The Kittben- tal opens into the eversible portion of the bursa, which contains the} cirrus surrounded by the genital ganglion. About midway between the | testes and the Kittbental the wall of each vas deferens dilates into &@ bulbous enlargement. The female genital organs are located in the extreme posterior end of the individual and consist of a uterus and a vagina. The im- portant part of the uterus is the complicated selective apparatus at the anterior end of the structure. This opens into a thick uterin tube which terminates in the vagina. The vagina is surrounded by large sphincter muscles which control the passage of embryos to the exterior. Large gland cells are also found in the vaginal region. The embryos are very long, spindle-shaped forms varying in length from 115 to 165 mm. and in width from 20 to 25 mm. The gran- ular protoplasmic part of the developing embryos is surrounded by three membranes. No ovaries were found, but egg masses in all stage of development were numerous in the mature females. The embryos were measured by direct observation using #2 ocular in combination with 1/12 oil immersion objective. Bh writ OP a: Creat fee etl otra benan , oo. viet icaweo Boe cater om ed wit abet Res ; ia : & é 4 eb a we 12 £ ve PVEG oIdiexees ) bial ot \ Mi ets a bevel was 1a! TAP Mey bal fi S20 S6,eaegeRee ke yet ae ; a eJaod sit ol eiredgo ace. To mae a? .. ui bw 620 ob @Qetaniwaiaaa in’ Yeog, COA te PORsaae ote oft 4 L ¥ ? V4 CALE S32 ei éu Dawhe: sey ie | tio’ otge bap snwel ee all et we Sg ‘ eee AF a) Boot omen ure ts 7 mins. al fuou Mh eclen solieyegade ) Ovttod io a ema en SE PES Te Me a ET” TABLE IX The size of the embryos in this group seems to be of enough im- portance to warrant a detailed study. The following table contains 7 the measurements of embryos from two mature females of =. coregoni. The measurements were made from camera lucida drawings for which ocu-} ~ lar #35 and objective #5 were used. The results were checked by mak- ing direct measurements of embryos from the same individuals, the combination of #2 micrometer ocular with 1/12 oil immersion were used for these measurements. Results are recorded in microns. Individual A Individual B 20 18 ris 18 81 81 70 80 81 83 80 78 85 83 83 80 80 i 70 70 80 81 73 78 83 ae 80 67 MMM MM OM OM OR OR OO OM Pd od OS OPM Pd GOS oO Pi Pa Pd Pd Od OO Od OO Od OO od OS OO od Pd dot Po Pd Pa 4 Pt Od Oa OPS Bd Pd Oe Od Od dO Od OOS OS Sood x x x x x x x x x x x x x x x x x x x x x x x x x x x x J ( ry h ¥ Rs bts ; ; d 4 me y's, te j 7 ie J ‘ gh id or ¥ i wa ute " ’ ‘ a ne wn acvitdig ore my: haon ear. ce eptsue ; | is rl ya gésoo' * oPvesieerlys ee % 4 bi Lerney VE eR Lor ce wat hc ween un Ve ee o7eW ytd. 20 cdaibipe cies 9th f lf y a Cau i* ree. i y lof 2.36 UF > S | G. » eo as a e oe - i * a dy Mate Ui at). ce : Ni x 7 } & ‘ of nas eo 7 9% a) ae oe “, . Roe | 1 L * ;} - oe oe a : he yi a 4 DI % 7 r ’ aie? 4" ; } ‘ e e's ’ ne aA , cs | ay ae ¢F » 5 i ‘> or 64 . gs ai ie ns fe pt ae 2 pelt ot Oe pe ae ae . an Se mn _ TABLE X Measurements in microns of embryos from a mature individual of E. salvelini. Measurements made by direct observation with the aid of #2 ocular micrometer and 78 objective. 163 x 85 128 x 2a 135 X 2a 118° x 22 155 x 22 150 x 22 160 x 22 136 %.25 258 x 20 143 x 20 130% ad 143 x 20 DQ x 25 130,.%..a0 150. x 25 160 %. 20 fe0 x 25 143 x 25 150 x 22 140 x 25 140 x 22 143 x 22 140 x 25 160 x 22 £50 x 33 140 x 25 160.x 26 133 x= 25 50 x 82 153 x 22 147 x 22 147 x 22 : 2OO-x. Ba 150 x 22 147 x 22 143 x 22 145 x 22 140 x 22 133 x 25 147 x 82 165 x 22 147 x 22 145 x 22 135 x 23 55 x aa 145 x 22 143 x 22 130.x 25 las x 22 145 x 22 140 x 22 150 22a 145 x 22 143 2.85 L5G.x 26 140 x 22 150 x 3c 128 x 25 135 X 2a 140 x 22 too x 2c 140 x 25 143 x 20 1355 x ae oo x 25 50: x 325 160 x ‘ac 156 x 82 140 x 23 tga. S25 143 x 22 145 x 22 163 x 322 145 x 23a 145 x 22 168 X Bo 150 x 22 140 x 22 158 x62 147 x 25 go6 x 23 145 x 22a too) XZ ‘20 145 x 22 dos x 25 169 x 322 147 x 22 L50. x 25 138 x 32 Lio x oe toe x°3s5 165 x Be 143 x 25 L50..x% 35 145 x 28 155 x 22 147 x 22 155 £26 147° x 22 155 x 22 ie xX 25 eR ee ne a ” ‘= J. 1 i % ” * \- \ - Me \ ~ & en . ‘ é < ‘ \ ~~ ' 4 y iL wh ¥ we d ' LE vd ebin etrewssieaet ? j ‘ ‘ia iis ~ “he : - 1% bas b we £ Wt “iA me TO! MoS Le RE Bt cones Loe. v6? emer Otay SHO HOD ee a ee tee bs bs Pali be Fe 45 Pee Vie fs brn a on 5h ' bt Ie 3 ve i t we 4 The . a ~s » or of wad ue *” § vt. met y a ~ <3} Slt Ge fa bois tot “or? . fy 35 EXPLANATION OF PLATES Plate I Representing the Morphology of Echinorhynchus coregoni surfaces. Figure 32. Section of body wall (x640). a, subcuticular nuclei; b, fibers in circular muscle layer; c, fibers in longi- tudinal muscle layer. Figure 3. Tangential section through subcuticula (x640), showing the irregular nuclei. Figure 4. Hook of proboscis (x640). a, from a middle region; b, from basal rows. Figure 5. Entire animal &57), with part of body wall and proboscis | sheath removed to show internal structure. a, collar or neck region; b, circular canal connecting the lem- Peete a. fatinaguia: @, proboscis retractor muscles; £, proboscis sheath retractor muscles; g, testes; h,. cement glands; i, Kittbeutal; j, genital ganglion; k, Figure 1. Proboscis (x90), showing hooks of dorsal and ventral adhesive organ; 1, cirrus Figure 6. Proboscis (x85), showing relative size of dorsal and ventral hooks. Figure 7. Embryo (x890). SUVA GOR 1 van to curul ot? Baste ozt: .2 . (028%) siheoddea to 2 ‘ ovitelim gutvode (bie) ele ot Snes rer ees ‘ ] ITAL? TO WOETARAIGNS ae So. dread dy te en tata f i ibapeds see yt ebbely 26 ot = 4 ve : * ’ ix u me ’ Du mae M ae \ 1 dial tov yiteode YC0Gm) ehugodort . Omi) Liew yee MOL eG @ ei oiomn hyo fe Bt eeecrt of a reysl dit tiiEeal bos seve Moos? seetoae Lauipsat a . to lonc eeleem me be Fy - 1 WOR, needs ao Teisowr se i ge i< ‘Oot ee . aeih A aA. jerowt ut coe 1 a | 4eluOmnees Bf re | asi DO eg ree tolged) Let a (OGGx), oxxead ~ ki am 36 | Pilate II Representing the Morphology of Echinorhynchus salvelini Figure 8, Optical section (x90) through anterior region of body. @, proboscis; b, lemniscus; c, one of the large ir- regular nuclei of lemniscus; d, proboscis retractors; €, nerve cells at base of retinacula; f, retinacula; &, proboscis sheath; h, cells associated with longi- tudinal muscle fibers; i, proboscis sheath retractor. Figure 9. Embryo (x890). Figureto. Hooks of proboscis (x640). a, anterior hook; b, basal hook. Figureli, Proboscis (x285). ot ae Eo re a es fs esseodotqd .£ /tamecls) 6foeue mess er ‘ oo ee ee aief¢ ore (dot Yo, YypoLodgzex ons gait ‘way Jp tod pdt COE Ree RRL ICG efo .0 . -; euGetomel 7G). io LOB a RRR alk yyenakt, Smead . Lo .be Leu te “ ) a Cer ta effet orien , i Liew «4 / yhteede pt oscoeey an (qaex) oe ' fo # 7 Ls vi a2 Oeed = % 7 ie ar ay we ier a 4 iy 4 Wan er me =! te D ye.) wo ar Ay Acknowledgments The writer wishes to recognize the valuable aid given him during this work by Professor H. B. Ward, under whose direction this work was carried on. Dr. H. J. Van Cleave's many helpful suggestions as to technique and proceedure were invaluable and the writer wishes to express his sincere appreciation for the help given by his co-worker in the group of Acanthocephala, in the University of Illinois. . 3 eV .\ . .20 nad’ beketee Car eae vbasconq bab evptadge? of ae anon strong betwomloa th j exsihsoods oF sacdeie Tasli¥ pag i A ; *. +s 0. .H soenetord vd sar sida >) * saoule sin sasra7te og setuiv ehh be ttn ett a) t6capeeo eh ge eae ie ' yetombkEil to eshese rs | ~ 2 oi A Literature Cited Graybill, H. W. 1902. Some Points in the Structure of the Acanthocephala. Trans. Amer. Micr. Soc., 20: 191 - 198. Leidy, Jospeh 1850. Contributions to Helminthology. Prod. Acad. Sci. Philadelphia, 5: 98 - 100. 1851. Descriptions of New Species of Rntozoa. Froc. Acad. Sei. Philadelphia, 5: 155. 1852. Contributions to Helminthology. Proc. Acad. Sci. Philadelphia, 5: 205 - 3210. 1856. A Synopsis of Entozoa and Some of Their Ectocon- geners observed by the author. Proc. Acad. Sci. Philadelphia, 8: 42 - 58. 1888, Parasitesoof the Striped Bass. Proc. Acad, Sci, Philadelphia, 40: 124 - 125, 1890, Notices of Entozoa, Proc. Acad. Sci. Philadelphia, | for 1890: 410 - 418, Linstow, O. von 1901. Entozoa des Zoologischen Museums der Kaiserlichen Akademie der Wissenschaften zu St. Petersburg. Bull. | Acad. Imp. Sci. St. Petersburg, 15: 3271 - 2928. Linton, Edwin 1889. Notes on FEntozoa of Marine Fishes of New England, with Descriptions of Several New Species, Rep. UV. S. Fish Comm. for 1886 : 456 - 542, 1890. Notes on Entozoa of Marine Fishes of New England, with Descriptions of Several New Species. Part II. Rep. U.S. Fish. Comm. for 1887: 719 - 882. i i: bested pouty A v. bo arts ae arlt i i) @etiot bs bel ~ 18 ‘os ,» 000 L08M « THR: 8a : Fa bord .vaelodtdtmieh of /analigeerieee nae OO. + 48 2 stetete backs ‘a selosal wok té snotiqt1oRmll. . ra cal +3, wtite fe be lta: pies i hoe. Yoo »¥god state oF aaditudiqgass sae OLE, = GOR 3 Seeks iq te behhaa a 6oot0% thei? to e208 Ive posctaas te ehaqomyel he 268i } sbOG 3 . ,.oOf* Pye Sere o yd bo veges ‘re Me ih 66 — Sh ch el de tsa ae oul LO : . td ,seni beahral oils tooratisazad | a f 32 ST. 28 Nae itn! LA (cord =, acnedaa Te vanthot re BOR « OL8, 2O08L 40F TOV w i »flvk .yruderece® .7@ ve ned tetgonitel) 7oD a enepeeas 606 ~ S96, 16f 2) ‘ HT S6Sed |. 26 ..200 om e098 sae 4 he oa aiwiil: ar si ae kel dede ft. erty em he agnor ate wogn Bef oS .9ee fe ee ee (etuve® to waotegt or age he 62s A894 REL Kot al ab naet. id by yi ) uy at weteods welt Re eouda tt Sale ee ho bem am qrproty has naa salh 39 Linton, Edwin (continued) 1891. Notes on Entozoa of Marine Fishes, With Desceiptions of Hew Species. Part III. Rep. U. S. Fish Comm. for 1888 : 523 - 542. 41892. Notes on Avian Entozoa. Proc. U. S. Nat. Museum, 15: 87 - 113. 1893 .0n Fish Entozoa from Yellowstone National Park. Rep. U. 5. Fish Comm. for 1889 - 91: 545 ~ 564. 1901. Parasites of Fish of the Woods Hole Region. U.S. Fish Comm, Bull. for 1899: 405 - 492, 1907. Notes on Parasites of Bermuda Fishes. Proc. U. 8S. Nat. Mus., 33: 85 - 126. Lthe, Max 1911. Die S&sswasserfauna Deutschlands. Heft 16, Acantho- cephalen. Jena: 116 Marshall, W. S., and Gilbert, N. C. 1905. Notes on the Food and Parasites of some Fresh Water Fishes from the Lakes of Madison, Wisconsin. Rep. U. S. Fish Comm. for 1904: 513 - 522. Marval, L. de 1905. Monographie des Acanthocephales d'Oiseaux. Rev. Suisse dé Zool., 13: 195 - 387. Prota, Antonio 1905. Gili Echinorinchi dei Pesci. ATch. Zool., 3: 149- 214. 1907. Contributo allo Studio degli Acantocefali dei Pesci. Biologica 1: 377 - 419. 1908. Gli Acantoéefali degli Anfibii e dei Rettili. Arch. Zpol. 3: 225 - 260. 4 cn ee es a aan a es ry ’ j pts [ >| A, TEOO U ‘fri eeq ¢3 Ve Leoce AITeCAa Beh SLAGATEC nom 20 ¥ - eck 1a .» fons, ef. sun bee a id ited I hget Listnzesineah it A, oh id SRT PE EEN HE , ad bei TTL YT ri 1 eitta to Poxusee 20 of ’ peers r 35 * c¢ } oie.” ee a Poet . y ‘ “at FES Hie eek ¢ A be ey er ve We PV OE 5 LG, ° > P. * ary SN hth i 6 _} * * 6 * Rt oft eae Ake ¢ ay Viz +p Af . ot . sg Rae S) alk O* 98 ot) 4%, “ee A “\ 4, Se ~ WY 43 + iat * Soe 6 . g f ane ‘ “" , Wy “8 joe", SN \ fGA “a . RS » * ee ree * ¢. 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