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Sishit saree ihe \} tas uae if} f1reanysy PSHGTY yersetee ; H IhittHS ile HASb SUPA pePERPHADSE ttt THeesede rtyit FipeeePPRTG LE SVERs Psa see apes Segaeeeiecage PERE PATERERSE ShGFe eee STE TESRAATLIE SHUSTER SST White fit SbPIALIERAStatI EL ia i itiabaael 5 ‘ PIPPESSEEOEE EPEAT eyEpyseyy babe eee epehingseasist SUpesyi bees SEPLSE EEE sey SPEED) seesesee andy tif Wppisees ; } SUVPPPSST SRT IELEER } Ths} { } i i eet ee i) ESDSENSE Soseyye SU ViSSeep TUES teyetthel py betepyip? un fh reyaies ih SeeepSRN TERE Hi DORPATELBRANST ! rr ! ‘ ‘ FIAT Sreeresu epee SUPT HEES Tits af See bepEApEAE pty bE } ith ipiht Sethi RULE PORT ELIG! sit ‘it PePAREARS A Teh iyhit RS ARES SSeS fina, tinea nga gg FOF ae eS phe HY RIS NEE , i Ut oie ie M4 ip th ” iF “~ a, i bag | al J Bas PU eaeY Ue he Me SY ees rere ine MT ly oy Ne, Ae ee hag Me Bets She A AE thes id AE ay iy) L my { > w \ sf yey. P - fi iia ' t PRN Ce 78S GS46 Bas ss vet Be essen. AND NATURAL HISTORY SURVEY OF MINNESOTA a (V } HENRY F. NACHTRIEB State Zoologist SECOND REPORT OF THE ote ZOOLOGIST ‘INCL UDING A SeNeCRP eS ES OF THE ENTOMOSTRACA OF MINNESOTA ZOOLOGICAL SERIES II A 4 442787 NOVEMBER 1895 SAINT PAUL MINNESOTA - ST. PAUL MINN.:! THE PIONEER PRESS COMPANY ‘ Res 1895. ‘ / CONTENTS te insides sislaiwhin's's.c/6i0\a =is\evin's ciaivjsie'm siacinio\s,cocsinastelaisGtinesecassinecSeve¥etosiececescaanen'sd ee scerccccccccevens es of the Entomostraca of Minnesota.........secnevsersessceconscscesceesessen seseseens _ Editorial TIMBRE eee ee cai ve cine aciv'cbe cDa a bas Se cine ad Oak Poe ee ea cieetioce Meese dedvtianitedastee ee TO Fania Meant et rete WP MERIT ASS Se PODS BY EY. cre nel Se Tnx : en Marmiane te the Teportiol 1884... snipersccccole Sandoceescudeeccaccecacsocosedeeyooscnsadeevess Bibliography... Mike neon td Shanta) chan teban Jap saplene nag te nny odes demain neste Soe he saaae saci Order COPEPODA—Part Lok os ccamentcec Taaesaes Lewes ieee ne toa haae Aas eee _ - Family Calanidz................. sateen Ano e eee thes Utiaa aGAes clean geet em ee GETESE MN TVON OC ATSAIN TIS occa’ cocuoss scp oedvicccue ssn cesese apanee tecearek eels es da caeee Pee ENR NOTE MO RAW oS. co ct seach cod od'cs cauied oh alas Wledae Ra Mtens Tato Caos Abak wens me ESE DO-DLAPTOMUS, cssscastseeesot'en Seen aes apt eset cae Weroeeeehenae “(DIA PTOMUS)..0+.<-. sachsen dnires esd vanclexsPnaeaeo es tose Owe ieee beste te A ER OLMAS i accecectscnesasdectetecceds ofodastattece ey asa Manges dsvenseaa te rceeee ie ae Spa ETUE SEDER Mo .= ns.) 2521 cu. bap Sagdde noes ee eaes RNs a tI Ni aa ANP TRUREIID A: 1s 2..dcacedasebeadetececas estes bee a cea int ae Has, 2 EPI Vy : ee EO SPE ANITTCUM veasesonciseseczecelageoe tes pee a: sO toga SavslSesceceeaseocede Family Cyclopid2.................. alee bidcueseathetebeckateete eens ESOP ANE os, Be oe Genus CYCLOPS........ sil sai Sacidlees Cobeseeeeam labs mrac atoms Wiseeneres Me iets, ae ‘Family Harpacticidee.................0.00 Sie bene Te tesa d teins hehe: Sub-family CamthocCamptin2ad...........0: cece sescesveccssvecesacssvecscccescccescses COOH OA NTEOCA MP TUS 50). sos cdod scone: dacscwsaescoesesh wed tiecea ne te ot Ease # pen PAUENVET MVC TA sessec avec cases Sie ste aeeAeeah laa to sies waciet eden nee sak ae eee oes eR VICMR GHIA ssa ctychcsthisesctstes aut scecs ee eet ee Rac attpetbcs Pak tonteaains Ses eee Re oiter OMAP OCHERA—Part 11. ..00.0..0.cccscsysesestenserransnecenetsonecsene beth gee SSL Ive Ag 1G 0 Ie ee ee a aab Ogake Senshoudeae CRAB Fad ee? >i a ae tte CG ETIAES SO HIVAGG: seniors sccicsacatlonewunes’ Deeaniemciee HE ee: Pee OER GAGS ts Ph Pe Pe ePSHT DO, SUDA +ss.sssacs pihascdtgicear Segoe itsaat ocne ce epee noe ee eee Peer eM Le LNUN OSU IAT vcs ao dcees cctoeeaes rastaws clsantteuis ontenaeaete Se era ve: Prem AWEONUESIS >. 26.55 ccacst success SFaPd aah sacon eho ceeessst ech cseie Sic cere Family Holopedide....... distbesipeneessohepencteste, nated daagvendaadinesen ceean cement PreMUUine PLOT AVENCISHU DE oy nat naa cnaaaes soc arevatpaeekésaadeeleustsdocnssncevanss senadebe dagnae \ 1vV CONTENTS. Family Daphnidze................. pecitests iavhctadareeit eden terse sdatacte eaters AG ty ar Goris MONA \ycscnpeacdiccnickveptenys An tengienleeee eA pein saate vieedaeaetu see )s tes ann £6.) MORAN APHINEA, « J. .ctllsinOo0 dens tespeaseh teat taae ot aE sehece cpt OR cae *e., .) CRRIODAPHNTIA, <<.c.ctscabesss. Rebate ckatens toate praeg cainevasetp does hye EOE % S*-*) (BCAPHOLEBERIS)...,0 vuatsahestcetacuee teecevs tetint Pecsaee ete eateed Seve, ACE AF S SIMOCEPHALUG:sc../.caph ieee sn veesdughtechvant fuapeceineitens taal secures oi nd De #86 DAPHNIA 2 linus. cos beerteeeh ath eer Seu Ca en Cate amas | eee am coos 181 & Family Bosminidee .....ai..<.. una. aga ees pst cendives olin 206 Nae Gepitis BORN A. <..50-udaboncons apo cbsis agers pone ae Secelicsss «iene oo, ROB aaa Family Lyn cod aphid oe... ds (issaseasss cdepceatea oka, Me odabaeenn a eae -. UG eases Genus MACROTEIRIE ...05i.L.cccaces hosts. ba 000 paebe tee yes oo oeute cele Pe eee i Sit 33 FRU% aC.) AMET OMPOIEA os «te ise a oem kaa ck ee ‘os SRR SAE cba AS o> pons MON ate eaten ‘¢.\ “EYPRERBLOORRUS: vise buuseierhendarmecas: sae aap ae Ree ECE acto Sera: een A° i DRBPANOTERIR... di costoe Vavcndecteesscnatadeght ec cty:eeeen seine ae tc Rtaanaee 217 o AGANTPHOLRBBIRIS! seat - ime nadee Seen ‘s JLYOCRYPTUS....... nocadedal ante ablase sd cle Bovaslesd MERSN EE eae Cnn 220° ; Family Liaymeeidl a.....:.,2.502.0svedeosecsseauslAtnph deceekinds stan tuameegn i nae eae seo ROU ee Sub-family MuPy Cereiwmge yf. si.5.: ies cnc docsnoecdees nak avevaieles ooze. ueateaeys ae weee 225 a Gents BURY OBRCUB 2. 2 yesec.s saa svedeccbacsdevoncantunbasaste ee nhaeeeys Soe SOG Pre Re Sub-fimily Lynmeein ge s23. <1. vos viscees aie ee eee eke ‘ Genus) CAMPTOCHRCUS<....c2crstcoucuoctees sete essnceveecaseaneraceee Fanaee ae desaesec cement 5 Sub-genus' ACROPHRUS:.\ccssne ioc sesescecscuetoctectous sete sige? tons eeerctees p aeaeeem . 227 ae CAMPTOCEECUS,.csohs sescescqusectsnesct senna €T¥eesaseenssiansenesoossneene i Ee ; he Grehtis ALONOPSIS.N cacy: cenccdaducepadecteseaeeiass aeetee EES MESES 'p) rom Be - oxsbaue POL P tf", LEM DIGUASS canadeovs enconaetade ais cpinnasient tea upels Seaasva Seat eisai Serves QOS ¥ $s.) GEAPTOLEBERIS 4, ..02-:40desde sha ceeepins lussctateeneine a eotee 235 ‘ SS. DUNERVEDIAS 0 0o. ce .cceitan cue tcece teens os spins enn ee au ae einen ss a 236 < 6) MOY NOBUS. vesen. See prec e eee Sea ee eth cata ae hie yg Re HOD-CeNUS ALON Arcee seek lan scedist ccdaweavecetoeeees eds sesuctidoepad tox eseeeeneee 238 ‘ * Bechion (AS ALON, 3. spanuksleepee anon aasnte St. Paul. The Hon. STEPHEN MAHONEY, M. A............cscescccccerscecceesersescscncesones Minneapolis. The HON: WALLIAM LIGGETT. «.ic.. cock ssenesctevescussuee opavis cas sales enaWas dslen'etsysesecnuiien Benson. The, Hon: OZOBA | P. STEARNS...» ove sc smsecs sa cowss seas dbeenetecvance Pakest ne slectyesiy es -aneam Duluth. The HON. JORLZP.AABATWOLW s. c2:sacts-caocctes step addins sat sot panes meavasereeecined Northfield. The JON, SIDNEY. Ms OWENS. <0s 20 sacionsep seats aces sanetenisurs ger exeaeewares sane Minneapolis. The HON. WIGGIAM) Hi Y AGB. ys 0. Vics Glesess ccuuss cer eese tentrcbeaen ceavackans: dosienaeae Winona. EX-OFFICIO. Cyrus NortHrop, LL. D., Corresponding Secretary....... fd eo a ehsionte Minneapolis. The President of the University. The HON. KO NUTE. NEGSON% i025. cstacsusieenycns ston ence cupaetesces teste ctaets asain Alexandria. The Governor of the State. The Hon. Wi W. PENDERGAST, (Ms.AUi.c.2505seciconssssotescuscnuass fp osbeNaotanens Hutchinson. The State Superintendent of Public Instruction. REPORT OF THE PLATH ZOOLOGIST FOR 1893 AND 1894. Shortly after the distribution of my first report a kindly criticism of the brief reference to the early history of the survey was received from a gentleman who formerly was a resident of Minnesota and took an active interest in the work of the survey. In accordance with the assurance given to the critic I take this opportunity of correcting, so far as possible, the feature which to him seems unjust. The statement taken exception to is the last sentence of the second paragraph of the ‘‘General Introduction,’’ reading as follows: ‘‘For many years the Natural History Survey existed only in the wisely formulated law, for which excellent and comprehensive law we owe thanks to Dr. Wm. W. Folwell, who was president of the University at that time.’’ It is contended that the credit for the survey law is almost entirely due to the Honorable John 8. Pillsbury, and ‘‘that the truths of history require that those who know the facts should demand that credit be given where credit is due.’’ It is particularly stated that the Honorable A. J. Edgerton, now U.S. District Judge at Sioux Falls, South Dakota, while Railroad Commissioner of Minnesota, dis- covered there was a balance of a grant of land to the state, called the ‘*Salt Land Grant,’’ and suggested to the Honorable John S. Pillsbury, then a senator from Hennepin county, that this so called salt land ought to be set aside for the survey fund. The suggestion was taken up and after considerable hard work the end was gained in ‘‘An act to aid the geological and natural history survey of the state,’’ approved March 10, 1873. To this [reply: 1. There is no conflict between the bit of history given by the critic and my statement, which alluded only to the orig- inal draft of the law creating the survey. 2. My statement was based x REPORT OF THE upon the published history* of the survey. To this I have never found nor heard of any recorded objection. Of those who have worked for the interests of the survey the Hon- orable John 8. Pillsbury unquestionably has been the most persistent and unselfish. But with no thought of an historical review the refer- ence to even such bright lights did not occur to me. No one can desire to see honor given where honor is due more than myself, and I trust that, if the published history is wrong and unjust, those who know the faets will publish them. The disbursement of the funds available during the past two years I shall not tabulate here, as the accountant of the University will give full consideration of that in his report. During the past year the Survey lost by fire its boats and oars and a few minor pieces of apparatus that were stored in the ‘‘Coliseum.’’ The invoice of the Survey property will indicate more specifically the condition of the apparatus. The field work has been carried on as much as the meagre funds would allow. Special attention nas been given to the fishes, the birds and some of the invertebrates. During June, July and August of 1893, a party of four University students (August Bothe, George D. Head, Frank Manson and Clarence L. Whitman) collected material and data in the Gull lake region. The principal lakes investigated are the following: Gull, Round, Long, Mud, Hubert, Kilpatrick, Upper Gull, the Fishtrap series, Edna, the Cullen series, Mayo, Sibley, Lone, Twin, Pelican, Half Moon, Little and Big Gladstone, Sylvan, Edward, Bass and Mission. The principal streams in this region were also more or less thoroughly investigated. During the same time another party of four University students (John A. Crecelius, Francis B. Sumner, Clarke Barrows and Charles Topping) were carrying on field work in the region between Park Rapids'and the headwaters of the Mississippi. The principal lakes here visited are: Fishhook, the Elbow series, five of the Crow Wing - series, Itasca, Elk, Bemidji, Cass and Kitihi. The material collected by these parties is stored.in Pillsbury Hall. Most of the material has been assorted, arranged and catalogued so as to make it readily accessible for study. The fishes of the several col- lections are being looked over by Mr. U. O. Cox of the Mankato ~ normal school. Mr. Cox is also at work upon a preliminary report *The History of Geological Surveys of Minnesota, by N. H. Winchell. 1889. Bulletin No.1 of the Geological and Natural History Survey of Minnesota, page 5. Final Report of the Geological and Natural History Survey of Minnesota, 1884. Vol. I, page 106. See also the footnote on page 29 of President Folwell’s Inaugural Address, delivered Dec. 22, ABBY s and printed immediately after. ’ « STATE ZOOLOGIST. xi on the fishes of the State. This report we hope to have ready for the printer before next spring. It will be issued as one of the bulletins of the Survey. ‘The ornithologist, Dr. Thomas 8, Roberts of Minneapolis, made a trip of ten days into the southwestern part of the State during the latter part of May, 1893, and one of ten days into the Lake Vermillion region during June, 1894. Both trips were very profitable, and dem- onstrated conclusively that nothing but a visit of the ornithologist to the varions important sections of the State at the proper seasons can gain for the Survey the information and material required as a basis for a reliable and satisfactory final report. The wisdom of prosecuting the ornithological work with a view to a final illustrated report is fully vindicated by the great interest taken in the ‘‘Notes on the Birds of Minnesota,’’ published with my first report, and by the numerous inquiries as to when the final report on the Birds of Minnesota is to appear. The edition of Dr. Hatch’s ‘‘ Notes” is already exhausted. The demand for this publication has been gratifyingly great, particularly in the State, where, I am glad to say, the great majority of the books have found interested owners. The distribution fund for this report was insufficient, and the last three hundred or more applicants were obliged to pay the transporta- tion charges. The willingness with which these charges were paid has convinced me that all persons really interested in such reports will gladly pay the transportation charges on them. In view of the facts i would suggest that hereafter provision be made to pay trans- portation charges on only those copies of the reports and bulletins sent to our ‘‘exchanges”’ and to citizens of Minnesota. During the past summer Mr. C. L. Herrick, a graduate of the Uni- versity and Professor of Biology in Denison University, with the as- sistance of Professor C. H. Turner of South Atlanta, Georgia, com- pleted a report on the Copepoda, Cladocera and Ostracoda of the State and tendered it to the Survey for publication. The demand for Mr. Herrick’s report on the Crustacea of Minnesota, published in the Twelfth Annual Report of the State Geologist, and the many import- ant and interesting problems connected with this group of animalsare a sufficient reason for publishing a revision of the report for 1884. The report will also be of special value to our teachers of zoology. A few purchases have been made for the museum during the past two years. Of these may be mentioned a young bull moose, two deer, one wolf, one black woodchuck, and several smaller mammals. During the same time the museum has been enriched by valuable donations, of which the following are worthy of special mention: , xii REPORT OF THE From Dr. W. 8S. Strode, Lewistown, Ill., a collection of land and freshwater shells representing about fifty species. From Nathan Butler, Barnesville, Minn., the bones of a large moose. From Mr. Benjamin LaMere, Hickory, Aitkin County, a few mammalian skulls and skins, From Mr. D. D. Stone, Lansing, N. Y., a collection of eleven sets of bird eggs containing forty-two eggs, of which five sets are accom- panied with the nests and three sets with the skins of the female birds. From Mr. Denis Gale, Gold Hill, Boulder county, Colorado, forty- three sets of bird eggs containing one hundred and ninety-seven eggs, of which twenty-two sets are accompanied with the nests. Also the skins of eight birds and three small mammals. From Mr. James Hobson, Ann Arbor, Michigan, thirty-four mounted skulls, nearly all of them the skulls of different species of birds. From Mr. A. D. Brown, Pipestone, Minn., three bird skins of special value to us. From Dr. C. J. Cooke, New Richland, Minn., about one hundred bird skins, the majority of which are from Minnesota. From Mr. Franklin Benner, Minneapolis, his entire collection of bird skins, eggs and nests. This collection contains about six hun- dred and fifty skins and represents about two hundred and _ fifty species. From Dr. Thomas S. Roberts, Minneapolis, his entire collection of bird skins, eggs and nests. This collection contains eight hundred and fifty skins and represents about three hundred species. In the Roberts and Benner collections the University has the most complete and perfect collection of Minnesota birds in existence, a col- lection that makes the ornithological room of the utmost importance to the student of the ornithology of the Northwest. For the excellence of our ornithological collection we are especially indebted to Dr. Roberts, who was not only the first to present to the University so valuable a collection as his own but was also instru- mental in inducing Messrs. Benner, Cooke, and Brown to give us their valuable collections. Dr. Roberts has also given much of his valuable time to the arrangement of the collection since it has become the property of the University. In the tedious work of relabeling aud arranging the collection Rev. H. W. Gleason is gratuitously ren- dering indispensable assistance. In the field work Mr. Thomas Miller of Herron lake has gratuit- ously rendered great service to the ornithologist. Several amateur STATE ZOOLOGIST. Xili ornithologists residing in different parts of the State have very gen- erously offered me their assistance in the prosecution of the ornith- ological work, and it will be a pleasure to properly credit all such assistance in the final report. All acquisitions are properly recorded in the accession record of the museum, the record containing the accession number, the original number and all known data relating to each specimen, whether pur- chased, collected or donated. The ornithological material is recorded in a special record. A card catalogue of all this material is now being prepared, and when completed will make the material readily accessible. Other collec- tions, such as the collection of fishes and insects, will be similarly recorded and catalogued. It would be unpardonable not to call attention to the cramped con- dition of the zoological museum at this time. Some of the valuable collections noted above were presented rather reluctantly on account of the insecurity and insufficiency of the quarters. The insufficient protection against fire and the lack of room for proper display of speci- mens have diverted from us some most valuable material that is now the property of museums in the East. Collectors, and particularly specialists, will continue sending their best and rarest specimens to other museums just as long as we do not offer a safe and adequate de- pository. A zoological museum in good quarters and properly taken care of soon acquires material of great general interest and incalculable scientific value,—material that costs more in both time and money to collect and prepare than any other, and that often can not be dupli- cated at any price. It ought, therefore, be housed in the safest pos- sible building. The zoological museum in Pillsbury Hall has, without any special effort on the part of the curator, already acquired an amount of ma- terial that simply cannot be properly displayed or arranged in the present quarters. Hundreds of fine specimens are crowded into cup- boards, drawers and boxes. In this condition the zoological museum must be unsatisfactory to the visitors and discouraging to those in charge of it and desirous of building it up. Moreover, our opportun- ity to get representatives of those animals which are rapidly disap- pearing from the State is slipping by. If the museum is ever to offer a true survey of what the animal kingdom of the State is and was, adequate and safe quarters must be provided very soon. Very respectfully, your obedient servant, HENRY F. NACHTRIEB. GEOLOGICAL AND NATURAL HISTORY SURVEY OF MINNESOTA HENRY F. NACHTRIEB State Zoologist SYNOPSIS OF THE ENTOMOSTRACA MINNESOTA WITH DESCRIPTIONS OF RELATED SPECIES COMPRISING ALL KNOWN FORMS FROM THE UNITED STATES INCLUDED IN THE ORDERS COPEPODA” CLADOCERA § OSTRACODA By €. L. HERRICK and C. H.. TURNER NOVEMBER 1895 SAINT PAUL MINNESOTA Wi Oe ae ee Fe EDITORIAL NOTE. Early in the spring of 1894 the state geologist, N. H. Winchell, referred to me a letter from Professor C. L. Herrick containing two propositions, viz.: (1) That the Survey accept and publish the present revision of the report of 1884; (2) that the author be permitted to make such use of the old report as he saw fit and publish the revision independently of the Survey. After having been assured that the errors of the 1884 report had been corrected and the report had been bettered in other respects, it was decided, for reasons that seemed sufficient, to accept the first offer, though the revision had been begun and practically finished without the knowledge of any one connected with the Survey. The manuscript was received during the last week of October, 1894. The editorial work as well as the proofreading all fell to the zoolo- gist of the Survey. The author’s serious illnessand his great distance _ from the University made it impracticable to put any of this work upon him, The work was at times very disheartening, but I did my best, and trust that at least most of the errors and shortcomings of the manuscript have been eliminated. In justice to the author the following matters deserve special men- tion: The author’s title, ‘‘Synopsis of the Microcrustacea,”’ etc., was changed for reasons found principally in the primary destination of | the repart and in the usage of some of our best and most generally used text-books of zoology. For making reference only by author and date the editor is wholly responsible. The date is always an important and often a very essen- tial part of a publication, and for that reason alone is far superior to a reference by a purely artificial number. The superiority of an abbreviated reference to a full or more or less mutilated citation is so obvious that it needs no vindication. In the bibliography the editor has supplied the number of pages, number of plates and similar data of detail from Taschenberg’s Bibliotheca Zoologica, Zoologischer Anzeiger, Zoologischer Jahresbericht, and the Catalogue of Scientific Papers compiled by the Royal Society of ‘London. Where these data are wanting the citation could not be found in these publications or could not be identified beyond a doubt. In comparatively few cases could these data be obtained from original sources. More or less gross discrepancies between the manuscript and the publications noted above were very numerous as to date, title “ag Y ap 4 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. etc. As a rule, these could be satisfactorily cleared. Whenever there was any doubt as to which was correct in part or as a whole, both the author’s citation and that of the editor’s source were given, the latter parentketically. Several references made to Strauss have been referred to Straus-Durckheim, and Sars cited with four different sets of initials it seemed clear was intended for George Ossian Sars. A few citations have been added by the editor from original sources. Those interested will not fail to collect others from the Bibliotheca Zoologica and similar publications. Under the Cladocera the citations had to be given in the original form, because the data given in the manuscript did not make possible a more definite reference. In these cases all but the references to synonyms were cut out. In accordance with the rules of nomenclature of the German Zoo- logical Society, the comma between the specific and author’s names has been eliminated and all specific names appear in lower case. So far as possible these rules have been followed in other respects. The | absence of literature, however, made it unsafe for me to touch doubt-— ful cases. The ‘‘sp. n.”’ of the old report has been replaced by the author’s name, Herrick. The various ‘‘keys’’ have been reduced to a uniform plan, and several of them have been compiled by bringing the sections together from various parts of the manuscript. To increase the value of these ‘‘keys,”’ the page upon which the description of the genus or species ~ begins has been added and names of authors and other details have been dropped. The names of families, genera, etc., have been italicized in the gen- eral text. ‘ The order and arrangement of the plates is most unsatisfactory. None of the drawings had been called for by me before they were sent to the engraver, and besides the necessity of using so many of the old plates made an orderly and respectable arrangement impossible. The index is wholly the work of the editor. Professor Turner’s paper practically appears in its original shape. The key to the Cyprididz was changed from the bracket form to the paragraph form for practical reasons only. I take this: opportunity to express my indebtedness to Professor C. Judson Herrick of Granville, Ohio, for kindly looking after the engraving and printing of the plates, and to Mr. W. H. Kussmaul of Granville for the care he exercised in the printing of the plates. To the state printing expert, Mr. George C. Stevens, I am indebted for indulgent considerations and a lasting patience. HENRY F. NACHTRIEB. APRIL 29, 1895. rs its 13a a te ye AP Ree ig Po . LN ak as wap iw ts", “ yoy } PREFACH. The exhaustion of the edition of ‘‘A Final Report on the Crustacea of Minnesota included in the Orders Cladocera and Copepoda’’ has led to a demand for republication. It has seemed unfortunate that the imperfections of this work, many of them due to the unsatisfactory state of the European literature, while others were the result of im- perfect information and faulty observation or hasty judgment, should be perpetuated. The original paper grew out of studies made chiefly while the author was an undergraduate at The University of Minne- sota and was very fully occupied otherwise, and circumstances have prevented him from anything but the most casual pursuit of the sub- ject since 1884. It might have appeared that the work had served its purpose, but there were many indications of a need for a comprehen- sive, synoptical survey of this field, and the present paper seemed the only approximation to sucha work. A _ serious illness, which has greatly impeded the progress of the revision at last decided on, has at the same time made it possible by forcibly relieving the author of more pressing duties. It would have been a great satisfaction to him to have given to the subject the thorough field work and comprehen- sive bibliographic elaboration it deserves, but strength and opportu- nity forbid. In default of this it might seem wiser to enumerate only American species, but experience has shown that geographical limi- tations do not prevail to any great extent in most of the families here considered. In such instances, Calanide for example, the attempt has been made to include all valid species and a full Synonomy. In the others as full a list is given as is now possible, and while this work may not be alone sufficient to enable the specialist to formulate new diagnoses and descriptions, it yet offers much fuller Synopsis than yet published and will give a bird’s-eye view of the taxonomy of the subject. The most important aspect of the subject, namely, the biological relations of these organisms, has been too generally neglected. {n no other group can the problems of parthenogenesis and heterogenesis be so easily and accurately studied. The transparency of the body CEO UE Lol a et Ta A ite ee “ 4 * r 7 Y. « ~ s* ‘ og ; ¥ Derk oe &ehg ‘. a - a @ : ae Se mA Se Pn Am pik na ee y 6 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. makes it possible to examine vital phenomena directly and watch the effects of stimuli upon the circulation, ete., in continuo. Many curious — problems, among them bathymetric distribution and the effects of — environment, can be satisfactorily studied in these groups. Itisa matter of wonder that greater use is not made of these types in the | laboratory courses of our universities. Probably the chief obstacle has been the lack of suitable means of determining species. This we endeavor to offer in so far as may be necessary for this purpose, but purposely abstain from the theoretical questions everywhere pressing ~ on the attention. This work claims to be a report on the Crustacea of Minnesota, but it was found impracticable to sufficiently describe our forms without a rapid survey of the whole territory. I am under obligations to Pro- fessor C. Dwight Marsh and to Professor E. A. Birge for loan of litera- ture, and to Professor Charles Turner of Atlanta for many notes incor- porated in this work. My greatest obligation is to my wife, who has collated the bibliography accompanying. This tedious but most useful labor has been wholly performed by her. For many incidental aids during the progress of the work I am indebted to my brother, Professor C. Judson Herrick. The reader is requested to remember that this is a revision, follow- ing to a large extent the mould set in 1834, and therefore should not be held to the standard of a work wholly prepared in the light of our present knowledge. The third part of this paper, that dealing with the Ostracoda, is wholly prepared by Professot C. H. Turner, who has been assiduously studying the group for several years, and I feel sure that his contribu- tion will be highly appreciated at the present time, especially as no attempt to monograph the order in America has yet been made. ALBUQUERQUE. NEW MExiIoo, Nov. 1, 1894. PREFACE TO THE REPORT OF 1884 ON THE CLADO- CERA AND COPEPODA OF MINNESOTA. In presenting what may be denominated a final report of the work done in this state upon the group of Crustacea best represented and, all things considered, most important, the author must admit that the term ‘‘final’’ refers only to his own opportunities and the limitation of time imposed by circumstances. While a comparatively large proportion of all the species existing within our limits have been examined during the progress of these investigations, there undoubtedly remain many additional and curious forms to reward the search of the student. A great variation in the degree of completeness with which the different genera and species have been treated will be observed, due in part to the circumstances under which they were studied and frequently to the poverty of ma- terial. The entomostracean fauna is quite different at different sea- sons, and a complete knowledge of even our local fauna requires a long period of observation. Even the dead of winter is a favorable time to study some groups. ‘The late autumn is, perhaps, the most favorable opportunity; for then, in one group, the sexual activities are just at their height and both sexes may be studied. A number of Cladocera are restricted to this season. There are a number (how large it is not yet possible to tell) of species in both groups which are to be sought by night, though no phosphorescent species are yet known. Our larger and, especially, deeper lakes have a quite different fauna from the shallow pools and rivers. In general, the flowing waters are poor in Entomostraca. The Cladocera or shelled Entomostraca have here received a large share of attention, and more particularly the Lyn- ceidee, which are the most minute of Arthropods. This study has been rewarded with an unexpectedly large number of forms, and a particu- larly large number of species identical with those of Europe and else- where.- Professor Birge is the only American writer who has attempted this group, and his valuable work has made us familiar with the more striking new species. A few new species are included in our list and several varieties hirdly yet known in Europe. ‘The 8 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. remarkable Monospilius is among these. This animal has but a single larval eye in the middle of its forehead, and wears its old covering over the newly-formed shell till the latter is a curious patchwork mass. The attempt has been made to incorporate a brief description of all American species with those found in Minnesota, and also to frame keys for the larger genera, so that the place of a species among its congeners may, at least approximately, be found. The difficulty of framing such keys is very great; for few authors have employed the same distinctions in their descriptions, and it is necessary to select points sharply distinctive and conspicuous from the often meager remainder after striking off scattering particulars. In some cases this difficulty has been greatly enhanced by the possibility that some of the species should be considered synonyms or varietal forms. The tendency to combine questionable forms thus produced it was neces- sary to offset by what may seem a too great conservatism. Faulty, however, as these keys may be, it is hoped that they will serve a good purpose in the extent which they cover. While the limits of this work preclude much more than a systematic outline, opportunity is taken here and there to admit a word on the anatomy or development. Such allusions must be considered simply accidental, for a complete treatment of these subjects would require large volumes, and the ma- terial will be long in gathering. A larger proportion of the rare males of the Cladocera are here referred to than in any previous work of equal extent. The genus Cyclops, one of the bugbears to fresh- water carcinologists, is perhaps somewhat summarily treated. The excuse must be the condition of the synonomy. However, most of the combinations made were the result of careful study of large series. from different localities. The sketches illustrating this paper are photo printed from the writer’s own drawings, and, without the ele- gance of lithographs, serve the purpose of explaining points of struc- ture which cannot be communicated verbally. J am indebted to Pro- fessor A.S. Forbes for very timely aid in bibliography, without which the paper could not have been completed. To Dr. Lindahl, through my friend Mr. Oestlund, I am indebted fora likeservice. But my obli- gation is deepest to Professor Rudolph Leuckart of Leipzig, who kindly afforded access to almost a complete set of works on European Ento. mostraca. Professor C. W. Hall has collected, at much expenditure of time and labor, a set of specimens from different parts of the state, which he kindly placed in my hands, thus enabling meto observe the great similarity of widely-separated faunz. Mr. Lieberg also sent specimens of Diaptomus stagnalis from saline pools in Dakota. ots 8 eae cS oa ’ fee ad . a ee ned ‘ y PS xf aon as ah ae Oa x fot = he a ee BIBLIOGRAPHY. The present list, chiefly the work of Mrs. C. L. Herrick, cannot hope to prove complete, nor has it been possible to verify references in many cases. The imperfections arising from securing titles at secondhand, however much to be regretted, will not, it is hoped, pre- vent this catalogue (by far the most complete yet printed) from hav- ing a certain value to the working naturalist. [See editorial note. Dates later than 1800 are abbreviated. | Adams, George. 1746. Micrographia illustrata, or the knowledge of the microscope explained. (4 pl.) London. (Plates in 4°. London 1747. 4th edit. 1771. .8°. 72 pl.) Allman, G. J. ’47. Description of a new genus and species of Entomostraca. (Biological Con- tributions. No. III.) Ann. and Mag. Nat. Hist. Vol. 20, pp. 1-9 and 47-52. 48. On the Development of Notodelphys Allm., a new Genus of Entomostraca. Rep. 17th Meet. Brit. Assoc. Advance. Sc. in 1847. Notices and Abstracts, p. 74. Anderson, John. 62. On the Anatomy of Sacculina, with a Description of the Species. Ann. and Mag. Nat. Hist. Ser. 3, Vol. 9, pp. 12-19. (Proc. Roy. Phys. Soe. Edinb. Vol. 2, 1863, pp. 304-314.) Asper, G. *80. Beitrage zur Kenntniss der Tiefseefauna der Schweizerseen. Zool. Anzeiger. Jahrg. 3, No. 51, pp. 130-134 and No. 54, pp. 200-207. Aurivillius, 0. C. *79, Balzenophilus unisetus nov. Gen. et Sp. Ett Bidrag till Kannedomen om Harpacticidernas Utvecklingshistoria och Systematik. (4 pl., 26 pp.) Akad. Afhandl. Stockholm, Central-Tryck. 8°. "791, Ona New Genusand Species of Harpacticida. (Balzenopbilus unisetus. 4 pl., 16 pp.) Bihang till K. Svenska Vet. Akad. Hand]. Vol. 5, No. 18. Baird, W. 734. List of Entomostraca found in Berwickshire. Trans. Berwick. Nat. Field Club. Vol. 1. 87. The Natural History of British Entomostraca. Mag. Zool. and Bot. Vol. 1, pp. 35-41, 309-333 (3 pl.), 514-526. 38, Id. Ibid. Vol. 2, pp. 132-114, 400-412. 7381, Id. Ann. Nat. Hist. Vol. 1, pp. 245-257. 43. Id. Ann. and Mag. Nat. Hist. Vol. 11, pp. 81-95 (2 pl.) eta st Bits io PN cl Si woo 10 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. 46, Description of some new genera and species of British Entomostraca. (1 pl.) Ibid. Vol. 17, pp. 410-416. 49, Arrangement of British Entomostraca, with a list of species. ‘Ki Trans. Berwick. Nat. Field Club. Vol. 2. | a ‘50. The Natural History of the British Entomostraca. (36 pl. VIII., 364 pp.) es Ray Society, London. dig 59. Description of several species of Entomostracous Crustacea from Jerusalem. BN (2 pl.) ae Ann. and Mag. Nat. Hist. Ser. 3, Vol. 4, pp. 280-283. 5 Balbiani, G. Bs ’69. Observations relatives A une Note récente de M. Gerbe, sur la Constitution : et le Développement de 1’ ceuf ovarien des Sacculines. Compt. Rend. de |’ Acad. des Se. Paris. T. 68, pp. 615-618. ’°69.! Sur Ja Constitution et le Mode de Formation de l’ceuf des Sacculines. ~ Ibid. TT. 69, pp. 1320-1324. 69.2. Sur la Constitution et le Mode de Formation de l’ceuf des Sacculines. Re- marques concernant une Note récente de M. Ed. van Beneden. Ibid. T. 69, pp. 1376-1379. Barrois, Th., et R. Moniez. ’°88. Materiaux pour servir a1’ étude de la F'aune des eaux douces des Acores.. ae IV. Crustacés. [Copepodes par Barrois; Ostracodes, Cladoceres, Branchiopodes par Moniez.] Lille, 1888. 8°. 20 pp. Beck, Cour. ’—, On some new Cladocera of the English lakes. Journ. Roy. Mic. Soc. London. Vol. 3. Beneden, Edouard van. Fae. 69. Sur le Mode de Formation de l’ceuf et le Développement embryonnaire des Sacculines. Compt. Rend. de l Acad. des Se. Paris. T. 69, pp. 1146-1151. °70. Recherches sur l’Embryogénie des Crustacés. III. Développement de lceuf et de l’Embryon des Sacculines (Sacculina carcini Thomps.). (1 pl.) Bull. de 1’Acad. Roy. de Belgique. Ser. 2, T. 29, pp. 99-112. '70.! Reponse a quelques-unes des Observations de M. Balbiani sur l’ceuf des Sac- culines. Compt. Rend. de l’Acad. des Se. Paris. TT, 70, pp. 197-200. Beneden, Eduard van, et Emile Bessels. ; ’70. Mémoire sur la Formation du Blastoderme chez les Amphipodes, les Ler- néens et les Copépodes. (5 pl.) Mém. cour. et Mém. d. sav. étrang. de Belgique. T. 34, p. 59. Beneden, P. J. van. ‘51. Recherches sur quelques Crustacés inférieurs. (5 pl.) Ann. Science. Nat.-Zool. Ser. 3, T. 16, pp. 71-131. °61, Recherches sur les Crustacés du littoral de Belgique. (21 pl.) Mém. de l’Acad. roy. de Belgique. T.33, p. 174. [Title given by Herrick is: Recherches sur la faune littorale de Belgique, Crustacés. Mem. d. l’Acad. de Bruxelles. Tome 33. ] Ve ee eet Te A ENT OMOSTRACA OF MINNESOTA. il Birge, Edward A. - 78. Notes on Cladocera. (2 pl.) Trans. Wisconsin Acad. Sciences, Arts and Letters. Vol. 4, pp. 77-112. 91. List of Crustacea Cladocera from Madison, Wisconsin. (1 pl.) Ibid. Vol. 8, pp. 379-398. ’_,. Notes on Crustacea in Chicago water supply, with remarks on the forma- tion of the Carapace. Chicago Med. Journ. and Ex. Vol. 5. Boeck, Axel. *59, Tvende nye parasitiske Krebsdyr. Forhandlinger. 65, Oversigt over de ved Norges Kyster iagttagne Copepoder henhorende til Cal- anidernes, Cyclopidernes og Harpactidernes Familier. Forhandl. Vidensk. Selsk. Christiania. (Aar 1864.) VII, pp. 226-281. 68. Om Sildeaat. Tidskrift for Fiskeri I. 1876, and Archiv f. Naturgesch. XXXIV. 1868. "73, Nye Slaegter og Arter af Saltvands-Copepoder. Forhandl. Vidensk. Selsk. Christiania. (Aar 1872.) XIV, pp. 35-60. Bourne, G. C. ’89. Report on the Pelagic Copepoda collected at Plymouth in 1888-89. (2 pl.) Journ. of the Marine Biol. Assoc. of the United Kingdom. New Series, Vol. 1, No. 2, pp. 144-152. Brady, George Stewardson. 64. On the Zoology of the Hylton Dene. Trans. Tyneside Nat. Hist. Club. Vol. 6. 67. Reports of Deep sea Dredging on the Coasts of Northumberland and Dur- ham, 1862-64. Pelagic Entomostraca. Nat. Hist. Trans. Northumb. and Durham (1865). Vol. 1, pp. 29-40. 68, On the Crustacean Fauna of the Salt Marshes of Northumberland and Dur- ham. (2 pl.) Ibid. Vol. 3, pt. 1 (1869), pp. 120-136. 1 ’69. Description of an Entomostracan inhabiting a Coal Mine. (Canthocamptus cryptorum. (1 pl.) Quart. Journ. Microse. Sc. NewSer. Vol. 9, pp. 23-24. "70. Id. Nat. Hist. Trans. Northumb. and Durham. Vol. 3, pt. 1 (1869), pp. 203-205. "72, , Monographia Encopepodorum liberorum in Hungaria hucusque reperto- rum. A. M. tud. Akademia altal a Vitez-alapbol. ’*88. Crustacea Cladocera faunze hungarice. E. commissione regiz societatis hun- garice scientiorum naturalium elaboravit. Cum 4 Tab. Budapest, 1888. 4°. VIII, 128 pp. (Hungarian with Latin descriptions. ) 91. A magyarorszogi Diaptomus-fajok Atnézete. Termesz. Fiizet. Vol. 13, Heft 4, pp. 114-143. Also: Ubersicht der Diaptomus-Arten Ungarns. (3 pl.) Ibid. Revue, pp.£177-180. Dahl, Friedr. 91. Untersuchungen iiber die Tierwelt der Unterelbe. 9 6 Ber. Comm. Unt, D. Meere Kiel. Jahrg. 17-21, pp. 152-185. Dana, James D. ‘48. Conspectus Crustaceorum, que in orbis terrorum circumnavigatione, C. Wilkes e classe Reipublicze Foederatze duce, collectoram. 1847-48. Proceed. Am. Acad. Arts and Sciences. Vol. 1, pp. 149-155. 752. Id. Ibid. Vol. 2, pp. 9-61, 201-220. 52-55, Crustacea, In — United States Exploring Expedition, during the years 1838-42, under the Command of Charles Wilkes, U.S. N. Vol. 13, 2 pets. 1352, 753. 4°. 1630 pp. Atlas with 96 plates, large folio, 1855. '54-'55. On the Geographical Distribution of Crustacea. Am. Journ. Se. and Arts. Ser. 2, Vol. 18, pp. 314-326; Vol. 19, pp. 6-15; Vol. 20, pp. 168-178 and 349-361. Also separate: New Haven, 1854. 8°. 56. A Review of the Classification of the Crustacea (with reference to certain principles of classificationg. Ibid. Ser. 2, Vol. 22, pp. 14-29. Also separate: New Haven, 1856. 8°. Desmarest, Ans. Gaetan. '25. Considérations générales sur Ja classe des Crustacés, et Description des espéces de ces animaux, qui vivent dans la mer sur les cétes, ou dans les eaux douces de la France. Avec 5 tableaux et 56 pl. gavées, fig. noires (de 140 genera). 8°. Paris, Levrault. Also: “Avec les fig. noires et color. Dohrn, Anton. 69. Untersuchungen iiber Bau und Entwickelung der Arthropoden. 3. Die Scha- lendrtise und die embryonale Entwickelung der Daphniden. (1 pl.) Jen. Zeitschr. d. Naturwiss. Bd. 5, Heft 2, pp. 277-292. Du Plessis-Gourret, G. ’85, Essaisur la fauune profonde des lacs de la Suisse. ; (Mem. cor. par la Soc. Helvét. d. Sc. Nat.) (63 pp.) Neue Denksdhi. d. allg. Schweiz. Gesellsch. f. d. ges. Naturwiss. Bd. 29, Abth. 2. Also separate: Bale, 1885. 4°. Elymann. 87. Beitrag zur Systematik der europdischen Daphniden. Ber. Naturforsch. Gesellsch. Freiburg in Breisgau. Bd. 2, pp. 67-148. ENTOMOSTRACA OF MINNESOTA. 17 Euren, A. ’°62. Om markliga Crustaceer af ordningen cladocera, funna i Dalarne. Ofvers. K. Vetensk. Akad. Forhandl. 18 Arg. 1861. Pp. 115-118. Ferussac, Daudebart de. 706. Mémoire sur deux nouvelles espéces d’ Entomostracés et d’ Hydrachnés, Paris, Ann. Mus. Hist. Nat. VII, pp. 212-218. Fischer, Seb. 749, Abhandlungen tiber eine neue Daphnienart, Daphnia aurita und liber die Daphnia laticornis Jurine mit Zeichnungen nach der Natur begleitet. (2 pl.) Bull. Soc. Imp. Nat. Moscou. T. 22, pt. 2, pp. 39-51. ’51, Bemerkungen tiber einige weniger genau gekannte Daphnienarten. (1 pl.) Ibid. T. 24, pt. 2, pp. 96-108. ’51!, Branchiopoden und Entomostraceen. In A. Th. v. Middendorffs Reise in den daussersten Norden und Osten Sibiriens wahrend der Jahre 1843 und 1844, .. . (etc.). Bd. 2, Thi. 1. Wirbellose Thiere: Annulaten. Echinodermen. In- secten. Krebse. Mollusken. Parasiten. (By various authors.) 32 pl., 516 pp. 512, Beitraige zur Kenntniss der in der Umgegend von St. Petersburg sich finden- den Cyclopiden. (2 pl.) Bull. Soc. Imp. Nat. Moscou. T. 24, pt. 2, pp. 409-438. (See 753.) 52. Ueber die in der Umgebung von St. Petersburg vorkommenden Crustaceen aus der Ordnung der Branchiopoden und. Entomostraceen. (10 pl.) Mem. pres. savants Acad. St. Petersbg. T. 6, 1851, pp. 159-198. ’63. (Title and reference asin ’51?. T. 26, 1853, pt. 1, pp. 74-100.) (2 pl.) 54, Ergadnzungen, Berichtigungen und Fortsetzung zu der Abhandlung ueber die in der Umgebung von St. Petersburg vorkommenden Crustaceen. (3 pl.) Mem. pres. savants Acad. St. Petersbg. T. 7, pp. 1-14. Also separate: St. Petersburg, 1850. 4°. 14 pp. "541, Abhandlung tiber das Genus Cypris und dessen in der Umgebung von St. Petersburg und Reval vorkommende Arten. (11 pl.) Ibid. T. 7, pp. 127-167. Also separate: St. Petersburg, 1851. 4°. 39 pp. (11 pl.) 9 54°, Abhandlungen tiber einige neue oder nicht genau gekannte Arten von Daph- piden und Lynceiden als Beitrag zur Fauna Russlands. (1 pl.) Bull. Soc. Imp. Nat. Moscou. T. 27, pt. 1, pp. 423-434. 60. Beitrage zur Kenntniss der Entomostraceen. (3 pl.) Abhandlgn. d. k. bayer. Akad. d. Wiss. II. Cl. Bd. 8, Abth. 3, pp. 647-682. Also separate: Munchen, 1860. 4°. 38 pp. Forbes, S.A. 76, List of Illinois Crustacea. Bull. HJ. Mus. Nat. Hist. No. 1, pp. 3-25. ’82. On some Entomostraca of Lake Michigan and adjacent waters. (2 pl.) Amer. Naturalist. Vol. 16, July, pp. 537-542; Aug., pp. 640-649. 91. Onsome Lake Superior Entomostraca. (4 pl.) Rep. U. S. Com. Fish and Fisheries for 1887. Pp. 701-718. na nee ss Tes ™ 18 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. °93. A preliminary report on the aquatic invertebrate fauna of the Yellowstone National Park, Wyoming, and of the I‘lathead Region of Montana. Bull. U. S. Fish Commission for 1891. Forel, F. A. 74, Faune profonde du lac Léman. Verhandl. d. Schweiz. naturf. Gesellsch. 56. Vers. Schaffhausen. 1873. Pp. 136-153. 75. Id. (Deuxieme Discours.) Ibid. 57. Vers. Chun. 1874. pp. 129-142. Extr. par P, Fischer in: Journ. d. Zool. T. 3, 1874, pp. 352-354. 76, Notice sur l’histoire naturelle du lac Léman. 78. Faunistische Studien in den Siisswasser-Seen der Schweiz. Zeitsch. f. wiss. Zool. Bd. 30, Suppl. Heft 2, pp. 383-391. ’80. Les faunes lacustres de la région subalpine. Assoc. franc. pour |’ avancem. d. sc. C. R. de la 8. Sess. 1879. Pp. 744-748. *82,. Die pelagische Fauna der Stisswasserseen. Biol. Centralblatt. Bd. 2, No. 10, pp. 299-305. 185, La faune profonde de lacs Suisses. Neue Denkschr. d. allg. Schweiz. Gesellsch. f. d. ges. Naturwiss. Bd. 29, Abh. 2. 234 pp. Also separate: Bale, 1885. 4°. Forest, H. E. 79. Oo the Anatomy of Leptodora hyalina. (2 pl.) Journ. Roy. Microse. Soc. Vol. 2, pp. 825-834. Fric, Anton. 67, Korysi zeme ceske Ziva Casopis prirodnicky. XIV. (N.F.II.) Pp. 1; 102; 171; 241. 72, Ueber d. Faunad. BOhmerwaldseen. Sitzber. d. bohm. Gesellsch. d. Wiss. Jahrg. 1871, Juli-Dec. Pp. 3-12. ‘721, Die Krustenthiere Boehmens. (100 text-figures.) 3 Archiv. f. d. naturwiss. Landesdurchforsch. v. Boehmen. Bd. 2, Abth. 4, pp. 201-271. 73, Ueber die Crustaceenfauna der Witlingauer Teiche und iiber weitere Unter- such. d. Bohmerwaldseen. Sitzungsber. d. k. bohm. Gesellsch. d. Wiss. Prag. Jahrg. 1873, pp. 33-47. °731, Zviréna jezer Sumavskyeh. Vesmir. II. p. 247. °74, Ozvirene rybniku trebouskych. Vesmir. III. Fritsch, Anton. ’°66. Ueber das Vorkommen von Apus und Branchipus in BOhmen. Verhandl. d. Kais.-Konigl. zoolog.-botan. Gesell. in Wien. XVI, pp. 557-5 2 Geer, Charles de. 1778. Memoires pour servir 4 1’ Histoire des Insectes. 7 vols. Stockholm, 1752- 78. (Crustacea in Vol. VII, pp. 950, pl. 49.) 1783. Above under title: Abhandlungen zur Geschichte der Insekten, aus dem Franz. ubersetzt mit Anmerkungen. Herausgegeben von Joh. Aug. Ephr. Goeze. Ntirnberg, 1778-1783. (Vol. VII, 1783.) ENTOMOSTRACA OF MINNESOTA. 19 ’ Gegenbaur, C. 58. Mittheilungen iiber die Organisation von Phyllosoma und Sapphirina. (2 pl.) Miiller’s Archiv. f. Anat. u. Physiol. 1858, pp. 43-81. Gerstacker, A. "79, Die Klassen und Ordnungen der Arthropoden wissenschaftlich dargestellt in Wort und Bild. Bronn’s Klassen u. Ord. d. Thier-Reichs. Ftinfter Band. Gliederfiissler (Arthro- poda). 1866-1879. [Copepoda, pp. 590-806, pl. VII-XV. ] Giesbrecht, W. 81. Vorlaufige Mittheilung aus einer Arbeit tiber die freilebenden Copepoden des Kieler Hafens. Zool. Anz. Jaurg. 4, No. 83 (May 16), pp. 254-258. ’81'. Die freilebenden Copepoden der Kieler Fohrde. (12 pl.) 4 Ber. d. Comm. z. wiss. Unters. d. deutsch. Meere in Kiel. Abth. I, pp. 85-168. - Gissler, Charles F. 72. Contributions to the Fauna of the New York Croton Water. Microscopical Observations during the years 1870-71. New York. 81. Variations in a Copepod Crustacean. (14 text-figures.) American Naturalist. Vol. 15, Sept., pp. 689-698. Goodsir, H. D. ‘45, Oa several new species of Crustaceans allied to Saphirina. (1 pl.) Ann. and Mag. Nat. Hist. Vol. 16, pp. 325-327. Grobben, Carl. °79, Die Entwickelungsgeschichte der Moina rectirostris. Zugleich ein Beitrag zur Kenntniss der Anatomie der Phyllopoden. (7 pl.) Arbeiten a. d. zoolog. Inst. d. Universitat Wien. T. 2, Heft 2, pp. 203-268. Also separate: Wien, 1879. 81. Die Entwicklungsgeschichte von Cetochilus septentrionalis Goodsir. (4 pl. and 2 text-fizures. ) Arbeiten a. d. zoolog. Inst. d. Universitat Wien. T.3, Heft 3, pp. 243-282. Also separate: Wien, 1881. Grube, A. E. ‘53 Bemerkungen tiber die Phyllopoden, nebst einer Uebersicht ihrer Gattungen und Arten. (4 pl.) Arch. f. Naturgesch. Jahrg. 19, Bd. 1, pp. 71-172. Also separate: Berlin, 1853. 8°. 108 pp. Gruber, A. "78. Ueber Zwei Stisswasser-Calaniden. (2 pl.) Promotionsschrift, Leipzig. 34 pp. Gruber, Aug., und Aug. Weisman. 80. Usher einige neue oder unvollkommen gekannte Daphniden. (2 pl.) Ber. ub. d. Verh. d. naturf. Gesellsch. Freiburg i. B. Bd. 7, pp. 50-116. Gruithuisen, Frz. v. Paula. ’28. Ueber die Daphnia sima und ihren Blut-Kreislauf. (1 pl.) Nova Acta Acad. Leop. Carol. Nat. Cur. Tom. 14, pt. 1, pp. 397-406. 2 20 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. Guerne, Jules de. ’86, Description du Centropages Grimaldii, Copépode nouveau du golfe de Fin- lande. Bull. Soc. Zool. France. T. 11, No. 1-3, pp. 276-285. Guerne, Jules de, et J. Richard. 88. Sur la distribution géographique du genre Diaptomus. Compt. Rend. Acad. Sc. Paris. T. 107, No. 1, pp. 47-50. Translated in Ann. and Mag. Nat. Hist. Ser. 6, Vol. 2, pp. 177-179. 7881, Diagnoses de deux Diaptomus nouveaux d’ Algérie. Bull. Soe. Zool. France. T. 13, No. 6, pp. 160-162. 789, Note sur les Entomostracés d’eau douce recueillis par M. Charles Rabot dans la province de Nordland, Norvége septentrionale. Ibid. T. 14, No. 1, pp. 27-31. 1891, Revision des Calanides d’eau douce. (5 pl.) Mem. de la Soc. Zool. de France. T. 2, pt. 1, pp. 53-181. 1892, Sur la faune des eaux douces du Greenland. Bull. Soc. Entom. Fr. (Compt. Rend. Ac. Sc. Paris. T. 108, No. 12, pp. 630- 632.) 191, Sur quelques entomostracés d’eau douce de Madagascar. Bull. Soc. Zool. France. T. 16, No. 8, pp. 223-224. 192. Sur la faune des eaux douces d’Islande. (Voyage de M. Charles Rabot en Islande. ) Bull. Soc. Entom. Fr. 8 fevrier, 1892. (Bull. Soc. Zool. France. T. 17, No. 3, pp. 75-80.) Also: Compt. Rend. Acad. Sc. Paris. T. 114, No. 6, pp. 310-313. Gunner. 1765. Skrifter som udi det Kjobenharnske Selskab. (Acta Harniae. ) Haeckle, Ernst. ’°63. Beitrage zur Kenntniss der Corycaeiden. (3 pl.) Jen. Zeitschr. f. Naturwiss. Bd. 1, 1864, pp. 61-112. Haldeman, S$. S. ’43. Daphnia abrupta and Cypris scabra n. sp. Proc. Acad. Nat. Sc. Philad. Vol. 1, p. 184. ’431. Daphnia reticulata n. sp. Ibid. Vol. 1, p. 196. Haller, G. "79. Vorliufige Diagnosen einiger Peltidien aus Messina. Zool. Anzeiger. Jahrg. 2, No. 25 (7. April), pp. 178-180. ’80. Beschreibung einiger neuer Peltidien. (2 pl.) Archiv. f. Naturgesch. Jahrg. 46, Bd. 1, pp. 55-71. Hartog, M. M. °84. The Morphology of Cyclops and the relations of the Copepoda. Trans. Linn. Soc. Lond. (2.) Zool. V. [Abstractin: Zool. Anzeiger. Jahrg. 8, No. 195 (18. Mai, 1885), pp. 301-302. ] Heller, Camil. °70. Untersuchungen tiber die Crustaceen Tirols. Nat. Med. Berichte. Innsbruck. I, pp. 67-96. . ENTOMOSTRACA OF MINNESOTA. 21 Hellich, B. 74. Ueber die Cladocerenfauna BOhmens. Sitzungsber. d. k. k. bOhm. Gesellsch. der Wiss. Prag. Jahrg. 1874, pp. 205-220. "77. Die Cladoceren BOhmens. (Wood cuts.) Arch. f. d. naturw. Landesdurchforschung v. Bohmen. Bd. 2, Abth. 4, Heft 2, p. 131. Also separate: Prag, 1877. 8°. Pp. IV, 131. Herrick, C. L. "79. Microscopic Entomostraca .(21 pl.) The Geol. and Nat. Hist. Survey of Minnesota. The Seventh Annual Report, for the year 1878. (Appendix.B.) Pp. 81-123. *82. Papers on the Crustacea of the Fresh Waters of Minnesota. (11 pl., 7 wd, cts.) (I. Cyclopide of Minnesota, with notes on other Copepoda. II. Notes on some Minnesota Cladocera. III. On Notodromas and Cambarus. ) Ibid. The Tenth Annual Report, for the year 1881. Pp. 219-254. 183. Heterogenetic development in Diaptomus. (3 pl.) Amer. Naturalist. Vol. 17, April, pp. 381-389 (2 pl.); May, pp. 499-505. (1 pl.) ’*84. A final report on the Crustacea of Minnesota included in the orders Cladocera and Copepoda. The Geol. and Nat. Hist. Survey of Minnesota. The Twelfth Annual Report, for the year 1883. V. Crustacea. 192 pp. (30 pl.) ’87. Contribution to the fauna of the Gulf of Mexico and the South. (List of Fresh-water and Marine Crustacea of Alabama, with descriptions of the New Species and Synoptical Keys for Identification.) (7 pl.) Mem. Denison Scient. Assoc. Vol. 1, No.1. 52 pp. Hesse, Eugene. 764. Observation sur des Crustacés rares ou nouveaux des cdtes de France Troi- siéme article. (Crustacésparasites dans |’ intérior des Ascidies. 2 pl.) Ann. d. Science. Nat.-Zool. Ser. 5, T. 1, pp. 333-358. ’°68. Mémoire sur les Pranizes et les Ancées et sur les Moyens curieux 4 |’ Aide desquels certains Crustacés Parasites assurent la Conservation de leur Espéce. Mém. prés. par divers Savants 4 I’ Inst. Impér. de France. XVIII. (Mém. Savants Etrang. Paris. XVIII, pp. 231-302. Also: Ann. and Mag. Nat. Hist. Vol. 14, 1864, pp. 405-517.) "79. Description des Crustacés rares ou nouveaux des Cétes de France décrits et peints sur des Individus vivants. 29° Art. Description de dix nouveaux Crus- tacés, dont sept appartiennent du Genre Cycnus de Kroyer et trois au Genre Kroyeria de Van Beneden, tous décrits et dessinés sur des Individus vivants. (Avec 2 pl.) Ann. Se. Nat. Zool. Ser. 6, T. 8, No. 4, Art. 11. 34 pp. Heyden, C. v. 762. Meyers Paleontographica. X. Hoek, P. P. C. 76. De Vrijlevende Zoetwater-Copepoden/der Nederlandsche Fauna. (5 pl.) Tijdschr. d. Nederland. Dierkund. Vereenig. III. Deel, 1878. 36 pp. 22 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. 77. Zar Entwickelungsgeschichte der Entomostraken. II. Zur Embryologie der freilebenden Copepoden. (2 pl.) Niederland. Archiv. f. Zool. Bd. 4, Heft 1, pp. 55-74. Hogan, Rev. A. R. ’°62. Oa Daphnia Scheefferi. Rep. 31st Meet. Brit. Assoc. Advance. Sc. in 1861. Notes and Abstracts, p. 146. Hudendorff, A. "76. Beitrag zur Kenntniss der Stisswasser-Cladoceren Russlands. (1 pl.) Bull. Soc. Impér. des Nat. de Moscou. T. 50, pp. 26-61. Imhof, Othmar Emil. ’*83. Die pelagische Fauna und die Tiefseefauna der zwei Savoyerseen. Lac du Bourget und Lac d’ Annecy. Zool. Anzeiger. Jahrg. 6, No. 155 (10 Dec.), pp. 655-657. "84. Weitere Mittheilung iiber die pelagische Fauna der Stisswasserbecken. Ibid. Jahrg. 7, No. 169 (9 Juni), pp. 321-327. *841. Resultate meiner Studien iiber die pelagische Fauna kleinerer und grOsserer Stisswasserbecken der Schweiz. (1 pl.) Zeitschr. f. wiss. Zool. Bd. 40, Heft 1, pp. 154-178. Alsc separate: Inaug. Diss. Ziirich. °85. Faunistische Studien in achtzehn kleineren und grésseren Osterreichischen Stisswasserbecken. Sitzber. d. k. Akad. d. Wiss. in Wien. Math. nat. cl. Bd. 91, Abth. 1, pp. 203- 226. °85!. Ueber die ‘“‘blassen Kolben’’ an den vorderen Antennen der Siisswasser- Calaniden. Zool. Anzeig. Jahrg. 8, No. 197 (15. Jani), pp. 353-356. 85°. Pelagische Thiere aus Siisswasserbecken in Elsass-Lothringen. Ibid. No. 211 (14. Dec.), pp. 720-723. *88. Ueber das Calanidengenus Heterocope. Zool. Anzeiger. Jahrg. 11, No. 286 (20. Aug.), pp. 447-451. Joblot, Louis. 1754-55. Observations d’histoire naturelle, faites avec le microscope, sur un grand nombre d’insectes, et sur les animaleules qui se trouvent dans les liquers pré- parées, etc. . . Avecun grand nombre de figures. 2 Tom. 4a 2 pts. (Avec. 14, 15, et 24 pl.) 4° Paris, 1754-55. Joly, N. 40. Histoire d’un petit Crustacé (Artemia salina Leach), auquel ou a faussement attribué Ja Coloration en Rouge des Marais salants Méditerranéens, suivie de Recherches sur la Cause réelle de cette Coloration. (3 pl.) Ann. Sci. Nat.— Zool. 13, pp. 225-290. (Montpelier, 1840. 4°. 72 pp.) 83. Etudes complémentaires sur l’origine et le mode de formation de la glairine ou barégine dans les eaux thermales sulfurenses des Pyrénées. Memoires de 1’ Académie des Sc., etc., de Toulouse. ENTOMOSTRACA OF MINNESOTA. 23 Joseph, G. *82. Systematisches Verzeichnis der in den Tropfstein-Grotten von Krain ein- heimisher Arthropoden (nebst Diagnosen der vom Verfasser entdekten und bisher noch nicht beschriebenen Arten. ) Berlin Entomolog. Zeitschr. Bd. 26, Heft 1, pp. 1-50. Jurinac, A. E. 87. Prilog fauni zapodne Slavonije. Glasnik hrvatskoga naravoslovoga drzutra. II. Jurine, Louis. 01. Sur le Monocle puce (Daphnia pulex). Bull. des Se. par la Soc. philom. de Paris. Tom. 3, An. 9, pp. 33-34. 20. Histoire des Monocles qui se trouvent aux environs de Genéve. Avec 22 pl. color. 4°. Genéve. (King, (Capt.) Philip Parker. ’54-'59, The references available assign the title given by Herrick’under R. L. King to P. P. King. ] King, R. L. 52-54. On some species of Daphnidsx found in New South Wales. Roy. Soc. Papers Van Diemen’s Land. II, 1852-54, pp. 243-253. 65. On Australian Entomostracans. Papers and Proceedings of the Roy. Soe. of Van Diemen’s Land. III. (II, 1852- 54, pp. 253-262; III, 1855-59, pp. 56-75. Title and references were found only under ‘‘Capt. Philip Parker King.’’) Klunzinger. 64. Einiges zur Anatomie der Daphnien, nebst kurzen Bemerkungen iiber die Stisswasserfauna der Umgegend Cairo’s. (1 pl.) Zeitschr. f. wiss. Zool. Bd. 14, Heft 2, pp. 165-173. Koch, C. L. °35-'41. Deutschlands Crustaceen, Myriapoden und Arachniden. Ein Beitrag zur deutschen Fauna. Heransgeg. von Herrich-Schaffer. Regensburg. (Nu- merous plates and text figures. ) Koelbel, C. 85. Carcinologisches. (3 pl.) Sitzber. d. k. k. Akad. Wiss. Wien. Bd. 90, Abth. 1, pp. 312-323. Also separate. Kortchaguine, A. N. "73. Uber Diaptomus amblyodon. (See Marenzeller. ) Verhandl. Zool. bot. Gesellsch. Wien. Vol. 23. *87. Faune des environs de Moscou. I. Crustacés. Bull. de la Soc. des Amis des se. nat. de Moscou, 52. Kroyer, Henr. 45-49. Karcinologiske Bidrag. . Nat. Tidskr. Ny Raekke 2 det Binds 5. Haefte. (4 pl.) (Kroyer naturhist. Tidskr. N. R. Bd. 1, 1345, pp. 283-345 and 453-688; Bd. 2, 1849, pp. 1-211) 366-446, 527-6(19.) 24 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. Kurz, Wilh. "74. Dodekas neuer Cladoceren nebst einer kurzen Uebersicht der Cladoceren- fauna BOhmens. (3 pl.) Sitzungsber. d. k. k. Akad. d. Wissenschaft. in Wien. Math.-naturw. Classe. Bd. 68. (Ibid. Bd. 70, Abth. 1, 1875, pp. 7-88. Also separate: Wien, 1876. 8°. 82 pp. 75. Ueber androgyne Missbildung bei Cladoceren. (1 pl.) Ibid. Bd. 69, Abth. 1, 1874, pp. 40-46. Also separate: Wien, 1875. 8°. 7 pp. "78. Ueber limicole Cladoceren. (1 pl.) Zeitschr. f. wiss. Zool. Bd. 30, Suppl. Heft 2, pp. 392-410. Lamarck, J. B. P. Ant. de Monnet. 15-22. Histoire naturelle des animaux sons vertébres, présentant les caractéres généraux et particuliers de ces animaux, leur distribution, leurs classes, leurs familles, leurs genres et la citation synonymique des principales espéces qui s’y rapportent. (1° édit. 7vols. 2° édit. 11 vols. 1835-45. Paris.) Landenburger, R. °84. Zur Fauna des Mansfelder Sees. Zool. Anzeiger. Jahrg. 7, No. 168 (26. Mai), pp. 299-302. Lankester, E. Ray. ’°82. On new British Cladocera discovered by Mr. Conrad Beck in Grasmere Lake, Westmoreland. Ann. Mag. Nat. Hist. Vol. 9, p. 53. Latreille, Pierre Andre. 1792-1805. Histoire naturelle, générale et particuliére, des crustacés et des In- sectes. (Ouvrage faisant suite aux oeuvres de Leclerc de Buffon et partie de cours complet d’hist. naturelle redigé par C. S. Sonini. 14 Vols. Avec 374 pl. 8°”. -Paris:) Leach. 19. Entomostraca. Dict. Sc. Nat. XIV. 23. Crustaceology. Edinburgh Encyclopedia. Ledermuller. 1763. Mikroskopische Gemiiths-und Augen-Ergotzung. Bestehend in Ein Hun- dert nach der Natur gezeichneten u. mit Farben erleuchteten Kpfrtaf., sammt deren Erklarung. Niirnberg. 1761. (Num. plates.) Lenz, Heinrich. ’82. Die wirbellosen Thiere Travemtinder Bucht. 4. Bericht der Comm. z. wiss. Unters. d. Deutschen Meere. Abth. 1, pp. 169- 180. Lereboullet, (Auguste). 50. Observations sur le coeur et (sur) la circulation dans (la Limnadia Herrmanni et dans) les Daphnies. Mém. Soc. Mus. d’hist. nat. Strasbourg. T. IV, Livr. 1, pp. 208-210. ENTOMOSTRACA OF MINNESOTA. 25 Leuckart, Rudolph. 59. Carcinologisches. (2 pl.) Arch. f. Naturgesch. Jahrg. 25, Bd. 1, pp. 232- 266. (—Einige Bemerkungen tiber Sacculina Thomps. (Pachybdella Dies., Peltogaster Rathke). (Fig.) pp. 232-241. —Ueber die Gesichtswerkzeuge der Copepoden. pp. 247-262. —Ueber das Vorkommen eines saugnapfartigen Haftapparates bei den Daphniden und verwandten Krehsen. (Figs.) pp. 262-265.) Leydig, Franz. 50. Ueber Argulus foliaceus. Ein Beitrag zur Anatomie, Histologie und Ent- wickelungsgeschichte dieses Thieres. (2 pl.) Zeitschr. f. wiss. Zool. Bd. 2, pp. 323-349. 51. Ueber Artemia salina und Branchipus stagnalis. Beitrag zur anatomischen Kenntniss dieser Thiere. (1 pl ) Ibid. Bd. 3. pp. 280-307. *59. Bemerkungen tiber den Bau der Cyclopiden. (1 pl.) Archiy. fiir Naturgesch. Jahrg. 25, pp. 194-207. ’*60. Naturgeschichte der Daphniden (Crustacea Cladocera). Mit 100 Kupferta- feln. 4°. Pp. IV, 252. Ttibingen. Lievin. ’*48. Die Branchiopoden der Danziger Gegend. Ein Beitrag zur Fauna der Pro- vinz Preussen. Neueste Schriften der naturf. Gessellsch. in Danzig. Bd. 4, Heft 2. Lilljeborg, Wilh. 53. Om den inom Skane forekommande Crustaceer af ordningarne Cladocera, Os- tracoda och Copepoda. Also De Crustaceis ex ordinibus tribus: Cladocera, Os- trocoda et Copepoda in Scania occurentibus. (27 pl.) Akademisk Afhandling. 2 sectiones. Lund, 1853. 8°. Pp. XVI, 222. ’61. + Beskrifning 6fver tvenne markliga Crustaceer af Ordningen Cladocera. (2 pl.) Ofvers kOngl. Vetensk. Akad. Forhandl. 17. Arg. 1860, pp. 265-271. (Transl. in: Ann. and Mag. Nat. Hist. Ser. 3, Vol. 9, 1862, pp. 132-136.) ’63 = Beskrifning Ofver tva arter Crustaceer af ordningarna Ostracoda och Copepo- da. (2 pl:) Ibid. 19 Arg. 1862, pp. 391-398. "76. De under Svenska velenskapliga expeditionen till Spetsbergen 1872-73 der- stades samlade Hafs-Entomostraceer. Ibid. 32 Arg. 1875. No. 4, pp. 3-12. ° 8 *87. Contributions to the Natural History of the Commander Islands. No. 9. On the Entomostraca collected by Mr. Leonhard Stejeneger, on Bering Island, 1882-83. Proceed. U. S. Nat. Mus. Vol. 10, 1887, p. 153. 88. Description de deux espéces nouvelles de Diaptomus du Nord de 1’Europe. Bull. Soc. Zool. France. T. 13, No. 6, pp. 156-158. Lindstrom, G. _ 55. Bidrag till Kannedomen om Oestersjéns Invertebrat-Fauna. Oefversigt K. Vet. Ak. Forhandl. Stockholm. Pp. 49-73. 26 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. Loven, S. L. 35. Evadne Nordmanni ett hittills okandt Entomostracon. (2 pl.) K. Vet. Akad. Handl. Stockholm. Pp. 1-29. (Also in Arch. f. Naturgesch. 1838, IV, pp. 143-166; and |’ Institut III, 1835, p. 262. 45. Fyrauya arter af SOtvattens-Crustaceer frau Sédra Afrika. (4 pl.) Kong. Vet. Akad. Handl. Stockholm. 1845. Pp. 427-441. "47. Om afrikanska sOtvattens Crustaceer. Ofversigt. K. Vetensk. Akad. Férhandl. Stockholm. 1846. Pp. 57-58. Lubbock, John. 53. Description of a new genus of Calanidae (Labidocera). (1 pl.) Ann. and Mag. Nat. Hist. Ser. 2, Vol. 11, pp. 25-29. 631. On the Freshwater Entomostraca of South America. (1 pl.) Proc. Roy. Soc. of Van Diemensland. (Trans. Entom. Soc. London: New Ser. Vol. 3, 1854, pp. 232-240.) *54. Onsome arctic species of Calanidae. (1 pl.) Ann. and Mag. Nat. Hist. Ser. 2, Vol. 14, pp. 125-129. °76. On some Entomostraca collected by Dr. Sutherland in the Atlantic Ocean. (11 pl.) Trans. Entom. Soc. London. N.S. Vol. 4, prt. 1 and 2, pp. 8-37. 57. An account of the two methods of reproduction in Daphnia and of the struc- ture of the Ephippium. (2 pl.) Philos. Trans. Pp. 79-100. 59. Descriptions of eight new species of Entomostraca found at Weymouth. (2 pl.) Ann. and Mag. Nat. Hist. Ser. 2, Vol. 20, pp. 401-410. ’°60. On some Oceanic Entomostraca collected by Captain Toynbee. (1 pl.) Trans. Linn. Soc. London. Vol. 23, pt. 1, pp. 173-191. ’°63. Notes on some new or little-known species of fresh water entomostraca. (1 pl.) Ibid. Vol. 24, pt. 2, pp. 197-210. Lucas, Hippolyte. ’49. Exploration scientifique de l’Algérie pendant les années 1840, 1841, 1842, publiée par ordre du gouvernement, etc. 16 vols. 1846-58. Animaux artic- ulés par Lucas. Livr. 1-33. Lund, L. "70-71. Bidrag til Cladocerernes*morphologi og systematik. (5 pl.) Naturhist. Tidsskrift. Raek 3, Bd. 7, pp. 129-174. Lutz, Adolf. 78. Beobachtungen tiber die Cladoceren in der Umgegend von Leipzig. Sitzungsber. d. naturfor. Gesellsch. Leipzig. Jahrg. 5, pp. 36-41. "79. Untersuchungen ueber die Cladoceren der Umgebung von Bern. Mitth. naturfor. Gesellsch. Bern. 1878. Pp. 38-54. ‘ Marcusen, Johann. °67. Zur Fauna des schwarzen Meeres. Archiv. f. Naturgesch. Jahrg. 33, pp. 357-363. ENTOMOSTRACA OF MINNESOTA. ‘ 27 Marenzeller, Emil von. "73. Ueber Diaptomus amblyodon. n. sp. (Fig.) Verhandlgn. k. k. zool.-bot. Gesellsch. Wien. Bd. 23, pp. 593-596. Marsh, C. Dwight. 192. On the deep water crustacea of Green Lake. Trans. Wis. Acad. Sc. Arts and Letters. Vol. 8, 1888-91, pp. 211-213. "93. On the Cyclopide and Calanide of Central Wisconsin. (4 pl.) Ibid. Vol. 9, Part 1, 1892-93, pp. 189-224. "94. On Two New Species of Diaptomus. (1 pl.) [Mississippiensis and birgei. ] Ibid. Vol. 10, July, 1894. Matile, Paul. ’90. Die Cladoceren der Umgegend von Moskau. (3 pl.) Bull. Soc. Imp. Nat. Moscou, 1890. JI, pp. 104-169. Metschnikow, E. *84. Ueber eine Sprosspilzkrankheit der Daphnien. Virchow. Arch. f. path. Anatomie. Bd. 96. Metzger, A. "71. Die wirbellosen Meeresthiere der ostfriesischen{K liste. Crustaceen. Jahresber. d. Nat. Gesellsch. zu Hannover. 20, pp. 22-26. Milne-Edwards, H. 34-40. Histoire naturelle des Crustacés (comprenant l’anatomie, la physiologie et la classification deces animaux. Avec42pl. 3 Vols. 8°. Paris, 1834, ’37, ’40.) Moebius, Karl. "73. Die wirbellosen Thiere der Ostsee. (Expedition zur Untersuchung der Ostsee. 1871.) Faunistische Untersuchungen. Jabresb. d. Comm. zur Unters. d. deutsch. Meere. 1, 1873, pp. 97-144; 7 bis 11, 1884, p. 61 bis-70 bis. "731. Die auf der Fahrt nach Arendal gefangenen Thiere, Crustacea Ebenda. Jahresb. d. Comm. zur Unters. d. deutsch. Meere. "75. Copepoda and Cladocera. (In: Expedition zur Untersuchung der Nordsee. 1872. Zoologische Ergebnisse. IX.) Jahresb. d. Comm. zur wiss. Unters. d. deutsch. Meere. 2 and 3, 1875, pp. 269- 276. Moniez, R. 87. Liste des Copépodes, Ostracodes, Cladocéres, et de quelques autres Crustacés recueillis a Lille en 1886. Bull. de la Soc. zool. de France. T. 12, pts. 2-6, pp. 508-518. ’*87:. Note sur des Ostracodes, Cladocéres et Hydrachnides observés en Norman- die, et description de quelques espéces nouvelles. Bull. dela Soe. d’études se. de Paris. 877. Entomostracés et Hydrachnides recueillis par M. Dollfus. Feuille des jeuues naturalistes. Moniez, R., et Th. Barrois. 88. Matériaux pourservir 4 |’étude de la Faune des eaux douces des AGores. IV. Crustacés. [Copepodes par Barrois; Ostracodes, Cladocéres, Branchiopodes par Moniez.] Lille, 1888. 8°. 20 pp. 28 : GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. Mueller, P. E. ’68, Danmarks Cladocera. (Med.6 Tab. og 1.Traesnit.) Naturhist. Tidsskrift. 3. Raek. Bd. 5, 1868-69, pp. 53-240. 69. Efterskrift til Danmarks Cladocera. Ibid. Pp. 355-356. 691, Bidrag til Cladocerernes Forplantnings-historie. (Med 1 Tab.) Naturhistorisk Tidsskr. 3 Raek. Bd. 5, 1868-’69. Pp. 295-354. Also: Forhandl. Skand. Naturforsk. 10 Mode. Christiania. (1868.) 1869. Pp. 530-540. , Muller, Otto Friedrich. 1775, Entromostraca, seu insecta testacea, que in aquis Dani et Norvegiz reperit, descripsit et iconibus illustravit. Cum tabb. aen. XXI. 4 maj. Lip- siz et Hafnize 1785. 1776. Zoologiz Danice prodromus, seu animalium Daniz et Norvegie indigen- arum characteres, nomina et synopyma imprimis popularium. 8 maj. Hafnie. (274 pp.) 1785, Von dem mopsnasigen Zackenfloh (Daphnia resima). Schrift. d. Berlin. Gesellsch. Nat. Fr. Bd. 6, pp. 185-192. 1788-1806. Zoologia Danica, seu animalium Daniz et Norvegie rariorum ac minus notorum descriptiones et historia; ad formam tabularum denuo edid. frater auctoris. IV Voll. Cum CLX tabb. Fol. Hafnie et Lipsiz (1779-84) 1788-1806. (German and Latin text.) Muller, Wilhelm. : 80. Beitrag zur Kenntniss der Fortpflanzung und der Geschlechtsverhaltnisse der Ostracoden nebst Beschreibung einer neuen Species der Gattung Cypris. (bicolor. ) Zeitschr. f. d. gesam. Naturwiss. Jahrg. 53 (3. F. Bd. 6.), pp. 221-246. Also separate: Inaug. Dissert. Greifswald, 1880, 8°. 28 pp. Nicolet, Hercule. ’49, Crustaceos y Aracnidos. In: Claud. Gay’s Historia fisica y politica de @hiley.2..0-. auspicies del supremo gobierno. Paris, 1814-54. 8° (Atlas in Fol.) Zoologia. T. III. 547 pp. Nordman, Alexander von. 32. Zweites Heft in: Mikrographische Beitrage zur Naturgeschichte der wirbel- losen Thiere. 2 Hefte. 20 Kupfrtaf. 4°. Berlin. 64, Neue Beitrage zur Kenntniss parasitischer Copepoden. Erster Beitrag. (4 pl.) Bull. Soc. Impér. des Nat. Moscow. T. 37, P. 2, pp. 461-520. Nordquist, Ose. 86. Bidrag till Kannedomen om Crustacéfauna i nagra af mellersta Finlands sjOar. Acta Societatis pro fauna et flora fennica. T. 3, No.2. 26 pp. Helsingfors, 1886. 87. Bidrag till kinnedomen om Ladoga sjés crustac¢éfauna. Meddel. af Soc, pro Fauna et Flora fennica. Heft 14, pp. 116-138. °88. Die Calaniden Finlands. (Abdr. aus: Bidrag till Kannedom af Finlands Natur och Folk. Heft 47.) Helsingfors, Druck d. Finnl. Litter. Ges. 1888. 8°, 86 pp. 10 pl. ENTOMOSTRACA OF MINNESOTA. 29 Norman, Rev. Alfred Merle. 63. On Acantholeberis Lilljeb., a genus of Entomostraca new to Great Britain. (1 pl.) Ann. Mag. Nat. Hist. Ser. 3, Vol. II, pp. 409-415. 67. Report of the Committee appointed for the purpose of Exploring the Coast of the Hebrides by means of the Dredge. Part II. On the Crustacea, Echinoder- mata, Polyzoa, Actinozoa, and Hydrozoa. Rep. 36th Meet. Brit. Assoc. Advance. Sc. in 1866. Pp. 193-206. ’68. Shetland Final Dredging Report. Part II. On the Crustacea, Tunicata, Polyzoa, Echinodermata, Actinozoa, Hydrozoa; and Porifera. Rep. 38th Meet. Brit. Assoc. Advance. Sc. in 1868. Pp. 247-336, and Addenda, pp. 341, 342. "76, Crustacea, Tunicata, Polyzoa, Echinodermata, Actinozoa, Foraminifera, Poly- cystina, and Spangida. [From the cruise of the Valorus, 1875. ] Roy. Soc. Proc. 25, 1877, pp. 202-215. 77, Notes on the Oceanic Copepoda. Appendix of Capt. Nares’ forthcoming Arctic Voyage. Norman, A. M., and G. S, Brady. 67. A Monograph of the British Entomostraca belonging to the families Bosmin- idz, Macrothricide and Lynceidx. (6 pl.) Trans. Nat. Hist. Soc. Northumberland and Durham. Vol. 1, pt. 3, pp. 354-408. Also separate: London, 1867. Ouchakoff, Nicolas. 55, Pontie de Wacarino. Bull. Soc. Imper. Nat. Moscou. 28, 2, pp. 245-250. Pavesi, Pietro. 77, Intoras all ’esestenza della fauna pelagica o d’alto lago anche in Italia. Bull. Entomol. IX. "79, Nuova serie di ricerche della fauna pelagica nei laghi italiani. Rendiconti Roy. Instituto Lombardo. Ser. 2, Vol. 12. 10 pp. 791, Ulteriori studi sulla fauna pelagica dei laghi italiani. Ibid. Ser. 2, Vol. 12, Fasc. 16. 21 pp. (’81. Quarta serie di ricerche e studi sulla fauna pelagica dei laghi Italiani. (Sunto del autore. ) Bull. Soc. Ven.-Trent. 1881, pp. 68-70. ] [’83, Altra serie di ricerche e studi sulla fauna pelagica dei laghi italiani. Con 7 Tav. Atti Soc. Ven.-Trent. Sc. Nat. Vol. 8, Fasc. 2, pp. 340-403. Also separate: Padova, 1883. 8°.] Perty, M. 32. Uber den Kreislauf der Daphnien. _ Isis. Philippi, A. 39. Beobachtungen iber Copepoden des Mittelmeeres. Arch. f. Naturgesch. Nos. 40, 43, 44. 30 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. Plateau, Felix. ’70,. Recherches sur les Crustacés d’eau douce de Belgique. I. Genres Gammarus, Linceus et Cypris. (1 pl.) II and IIIf. Genres Daphnia, Bosmina, Polyphe- mus, Cyclopsina, Canthocamptus et Cyclops. (3 pl.) Mém. Couron. et Mém. d. sav. étrang. de Belgique. T. 34 (1867-70), 1870. 63 pp., and T. 35, 1870. 92 pp. Poggenpol, M. J. "74, List of the Copepoda, Cladocera and Ostracoda of the Environs of Moscow. (9 pp.) (In Russian. ) Poppe, S. A. ’80. Uber eine neue Art der Calaniden-Gattung Temora Baird [affinis]. (1 pl.) Abhandl. d. Naturwiss. Vereins z. Bremen. Bd. 7, Heft 1, pp. 55-60, 81. Uber einen neuen Harpacticiden (Tachidius littoralis.) (1 pl.) Ibid. Bd. 7, pp. 149-152. ’84. Bemerkungen zu R. Ladenburger’s: ‘‘Zur Fauna des Mansfelder Sees’’ {in No. 168 des Zool. Anzeigers. Zool. Anz. Jahrg. 7, No. 176 (Sept. 15), pp. 499-500. ’84!. Uber die von den Herren Dr. Arthur und Aurel Krause im nordlichen Stillen Ocean und Behringsmeer gesammelten freilebenden Copepoden. (5 pl ) Archiv. f. Naturgesch. Jahrg. 50, Bd. 1, pp. 281-304. 842, Ein neues Copepoden-Genus aus der Jade. [Huntemannia n. g., Jadensis n. sp. ] Abhandl. Naturwiss. Ver. zu Bremen. Bd. 9, Heft 1, pp. 57-58. 85, Die freilebenden Copepoden des Jadebusens. I. (4 pl.) Ibid. Bd. 9, Heft 2, pp. 167-206. 86. Ein neuer Diaptomus [Zacharize] ausdem Hirschberger Thal. (1 pl.) Zeitsch. f. wiss. Zool. Bd. 43, Heft 2, pp. 285-289. 87. Beschreibung einiger neuer Entomostraken aus norddeutschen Seen. (1 pl.) Ibid. Bd. 45, Heft 2 (April 13), pp. 278-281. ’88. Diagnoses de deux espéces nouvelles du genre Diaptomus Westwood. Bull. Soe. Zool. France. T. 13, No. 6, pp. 159-160. 89. Berichtigung zu Dr. O. E. Imhof’s Aufsatz. ‘‘ Fauna der Stisswasser-becken’”’ in No. 275 des Zool. Anz. 1888. P. 166. Zool. Anz. Jahrg. 12, No. 300 (Feb. 18), pp. 99-100. ’89'. Notizen zur Fauna der Siisswasser-becken des nordwestlichen Deutschland mit besonderer Beriicksichtigung der Crustaceen. (1 pl.) Abhdlgn. Naturwiss. Ver. Bremen. Bd. 10, Heft 3, pp. 517-551. 91. Ein neuer Diaptomus aus Brasilien. Diaptomus deitersi nov. sp. (3 text figs.) Zool. Anz. Jabrg. 14, No. 368 (Juli 20), pp. 248-250. Pouchet, G., et J. Guerne. ’81, 83. [Titles quite similar to those under Pavesi ’81 and ’83 were given here by the author. ] 85. Sur la faune pelagique de la mer Belgique et du golfe de Finlande. Compt. Rend. Acad. Sc. Paris. T. 100, No. 83, pp. 919-921. Also: Ann. Mag. Nat. Hist. Ser. 5, Vol. 15, June. Pp. 498-499. ENTOMOSTRACA OF MINNESOTA. 31 Pratz, E. 2. Uber einige im Grundwasser lebende Tiere. Beitrag zur Kenntniss der unterirdischen Crustaceen. St. Petersburg. Prostandrea, Nicolo. 33. Su di aleuni nuovi Crostacei di mare di Messina. Effemer. scient. e lett. per la Sicilia. (Palermo.) Vol. 6, pp. 3-14. Rathbun, R. 782. List of Marine Invertebrata, mainly from the New England Coast, distributed by the United States National Museum. Series II. and III. Proc. U.S. Nat. Mus. Vol. 4, 1881, pp 298-307. Redi, F. 1684. Osservazioni utorno agli animali viventi che si trovano regli animali viventi. Florenz. 1688. Animaletti aquatici. Napoli. Rehberg, Herm. 80.’ Zwei neue Crustaceen aus einem Brunnen auf Helgoland. Zool. Anzeiger. Jahrg. 3, No. 58 (Juni 21), pp. 301-303. ’*80!. Beitrag zur Kenntniss der freilebenden Stisswasser-Copepoden. (1 pl.) Abhandlgn. naturwiss. Ver. Bremen. Bd. 6, Heft 3, pp. 533-554. *80?. Weitere Bemerkungen tiber die freilebenden Stisswasser-Copepoden. (Iigs.) Ibid. Bd. 7, pp. 61-67. Reinhardt. 57, Fortegnelse over Groenlands Krebsdyr, Naturh. Bidrag til en Beskrivelse af Groenland. Richard, Jules. 87. Sur la faune pélagique de quelques lacs d’ Auvergne. Compt. Rend. Acad. Se. Paris. T. 105, No. 20, pp. 951-953. ’*87'. Liste des Cladocéres et des Copépodes d’eau douce observés en France. Bull. Soc. Zool. France. T. 12, pts. 3-4, pp. 156-164. *88. Entomostracés nouveaux ou peu connus. Ubidss D3: *881. Cladocéres et Copépodes non marins de la fauna de France. Rev. Scientif. Bourbonnais. Ann. 1, No. 3, pp. 57-70; No. 4, pp. 78-91. 90. Sur les Entomostracés et quelques autres animaux inférieures des lacs de Auvergne. (11 figs.) Revue des Sciences naturelles appliquées. 1890. No. 10. 11 pp. Also sepa- rate: Paris. 13890. 8°. ' 91. Recherches sur le systéme glandulaire et sur le systeme nerveux des Copé- podes libres d’eau douce, suivie d’une révision des éspéces de ce groupe qui vivent en France. (4 vl.) Ann. Se. Nat. Zool. Ser. 7, T. 12, No. 2, pp. 113-144; Nos. 3-4, pp. 145-256 (4 pl.); Nos. 5-6, pp. 257-270. 95. Révision des Cladocéres. (2 pl.) (Good bibliography.) Ann. d. Se. Nat. Zool. Ser. 7, T. 18, pp. 279-389. 32 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. Richiardi, S. "75. Sulle Sacculine. Atti della Soc. Toscana di Scienze Nat. Pisa. Vol. 1, pp. 136-146. Robin. 72, Observations anatomiques et zoologiques sur deux espéces de Daphnies. [Daphnia pulex et macropus.] (4 pl.) Journ. |’Anat. et Physiol. Robin et Pouchet. 8. Année, pp. 449-467. Saccardo, P. Andrea. ’64, (Cenni storico-naturali intorno agli animaletti) entomostracei viventi nella provincia di Treviso, (colla descrizione di un nuovo genere e coll’ indicazione delle poche altre specie di essi trovate nel resto delle provincie Venete. Con 1 tay. litogr. Treviso, 1864. 8°.) Sars, Georg Ossian. 61. Om dei Omegnen af Christiania forekommende Cladocerer. (Oversigt af de af ham i Omegnen af Christiania iagttagne Crustacea Cladocera.) Forhandl. Vidensk. Selsk. Christiania, 1861, pp. 144-167, 250-302. 63. Oversigt af de indenlandske Ferskvandscopepoder. (2 pl.) Ibid. (Aar 1862) Pp. 212-262. 64, (Beretning) om en i Sommeren 1863 foretagen zoologisk Reise i Christiania Stift. Nyt Mag. Naturvid. 13, pp. 225-259. ’64!. Indberetning om en i Pommeren 1862-63 foretagen zoologisk Reise in Christiania og Throndhjems Stifter. (Beretning om.en i Sommeren 1862 fore- tagen zoologisk reise i Christianias og Trondhjems Stifter. ) Ibid. 12, 1863, pp. 193 252. ’65. Norges Ferskvandskrebsdyr. Forste Afsnit. Branchiopoda. I. Cladocera Ctenopoda (fam. sidide a. kolopedidz). (4 pl.) Med Hs. Maj. Kongens Guldmedaille Prisbelomiet Afhandling. Christiania. Acs Vili iicpp: 74, Om en dimorph Udvikling samt Generationsvexel hos Leptodora. (1 pl.) Forhandl. Vidensk. Selsk. Christiania. (Aar 1873.) 15, pp. 1-15. 76, Prodromus descriptionis Crustaceorum. ’85, "On some Australian Cladocera raised from dried mud. (8 pl,) (Forhandl. Vidensk. Selsk. Christiania. No. 8,46 pp. -Abstract in: Journ. Roy. Mic. Soc. 1887, p. 953. Also in: American Naturalist, Vol. 21, Feb., 1887. p. 186.) Schmankewitsch, Waldimir. 75. Uber das Verhaltniss der Artemia salina Milne Edw.zur Artemia Mihlhausenii Milne Edw. und dem Genus Branchipus Schaeff. (1 pl.) Zeitschr. f. wiss. Zool. Bd. 25, Suppl. Heft 1, pp. 103-116. 77. Zur Kenntniss des Einflusses der d4usseren Lebensbedingungen auf die Or- ganisation der Thiere. Ibid. Bd. ? Schmarda, L. 85. Zur Naturgeschichte Aegyptens. Denkschr. d. k. Akad. d. Wissensch. zu Wien. VII. ENTOMOSTRACA OF MINNESOTA. 33 Schmeil, 0. 91. Beitraige zur Kenntniss der Siisswasser-Copepoden Deutschlands mit beson- derer Berticksichtigung der Cyclopiden. Inuaugural-dissertation. Univ. Leipzig. 8°, 40 pp. (In: Zeitsch. f. Naturwiss. (Halle), Bd. 64, Heft 1-2, pp. 1-40.) Schmeil, Otto. ; 92. Deutschlands freilebende Siisswasser-Copepoden. I. Teil: Cyclopide. (192 pp. 8 pl. and 3 text figs.) Bibliotheca Zoologica (Leuckart und Chun). Heft 15, I. Teil. 93. Id. II. Teil: Harpacticide. (102 pp., 8 pl. and 2 text figs. ) Ibid. Heft 15. II. Teil. Schneider, J. Sparre. ’84. Undersdgelser af dyrelivet i de arktiske fjorde. II. Crustaceer og Pycnog- onider indsamlede i Kvzenangsfjorden 1881. (5 pl.) Tromso Mus, Aarshefter. VII. 88 pp. Schoedler, J. Edward. ’46, Uber Acanthocercus rigidus, ein bisher noch unbekanntes Entomostracon aus der Familie der Cladoceren. (2 pl.) Arch. f. Naturgesch. Jahrg. 12, Bd. 1, pp. 301-374. 58. Carcinologische Beitrage. Die Branchiopoden der Umgegend von Berlin. 1. Beitrag. (1 pl.) : Jahresber. d. Louisenstadtische Realschule zu Berlin. 28 pp. 62. Die Lynceiden und Polyphemiden der Umgegend Berlins. Jahresb. d. Dorotheenstadt. Realschule zu Berlin. 63. Neue Beitrage zur Naturgeschichte der Cladoceren (Crustacea Cladocera) (3 pl.) Berlin. 4°. 80 pp. 65. Zur Diagnose einiger Daphniden. Archiv. f. Naturgesch. Jahrg. 31, Bd. 1. pp. 283-285. ’66. Die Cladoceren des frischen Haffs nebst Bemerkungen tiber anderweitig vor- kommende verwandte Arten. (3 pl.) Ibid. Jahrg. 32, Bd. 1, pp. 1-56. 77. Zur Naturgeschichte der Daphniden. Beitrage zur Kenntniss der systemat- ischen Angehorigkeit der Daphniden. Berlin, 1877. 4°. 1 pl. 24 pp. Scott, T. 88, A revised List of the Crustacea of the Firth of Forth. Sixth Annual Report of the Fishery Board for Scotland. Shaw, George. 1791. Description of the Cancer stagnalis of Linnzus. Trans. Linn. Soc. London. I. Siebold, Carl Theodor E. von. : 39. Beitrage zur Naturgeschichte der wirbellosen Thiere. (Uber Medusa, Cy- clops, Loligo, Gregorina and Xenos. ) Neueste Schr. d. Naturf. Gesell. in Danzig. Bd. 3, Heft 2. "71. Beitraige zur Parthenogenesis der Arthropoden. (2 pl.) WI. Uber die par- thenogenetische Fortpflanzung bei Apus und verwandten Crustaceen. Leip- Weta Srs SVLLEI 238 pp: 34 GEOL, AND NAT. HIST. SURVEY OF MINNESOTA. ”73,. Uber Parthenogenesis der Artemia salina. Sitzungsber. d. Konigl. Akad. d. Wissensch. zu Miinchen. Bad. 3, pp. 168-196. Smith, F. A. ’*61. Sur les Ephippies des Daphnies. (2 pl.) Nov. Act. Acad. Scient. Upsal. Ser. 3, Vol. 3, pp. 37-50. Spangenberg, Friedrich. 75. Zur Kenntniss von Branchipus stagnalis. (3 pl.) Zeitschr. f. wiss. Zool. Bd. 25, Suppl. Heft 1, pp. 1-64. 76, Uber Bau und Entwicklung der Daphniden. Vorlauf. Mittheilung. Gotting. Nachricht. 1876, pp. 517-537. Stimpson, Wm. : ’64, Synopsis of the Marine Invertebrata collected by the late Arctic Expedition under Dr. I. I. Hayes. Proce. Acad. Nat. Sc. Philadelphia. 1863. Pp. 138-142. Straus-Durckheim, Hercule Eugene. 119-20. Mémoire sur les Daphnias, de la classe des Crustacés. (1 pl.) Mémoires du museum d’hist. nat. T. 5, pp. 380-425; 6, pp. 149-162. (Paris, 1819, °20. 59 pp. Extr. des Annal. du Muséum d@’hist. natur. Tom. 5, 6.) ‘21, Mémoire sur les Cypris de la classe des Crustacés. (1 pl.) Ibid 7, pp. 33-61. Strom, H. 1765. Beskrivelse over ti norske Insekter Nr. 9, Tab. IX. Skrifter som udi det Kjobenh. Selsk. (Acta Havnie. ) Studer, Th. 78, Beitrage zur Naturgeschichte wirbelloser Thiere von Kerguelensland. Archiv. f. Naturgesch. Jahrg. 44, pp. 102-121. Templeton, Rob. 36. Descriptions of some undescribed exotic Crustacea. (3 pl.) Trans. Entom. Soc. London. Vol. 1, pt. 3, pp. 185-198. 37. Description of a new Irish Crustacean Animal (Anomalocera pattersonii). (1 pl.) Ibid. Vol. 2, pt. 1, pp. 34-40. 38. Id. (Zvea pattersonii). (1 pl.) Ibid. Vol. 2, pt. 2, pp. 114-120. Thallwitz, J. "90. Entomostraken [aus der Umgegend Dresdens]. VY. Jahresber. d. ornith. Beobacht. Stat. Sachsen. Pp. 75-80. Thomson, George M. 61. On anew Daphnia. Trans. New Zealand Inst. °83. On the New Zealand Copepoda. (7 pl.) Trans. N. Zealand. Instit. Vol. 15, pp. 93-116. 83. (New Zealand Copepoda II. New Zeal. Journ. Se. Vol. 1, No. 7, (Jan ), pp. 341-342.) ENTOMOSTRACA OF MINNESOTA. 35 ’84, On the New Zealand Entomostraca. (1 pl.) Ibid. Vol. II, 1879 (1878), pp. 251-263. Thompson, I. C. ’87. On some Copepoda new to Britain (found in Liverpool). Proceedings of the Liverpool Biological Society, Vol. I. Thompson, John V. 731. Memoir VI. Developmentof Artemis salinus or Brine Shrimp; demonstrative of its Relationship to Branchipus and the other Crustaceous Phyllopoda, and to those enigmatical Fossils, the apparently eyeless Trilobites with a new Species of Artemis and of Apus. Zoolog. Journ. V. Thorell, T. 59. . Bidrag till Kannedomen om Krustaceer, som levfai arter af Slegter Ascidia, L Till K. vet. akad. inlemnad d. 14 September. (Stokholm, Akad. Handl. IIL, 1859-60.) (In German in Zeitsch. f. d. ges. Naturwiss. Halle. Bd. 15, 1860, pp. 114-144.) Tilesius, W. G. 15, De Cancris kamtschaticis, oniscis, entomostracis et cancellis marinis micro- scopis noctiluscentibus; (cum appendice de Acaris et Ricinis Eames hanen) (4 pl.) Mém. de l’Acad. imp. des Se. de St. Petersbourg. T. 5, pp. 331-405. (4 maj. Petropoli. 1812.) 14-19, Ueber das naichtliche Leuchten des Meerwassers. Ann. d. Wetter. Gesellsch. f. d. ges. Naturkunde. Bd. 3, 1814, pp. 360-372. Fort- setzung. Bd. 4 (Neue Annalen Bd. 1), 1819, pp. 1-10. (2pl.) Toth, S. ’61. A budapesti kandicsfélék. Cladocera. Math. termtud. kozlem. Kiadja a m. tud. Akad. I. k. 61. Die Rotatorien und Daphnien der Umgebung von Pest-Ofen. Verhandl. d. k. k. zool.-botan. Gesellsch. in Wien. XI. Pp. 183-184. 762. Pest-Budan 1861 ben tal4lt Daphnidak. Mathem. term. tud. kozlem. Kiadja a m. tud. Akad. II. k. Trybom, Fil. 81. Jakttagelser om det lagre djurlifvet pa de platser utanfor Bohuslans kust, der sillfiske med drifgarn bedrefs vintern 1880-1881. Oefvers. Kgl. Vet. Akad. Forhdlg. Stockh. Arg. 38, No. 3, pp. 33-43. Turner, C. H. 792. Notes upon. the Cladocera, Copepoda, Ostracoda and Rotifera of SEELEY with descriptions of New Species. (2 pl.) Bull. Scient. Laboratories of Denison University. Vol. 6, pt. 2, pp. 57-74. 93, Preliminary Note on the Nervous System of the Genus Cypris. Journ. Comp. Neurology. Vol. 3, pp. 1-35. 931, Additional Notes on the Cladocera and Ostrocoda of Cincinnati. atic Portion. 2. Late Larval History of Cypris Herricki. spinifer, Herrick, not the same as I. longiremis, Sars. (2 pls.) ee Se. Labs. Den. Univ. Vol. 8, pt. I, pp. 1-18. 1. System. 3. Ilyocryptus TR rep Oe) SN He Sea NR ee ee a ee 36 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. 94, Notes on American Ostracoda, with Descriptions of New Species. (2 pl.) Ibid. Vol. §, pt. 2, pp. 13-26. ; Turner, Wm., and H. S. Wilson. 61. On the structure of the Chondracanthus lophii, with Observations on its Larval Form. Trans. Roy. Soc. Edinburgh. XXIII, pp. 67-76. Uljanin, W. N. 74, Cladocera et Copepoda de guelques lacs de la Russie centrale. 75, Crustacea of Turkestan. PartI. (In Russian.) 751, Reise in Turkestan von Al. Fedtschenko. II. Zool. Theil 7. Crustacea. Moscou. Vauzeme, Roussel de. 34, Description du Cetochilus australis nouveau genre de Crustacé branchiopode. (1 pl.) Ann. d. Se. nat. 2 sér. Zoologie I, pp. 330-338. Vejdovsky, Franz. 82. Thierische Organismen der Brunnenwasser von Prag. (8 pl.) Prag. 1882. 4°. 68 pp. Vernet, H. ’79. (Entomostracés de la faune profonde du lac Léman et description de la Moina bathycola n. sp. Pp. 526-535 of F. A. Forel’s) Matériaux pour servir A Vetude de la faune profonde du lac Léman. Bull. de la Soc. Vaud. de science. natur. Sér. IV,T. 15, No. 80. (1878.) Vogt, Carl. 77. Sur quelques Copepodes Parasites 4 Males Pygmées hahitant les Poissons. Mem. Inst. Genéva. 13. ‘78, L’Adaptation des Crustacés Copépodes au Parasitisme. Actes de la Soc. Helvétique des Sci. Nat. 60° Sess. (1877), pp. 121-139. Vosseler, J. ’86. Die freilebenden Copepoden Wiirttembergs und angrenzender Gegenden. (3 pl.) | Jahreshefte des Vereins f. vaterl. Naturkunde in Wirttemberg. Jahrg. 42, pp. 167-204. Also separate as: Inaug. Diss. (Tiibingen.) Stuttgart 1886. 8°. *89. Die Copepodenfauna der Eifelmaare. (1 pl.) Arch. f. Naturgesch. Jahrg. 55, Bd. 1, Heft 1, pp. 117-124. Wagner, Rudolphus. 36. Prodromus Historiz Generationis Hominis atque Animalium (sistens icones ad illustrandam ovi primitivi, imprimis vesicule germinative ét germinis in ovario inclusi genesin atque structuram, per omnes animalium classes mul- tosque indagatam. Acced. tabule dus eriincise. Roy. Fol. Lipsiz.) Walter, Alfred. ’88. Transkaspische Binnencrustaceen. I. Entomostraca. (1 pl.) Zool. Jahrbiicher. Abth. f. System. Geog. u. Biol. d. Thiere. Bd. 3, Heft 6, pp. 987-1013. pia Pane Sod We ARS a ith aa ana 4 ENTOMOSTRACA OF MINNESOTA. 37 Weber, M. 76. Ueber die Nahrung der Alansa vulgaris und die Spermatophore von Temora velox Lilljeborg. Arch. f. Naturgesch. Jahrg. 42. Weisman, August. 74, Ueber Bau und Lebenserscheinungen von Leptodora hyalina Lilljeborg. Zeitschr. f. wiss. Zool. Bd. 24. 76, Beitrage zur Naturgeschichte der Daphnoiden. I. Uber die Bildung von Wintereiern bei Leptodora hyalina. (3 pl.) Zeitschr. f. wiss. Zool. Bd. 27, Heft 1, pp. 51-112. Also separate: Leipzig, 1876. 8°. 64 pp. 77. + Beitrage zur Naturgeschichte der Daphnoiden. II-IV. (5 pl.) Ibid. Bd. 28, Hefte 1 u. 2. (II. Die Eibildung bei den Daphnoiden. Pp. 95-175. III. Die Abhangigkeit der Embryonalentwicklung vom Fruchtwasser der Mutter. Pp. 176-211. IV. Ueberden Einfluss der Begattung auf die Erzeug- ung von Wintereiern. Pp. 212-240.) °78. Id. V. Ueber die Schmuckfarben der Daphnoiden. (1 pl.) Ibid. Bd. 30, Suppl. Heft 1, pp. 123-164. 79, Id. VI. Samenbildung and Begattung bei den Daphnoiden. (6 pl.) VII. Die Entstehung der cyclischen Fortpflanzung bei den Daphnoiden. Ibid. Bd. 33, Heft 1, pp. 55-110; Heft 2, pp. 110-164. Above, I-VII, separate: Leipzig, 1876-79. Pp. XVI, 486. (15 pl.) Westwood, J. 0. 386, Cyclops. Partington’s Cyclopaedia. White, Adam. 55, A collection of documents on Spitzbergen and Greenland. London. 57. A Popular History of British Crustacea comprising a familiar account of their classification and habits. London, 1857. 16°. 360 pp. Wierzejski, A. 81. O Faunie jezior Tatrazaniskich. Pamietnika Tow. Tatrzaniskiege. 82. Materyjaly do fauny jezior tatrzanskich. (27 pl.) Spraw. Kornis. fizyjagraf (Akad. umieg.) Krakowie. Vol. 16, pp. 1-24. Also separate: (Polish.) Abstract by A. Wierzejski in Biol. Centralb. Bd. 2, No. 23, p. 736. 83. Zarys fauny stawOw tatrzanskich. Pannétnika Tatrzanskiego, VIII, Kra- kowie. 87. O. krajowych skorupiakach zrodziny Calanide, Nozgrawn (Rozpr.) i Spraw. (1 pl.) Wydz. mat. przyr. Akad. Umiej. Vol. 16, p. 13. Zacharias, Otto. '85. Uber die améboiden Bewegungen der Spermatozoen von Polyphemus pedi- culus (de Geer). (1 pl.) Zeitsch. f. wiss. Zool. Bd. 41, Heft 2 (Dec., 1884), pp. 252-258. 35 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. °851, Studien iiber die Fauna des Grossen und Kleinen Teiches im Riesengebirge. (1 pl.) Ibid. Bd. 41, Heft 3 (March, 1885), pp. 481-516. 87, Zur Kenntniss der pelagischen und littoralen Fauna norddeutscher Seen. (1 pl.) Ibid. Bd. 45, Heft 2 (April, 1887), pp. 255-281. 89, Bericht tiber eine zoologische Exkursion an die Kraterseen der Eifel. Biolog. Centralblatt. Bd. 9, No. 2, pp. 56-64; No. 3, pp. 76-80; No. 4, pp. 107- 118. : Zaddach, E. G. ’44, Synopseos Crustaceorum Prussicorum prodromus. 4. Regiomonti 1844. 39 pp. "56. Holopedium Gibberum, ein neues Crustaceum aus der Familie der Branchio- poden, beschrieben. (2 pl.) Arch. f. Naturgesch. Jahrg. 21, Bd. 1, pp. 159-188. Zenker, Wilh. 51, Physiologische Bemerkungen iiber die Daphnoiden. (1 pl.) Mueller’s Arch. f. Anat. und Physiol. 1851, pp. 112-121. (Physiological remarks on the Daphnide. Q. T. Mic. Sc. Vol. 1, 1853, pp. 273- 278.) 54. Anatomisch-Systematische Studien tiber die Krebsthiere (Crustacea). (6 pl.) Archiv. f. Naturgesch. Jahrg. 20. Also separate: Berlin, 1854. 8°. IV, 115 pp.- 54), Monographie der Ostracoden. (6 pl.) Ibid. Jahrg. 20, Bd. 1, pp. 1-88. COPEPODA OF MINNESOTA _ BY Cc. L. HERRICK ORDER COPEPODA. This extensive order contains minute and predominatingly preda- ceous animals which constitute no inconsiderable part of the fauna of fresh and salt waters. They serve a beneficent purpose both as seav- engers and as providing food-supply for the fry of fishes and other aquatic animals. Copepoda are never inclosed in a bivalved shell, but ordinarily exhibit a more or less elongated cylindrical form, composed of two obvious subdivisions. There are a few species which, by the great pro- longation and expansion of some of the tergites or dorsal shields, seem to simulate shelled Crustacea. The anterior part of the body, or ceph- alothorax, is composed of ten somites which are frequently consider- ably united or fused. Five of these segments constitute the head and bear respectively the following appendages: first, a pair of several- to many-jointed antenne, which are never primarily sensory in function, although they usually are provided with sense hairs or other like organs; second, a pair of two-branched antennules, which sometimes become almost simple or prehensile; third, a pair of mandibles in the form of masticatory or piercing organs, these being usually provided with a palpus; fourth, a pair of maxille of various form and fune- tion; fifth, a pair of maxillipeds which not infrequently subdivide in later life to form what appear to be two distinct pairs. The five thoracic segments have each a pair of swimming feet con- sisting typically of a two-jointed base and two similar, three-jointed rami. The symmetry is frequently broken by the retardation of the development of the inner or outer ramus, while the fifth pair of feet may become rudimentary and in various ways subserve the organs of sex. The five abdominal segments are nearly devoid of appendages and are continued posteriorly by two caudal stylets which bear strong sete, constituting, in many forms, a tail-fin or spring. All Copepoda, even such as are, in later life, parasitic, begin their existence as free-Swinning nauplii. Though the vast majority of genera and species are marine, it would seem that fresh-water Copepoda make up in the number of indi- viduals what they lack in variety. 42 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. As we are dealing primarily with the fresh-water species, no lengthy description of the group is here necessary. The earlier history of our knowledge of the animals of this order is given by Baird. According to this authority, the first to mention any fresh-water species of this group was Stephan Blankaart,* in his Schou burg der Rupsen, Wormen, Ma’ den, en vliegende Diekens tot Amster- dam. Leeuwenhoek adds numerous interesting details, and is accredited by Hoek with being the first to discover the relation between the remarkably diverse stages which occur in the history of the Cyclops. However, it is evident that he had a very incomplete knowledge of the metamorphoses. De Geer gives rather characteristic figures of a Cyclops in Memoires pour servir al Histoire des Insectes, vol. vii, 1778. Mueller, in his great work on Entomostraca, adds new facts, defines species and forms the genus Cyclops. Ramdohr, in 1805, gave sundry additions to the knowledge of these animals in his Beitrage zur Naturgeschichte einiger Deutschen Monoculus- arten. In this work the post-embryonic history is quite fully outlined. Jurine, in his classic work Histoire des Monocles qui se trowvent aux Environs de Geneve, 1820, crystallized what previous authors as well as his own original experiments had brought to light of the anatomy and biology of these animals. Ferussac (Memoire sur deux novelles especes d’ Entomostraces) re- describes known species. Gunner, Stroem, and Viviana seem to have had little effect on the knowledge of the group, though they wrote prior to Jurine. A recent author attempts to revive the names of Jurine, though hitherto it has been thought hazardous to attempt a specific identifi- cation. The German author, C. L. Koch, who only incidentally studied this group, distinguished more or less perfectly a variety of species which have been reinstated in our literature by Rehberg. Although this proceeding seems quite unjust to the careful authors whose de- scriptions are recognizable in themselves, the law of priority must probably prevail. Koch’s Deutschlands Krustaceen appeared in 1838. Baird’s British Entomostraca, without greatly extending our knowl- edge of this order, put in readable form and made available to English readers what was known, and added interesting facts. He distin- guished two families of Copepoda, (1) Cyclopide, (2) Diaptomide. The first included the genera (1) Cyclops, (2) Canthocamptus, (3) Arpacticus, (4) Alteutha; and the second the genera, (1) Diaptomus, (2) Temora, (3) Anomlocera. * Latinized Stephanus Blanchardus. Hoek recognized Cyclops brevicaudatus or C, bicuspidatus as the ono described, chiefly through knowledge of the present inhabitants of the locality. ENTOMOSTRACA OF MINNESOTA. 43 Fischer, who contributed not a little to our knowledge of the dis- tribution of fresh-water Cladocera, was the next to describe valid spe- cies. He described the species found near Moscow and St. Peters- burg, Russia. The justly famous Swedish naturalist, W. Lilljeborg, who has left his mark on so many branches of natural science, has not neglected the microscopic Crustacea of his fatherland. Om de inom Skaane foere- kommande Crustaceer af ordningarne Cladocera, Ostracoda och Copepoda, is the somewhat formidable title of his work, published in 1855. He recognized the following genera of Copepoda: Diaptomus, Temora, Dias, Ichtyophorba, Tisbe, Tachidius, Harpacticus, Canthocamptus, and Cyclops. A species each of Diaptomus and Canthocamptus is described, and two species of Cyclops. (It would seem from authors’ quotations that other species are described in an appendix, but the copy I have seen lacks this.) The author who has done most for micro-carcinology in general is Carl Claus of Vienna. His principal works are: 1. Das Genus Cyclops, etc. In Wiegmann’s Archiv fiir Naturgeschichte, 1857. 2. Weitere Mittheilungen ueber die einheimischen Cyclopiden, The same, 1857. 3. Die Freilebenden Copepoden, 1863. The later work especially is indispensable to the student of Cope poda, though in reality it is more important in respect to marine Co- pepoda., In the meantime a work appeared in Norwegian, with Latin de- scriptions, from the pen of G. O. Sars. This has been largely over- looked. It is, unfortunately, unaccompanied by plates, but the de- scriptions bear the stamp of the naturalist. A little later a second brief contribution from this author was pub- lished, but I have not seen it. Sir John Lubbock in 1863 describes species of fresh-water Copepo- da, but the publication seems no longer necessary. Heller, in Tyrol, Fric, in Bohemia, and Uljanin, in Asia, have studied the Oopepod fauna. A Russian paper by Poggenpol and Uljanin is quoted as 4 Cata- logue of the Copepoda, Cladocera and Ostracoda of the vicinity of Moscow, by Rehberg, and as from the Protokolle der kais.-naturw. anthropol. und ethnogr. Ges. in Moskau, but by Cragin, who publishes a translation apparently of the same paper in part, as from the Bulletin of the Friends of Natural History. Hoek, in the Tijdschrift der Nederlandsche Dierkundige Vereeniging (Magazine of the Zoological Society of the Netherlands), 1875, and later in German in the Miederlaindisches Archiv fiir Zoologie, gave excellent 44 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. figures and descriptions of some species which Claus had too hastily treated. In 1878 A. Gruber gave descriptions of Two fresh-water Calanide. In the same year the first volume of Brady’s fine British Copepoda appeared. A purely technical work and briefly written, it is yet very comprehensive and in the main reliable. This is a worthy suc- cessor of the Ray Society’s earliest publication on Entomostraca— Baird’s great work. In the sixth volume of the Abhandlungen d. naturwissenschaftlichen Verein zu Bremen, Herman Rehberg gives a systematic review of syn- onomy, and in the revision unites several species in a manner that the present writer had independently been driven todo. It is prob- ably impossible either to substantiate or positively deny some of this writer’s identifications of the species of the older authors. This paper also contains an observation of a hermaphorditic Cyclops, which it is interesting to compare with similar anomalies, described by Kurz in Cladocera. In the seventh volume of the same periodical, Rehberg adds to and modifies some of the views expressed above. In the same number is a description of a new species of Temora by Poppe. (The same species occurs in the semi-saline waters of the Gulf of Mexico, and had well- nigh gone into print under a new name when this was seen. ) In the above review we have noticed only the more important foreign works on the Copepoda and those including fresh-water forms. Dana’s magnificent Crustacea of the Wilkes’ Exploring Expedition is not included, because it is essentially restricted to the marine species, the few descriptions of fresh-water species being quite valueless. Among important contributors to the exclusively marine Copepoda, are Boek (Oversigt over Norges Copepoder and Nye Slegter og Arter af Saltvands- Copepoder), Brady and Robertson, Lubbock and Claus. The history of the American literature can be quickly traced. Say described imperfectly an American species of Cyclops in 1818. Haldeman describes in volume 7, of the Proceedings of Philadel- phia Academy of Science, p. 331, Cyclops setosa (which may be C. ser- rulatus). Pickering very imperfectly described a new genus of Cope- poda from Lake Ontario in Dekay’s Zoology of New York. This genus is, most likely, Epischura of Forbes, and, in strictness, ought to rank it. In 1877 appeared A List of Illinois Crustacea, by Professor Forbes, in which two species of Copepoda were described which may rank as the first descriptions, at all adequately framed, of American members of the order. In the Annual Report of the Minnesota State Geologist for 1878, a brief article by C. L. Herrick outlined, in the light only of the then English literature, the micro-crustacea of Minnesota. No at- pe ND aah th laa Cha) REA vhs heen ee sats atl ' ENTOMOSTRACA OF MINNESOTA. 45 tempt was made to treat the Copepoda, but two species of Diaptomus are indicated which will prove valid. Occasional papers in the American Naturalist and elsewhere follow, till, in July and August of 1882, Professor Forbes added two new genera and several species of Copepoda, constituting by far the most considerable addition to the subject yet produced. In the Report of the State Geologist of Minnesota for 1881, C. L. Her- rick makes a considerable addition to the knowledge of American Cyclopide, enumerating ten species, of which six seemed new. This writer also describes a new genus and several new species of Calanide, some of which unfortunately are identical with those described by Forbes and published about simultaneously. In April, 1881, V. T. Chambers gave an account of a species of the Harpacticide, referred by him to Zachidius. The species is especially interesting on account of its novel habitat. Zachidius (?) fonticola Cham.» is found in saline waters of Big Bone Springs, Ky., and is thus very distant from its marine congeners. It is perhaps doubtful if its gen- eric reference can be sustained, but the species is of great interest. The Diaptomus described by the same author is not recognizable. Several articles in the Naturalist bring the bibliography up to May, 1883, when F. W. Cragin published in the Trans. Kansas Academy of Science, A Contribution to the History of the Fresh-water Copepoda. In this paper ten species of Cyclops are described or mentioned. The author ignored previous American literature and thus adds somewhat tosynonomy. The plates are lithographic, and are carefully, if not artistically, prepared. A valuable feature is the translation of the descriptions of Poggenpol’s species from the Russian. These papers, together with the outline presented beyond, it is hoped, will form a basis for future work. To the above, which is reproduced without change from the first edition, it may be added that there has been a considerable degree of desultory activity in the study of the Copepoda in Europe since the appearance of this work. This has been especially marked in the case of the Calanide, and, in particular, in the genus Diaptomus, in which the confusion resulting from confounding many species under one name has been finally removed and the real specific characters differentiated. Among the most important of these papers are the following: De Guerne and Richard: Revision des Calanides @ Eau douce; Brady: Revision of British species of Fresh-water Cyclopide and Calanide; Schmeil: Deutschland’s Freilebende Siisswasser Copepoden:- American literature since 1884 has been but little augmented, the fol- lowing papers being the only important ones: Herrick: Contribution to the Fauna of the Gulf of Mexico and the South, 1887; Forbes: On Some ; 46 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. Lake Superior Entomostraca, 1891; Marsh: On the Deep- Water Crustacea of Green Lake, 1891; Forbes: A Preliminary Report on the Aquatic In- vertebrate Fauna of ‘the Yellowstone National Park, 1893; Marsh: On the Cyclopide and Calanide of Central Wisconsin, 1893. (?) While it is probable that comparatively little remains to be done in the systematic study of North American Copepoda except in the west and in mountainous and brackish stations, yet there are few more attractive fields than that offered by the study of the biological conditions under which these forms appear. The processional ap- pearance of several species in the same pool in the spring, the effects of stagnation on the organization, and the peculiar heterogenesis or polymorphism due to age, are all capable of yielding valuable addi- tions to theoretical biology. While much care and attention are requisite, and considerable collateral information, yet the Cladoceran studies of Professor Weismann afford a suitable model and induce- ment. Ina purely systematic paper like the present one no attempt can be made to indicate these lines of work. FAMILIES OF THE FRESH-WATER COPEPODA. I. Calanide. Body elongate; abdomen more slender and quite distinct from the thorax. Antenne long, 23-to 25-jointed; in the male that of the right side modified for prehension. First four pairs of feet two-branched, outer branch three-jointed. Fifth feet several- jointed, those of the male prehensile; dissimilar on the two sides. Ovisac single. Habit strongly natatory. II. Cyelopidw. Cephalothorax compact, ovoid; abdomen slender. Antenne usually shorter than the cephalothorax, both geniculate in the male, 8- to 18-jointed. Second antenne (antennules) one-branched. Fifth feet rudimentary, a sixth pair sometimes present, especially in the male. Ovisacs double, lateral. Habit natatory. III. Harpacticide. Body cylindrical or flattened; abdomen not sharply distinct. Antenne short, not more than 10-jointed, those of the male both geniculate. Antennules palpate. First pair of swim- ming feet usually prehensile. Fifth feet foliaceous, somewhat dissimi- lar between the sexes. Ovisac usually single. Habit creeping or sub-natatory. FAMILY CALANIDE. This group is pre-eminently marine and contains diverse and graceful forms, mostly with very elongated bodies and antenne. Of the six genera here enumerated as more or less habituated to the use of fresh water, two are found as yet only in America and one is con- fined to Europe. ENTOMOSTRACA OF MINNESOTA. 47 Heterocope, namely, is very near Epischura, both being restricted to fresh water. Diaptomus and Osphranticum are likewise only ac- cidentally found in the seas, though their nearest allies are marine. The genus Limnocalanus is as yet found in America only in the Great Lakes. In the distribution of genera we here follow Brady, whose defini- tion of the family Calanide, including Calanide, and Pontellide of au- thors, we quote: ‘‘Body elongated; composed of from ten to twelve [obvious] segments. Abdomen nearly cylindrical, much narrower than the cephalothorax and prolonged at the posterior extremity into two more or less cylindrical caudal branches [stylets]. First segment of thorax often anchylosed with the head; fourth and fifth segments also often coalescent. Head only rarely divided into two segments. Anterior antenne very long and composed of twenty-four or twenty- five joints; that of the right side in the male often modified for grasp- ing [geniculate]. Posterior antenne large, composed of a basal joint, from which spring usually two branches, the primary branch consist- ing of two, the secondary of several joints. Mandibles strongly toothed at the apex, palp (usually) two-branched. Maxille strong, and provided with a many-lobed palp. Foot-jaws strongly devel- oped: first pair very broad; the basal joints having on the inner mar- gin wart-like processes, from which spring long ciliated bristles; the distal extremity divided into three short joints which are thickly be- set with strong and long, ciliated sets; second pair longer and more slender, basal portion forming two long oval joints; apical portion usually four-to six-jointed. First four pairs of feet two-branched, the outer branches always three-jointed. Fifth pair either like the fore- going, or much modified, unlike on the two sides, and in the male forming clasping organs. A heart is present. Eyes either median and stalked or paired (lateral) and sessile; in the latter case being often coalescent and composed of several lenses. Sexual organs in the female symmetrical, in the male asymmetrical. Ovisac single, borne in front of [below] the abdomen. The Calanide are distributed over the whole globe, and yet the limitations of range are much more strict than in the other groups. Thus no species of the eastern continent has been positively identified in America, while the majority of the Cyclopidw of America are old world species or vicarious forms. Range of altitude is also limited, and the delicate organization of the Calanide responds to slight changes of the environment. The - origin of our fresh-water genera from the marine forms in compara- tively recent times is on many accounts very probable. The forma- tion of large inland bodies of fresh water was an essential pre- Te ee ee” en ee OLE ele oe > 48 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. requisite, and the limitations of range in themselves point to a more recent origin than the other groups of micro-crustacea; nor is it diffi- cult to trace the connecting links in many cases. KEY TO THE FRESH-WATER GENERA OF THE CALANIDE. I. FIFTH FEET OF THE FEMALE BI-RAMOSE. a, Inner rami of all the swimming feet three-jointed. * Inner ramus of the right male fifth foot three-jointed. + Outer ramus of the right male fifth foot two-jointed. Limnocalanus, 48 tt Outer ramus of the right male fifth foot three-jointed. Osphranticum, 85 ** Inner ramus of the right male fifth foot reduced. . . . *Boeckella. b. Inner rami of the first swimming feet two-jointed. . . . Diaptomus, 54 c. Inner rami of all the swimming feet two-jointed. . . . . . Broteas, 80 Il. FIFTH FEET OF THE FEMALE UNI-RAMOSE. a. All the swimming feet with the inner ramus one-jointed. * Abdomen symmetrical, not prehensile in the male. . Heterocope, 80 ** Abdomen unsymmetrical, with apse acne 5 in the Wales. a0 . . . . Epischura, 81 b. First swimming foot with one;jointed inner ramus, the rest two- JOINLE. > eS cise a . . . . . . HEurytemora, 49 c. Swimming feet with thine sound 4 inner rami. * Fifth foot of the male one-branched. . . . Pseudodiaptomus, 53 ** Fifth foot of the male with one-jointed innerramus. . . *Poppella. GENUS LIMNOCALANUS Sars. 1863. Cephalothorax six-jointed, slender, last segment never divaricate. Abdomen in the female three- or four-jointed (not including stylets), in the male five-jointed. Caudal stylets elongated with five sete. First antenne 25-jointed, shorter than the body; in the right antenna of the male a geniculate joint between segments 18 and 19. Second pair of maxille, strong, eight-jointed, last joint unguiculate. Feet bi-ramose, those of the first four pairs with three-jointed rami. Outer ramus of fifth feet in the female three-jointed, with a claw-like process from the second segment; inner ramus like those of the other feet. The outer ramus of the right foot of the male more conspicuously modified, apparently two-jointed, with a long apical claw. This genus very closely approaches Centropages, which latter is its marine prototype. The genus is represented by two species, one of which is circumpolar, the other occurring in China farther south. * Not described by the author. See plates. a) Say - , “rs 2 = i ENTOMOSTRACA OF MINNESOTA. 49 (Species preceded by an asterisk have been reported in America.) * Limnocalanus macrurus Sars. PLATE I, Fias. 1-4. Centropages grimaldii, De Guerne ’86. Limnecalanus macrarus var. auctus, Forbes ’87; Sars ’62; Nordquist ’88; De Guerne and Richard ’89; Marsh ’92. The subcylindrical three jointed abdomen is longer than the elon- gate oval six-jointed thorax. The stylets are very long, spiny and ciliated. Antenne hardly reaching the penultimate abdominal seg- ment. The claw of the female fifth foot armed with fine, sharp spines. The claw of the male right fifth foot is thick and bears two spines internally. Color generally hyaline. Length about 2.0 mm. Limnocalanus sinensis Poppe. De Guerne and Richard ’89. This smaller and rather depauperate form from China may be recognized by the fact that the claw of the fifth foot of the female has strong and irregular teeth and that of the right fifth foot of the male is slender and flexuous. The abdomen is shorter than the thorax. Length 1.65 mm. GENUS EURYTEMORA Giesbrecht. (Temorella of Claus, Poppe, Nordquist, Herrick.) Relatively robust; cephalothorax six-jointed; frontal processes present. Abdomen of the male, five-jointed, of the female, three- jointed. Caudal stylets slender, often very long relatively; apical sete four, also a similar lateral seta. Antenne 23-or 24-jointed, about as long as the cephalothorax. In the male 20-jointed with the geniculation between segments 18 and 19. Four pairs of bi-ramose Swimming feet, the first pair with a one-jointed inner ramus, the second to fourth pairs with two-jointed inner ramus. Fifth pair of feet in the female simple, similar, penultimate segment produced into a strong hook process; fifth feet of the male uni-ramose, each three- jointed, dissimilar, last joint of the right foot unguiform, of the left expanded. The genus Temora was founded by Baird, to receive one of the Calanide found abundantly on the English coast and since identified in various places along the shores of the German ocean. Much con- fusion has existed from the first in the nomenclature of this group re- sulting, in the first place, from the assumption that the type of the genus Temora is identical with Monoculus finmarchicus of Gunner, falsely identified with Cyclops longicornis of Mueller, and later from the fact that the male of one species has been wedded by our synon- omy to the female of a distinct though closely allied form. PTET Re eR Ne or ke On he ee 50 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. Still later it became evident that two sections could readily be distinguished within the genus which have since then been elevated to generic rank by Claus. Both these groups agree in several charac- ters, such as the following: Head distinct from the thorax, fourth and fifth thoracic segments closely united, frequently only the lateral or pleural portions of the latter being evident, abdomen composed of four segments in the male and three in the female, antenne shorter than the body, 24-(or 25?) jointed, right male antenna geniculate, in- ner rami of swimming feet, one-or two-jointed, in the female small, in the male prehensile. As restricted by Claus, the genera stand re- lated as shown by the following tabular diagnosis: Temora. Antenne of male 24 jointed, genicu- lation between joints 18 and 19. Max- illa and maxillipeds rather large. First foot with two-jointed inner ramus. Fifth feet one-branched, the left in the male three-jointed, dactylate, right two-jointed, unguiculate, in the female apparently two-jointed. Habit, marine. Sp. 1. T. longicaudata Lubbock (—T. jinmarchica Baird, etc.). Angle of last abdominal segment rounded, left foot of fifth pair in male three-jointed, with a long, immovable process on the first joint, the two remaining forming an apposable clasper, antennze as long as whole body. (North Sea.) Sp.2. T. armata Claus. Angle of last abdominal segment produced for- ward, left foot of fifth pair in the male with the terminal joint expanded into a plate, antenne reaching nearly to end of the abdomen. (Mediterranean. ) Sp. 3. T. dubia Lubbock. (As iden- tified by Brady.) Exactly as in T. ar- mata*, save that the antenne are said to be about as long as the cephalothorax. (Pacific and Atlantic Oceans. ) * The agreement is so close, even in minute details, that a varietal distinction at the utmost seems demanded. See Claus, Ueber die Gattun- gen Temora und Temorella, and Brady, Chaillen- ger Copepoda. Eurytemora. Antenne 24-(25?) jointed, genicula- tion between joints 18 and 19. Max- ile and maxillipeds quite short. First foot with 1-jointed inner ra- mus. Fifth feet one-branched, both three- jointed, the left with an expanded apex, the right with a strong claw, in the fe- male obviously three-jointed, the pen- ultimate segment bearing a strong spine. Habit sub-marine or fluviatile. Sp. 1. E. velow (Lillg.) Brady (=7. clausii Hoek). Penultimate joint of the fifth foot of female with a single spine externally, caudal stylets four to five times as long as wide and feebly spined. (Scandinavian and North Eu- ropean coasts. ) Sp. 2. EE. affinis Poppe. Last seg- mentof thorax produced. Penultimate segment of fifth foot in the female, with two spines externally, caudal stylets six to seven times as long as wide. Segmentation of last joints of male an- tenn more obvious. - (Same localities and rivers Rhine, Elbe, ete.) [See be- low on TZ. hirundo.| Poppe very posi- tively declares 7’. clausii to be identical with the 7. velox of Lilljeborg, but Claus explains that the male seen by Lilljeborg was 7. clausii. As identified by Brady, in England, 7. velox evi- dently corresponds to T. clausii, whhic should therefore probably yield priority to the older name. E. affinis occurs very abundantly in rivers and estuaries of, as well as in the Gulf of Mexico. Sp. 3. . lacustris Poppe. Last seg- ment of thorax rounded. Penultimate segment of fifth foot of female with two spines. Caudel stylets of female about as long as broad. From fresh-water lakes, Holstein, Sweden, Finland, ete. ENTOMOSTRACA OF MINNESOTA. 5 * Eurytemora affinis Poppe. PLATES I, Frias. 5-10; LX, Fias. 8-15. Lilljeborg ’53 (Temora velox); Poppe ’80 (Temora affinis) ; Claus ’81 (Temora affinis); Giesbrecht ’811 (Eurytemora hirundo). Form rather robust, about 1.60 mm. long, variously ornamented with colord markings; head separated by an obvious suture from the thorax, rounded anteriorly, with small forked beak; antenne about as long asthe thorax, 24-jointed, the twelve basal joints being quite short and uniform, in the right male antenna geniculated and thickened be- yond the twelfth, the geniculation being between the eighteenth and nineteenth, the seventeenth and eighteenth segments furnished with comb like or file-like plate against which plays a similar shorter plate on the nineteenth; the antennules short, three-jointed ramus with twelve set, two-jointed ramus with about fifteen; jaw. with eight acuminate teeth and a small spine; mandiblar palp with a two-jointed and four-jointed ramus, the former with seven terminal and four lat- eral setve; maxilliped very small, six-jointed; first pair of feet with the inner ramus one- the other three-jointed, remaining swimming feet, two- and three-jointed; fifth foot in the female with three joints (appar- ently four), the basal bearing a single external spine, the second, two external spines and a strong internal process, the terminal joint a long pectinate seta and a small spine; the fifth feet of the male both four- jointed, the right terminating in a long, irregularly excised claw and the left in a fan-shaped expansion with a central spine. The abdomen is five jointed in the male and terminates in two long slender stylets, but sparsely beset with bristles along the inner margin, while in the female the abdomen is three-jointed and the shorter stylets are densely spinous and bear numerous fine setze medianly. The second segment of the abdomen in the female is produced into a spiniferous process with small spines on its sides. The caudal stylets are about six times as long as wide in the female and nearly eight times in the male, the preceding segment being densely covered with short spines in the former, while in the latter there is on either side a cluster of longer stylets. The eggs are carried in a large spherical mass beneath the abdomen as in Osphranticum (Potamoichetor). The one-jointed ramus of the first foot bears seven sete, the terminal joint of the other ramus, five setee and three spines; the second segment of the inner ramus of second and third feet bears six sete, its predecessor three, while the terminal segment of the outer ramus carries five set, one long, ser- rated, apical spine and a short external spine; the fourth foot has but five setze on the apical segment of inner ramus and five sete, a ser- arted spine and two small spines upon the opposite branch, 4 4 5Z GEOL, AND NAT. HIST. SURVEY OF MINNESOTA. This species was first noticed in America by the writer, in an ap- pendix to his paper in the twelfth annual report of the state geologist of Minnesota. Careful study of abundant material since then shows the identification well-founded, although a few slight differences be- tween this and the north European species can be detected which are by no means so great as the variations in the figures of the several European authors who have described the species. Should it prove that this like other Calanide is dimorpbous T. clausii may disappear and the old name 7. velox will then be restored for both forms. Claus is certainly in error in calling the fifth pair of feet four- jointed, as shown by his own figures and especially those of Poppe.. Great interest attaches to this find, because it seems to indicate that the same morphological species has arisen under similar conditions in isolated stations. Should the species be found along the Atlantic coast, however, this assumption will be unnecessary. The curious resemblance, amounting almost to identity, between the Temora armata of Claus and Brady’s TY. dubia is likewise instruct- ive, leaving very little doubt of close genetic relationship. Boeck’s description of 7. inermis is here translated for the sake of completeness. (See Oversigt over de ved Norges Kyster iagttagne Cope- poder; Vidensk. Selskab. Forhandlinger, 1864, p. 16.): Length about 1.50 mm., transparent, colorless, with yellow viscera and a yellow band on the posterior part of the head and another upon the first segment of the abdomen. The body greatly elongated, slen- der. Head divided by a transverse suture into two parts, likewise the fourth and fifth segments distinctly separated. The fifth segment in the male rounded, in the female accuminated. The first joint of the abdomen in the male, but the middle one of the female, the short- est. The caudal appendages elongate, but shorter upon the abdomen of the male. The outer seta attached nearer the middle than the end of the caudal stylets. The anterior antenna of the male is strongly swollen in the middle and is armed with small spines upon the eighth to the twelfth joints. Last foot of the female two-jointed, first seg- ment short; second longer, oval, provided on the outer angle with a spine, on the inner with a longer curved spine-like process, at the apex is along, straight spine. The fifth legs of the male are three- jointed; second joint of left limb shortest, the third expanded at the end; first joint of the right foot long, but less broad; spines on the inner angle very small; third segment rather longer and provided at the end with simple teeth. The Temorella (Eurytemora) hirundo of Giesbrecht differs from 7. afinis only in three very significant particulars: first, the body is more slender; second, the caudal stylets are considerably longer; third, the ENTOMOSTRACA OF MINNESOTA. 53 ~ last segment of the thorax is rounded instead of acute, and bears minute bristles. The close agreement of the other parts suggests a local race or variety, but it may be best to retain the name notwith- standing. GENUS PSEUDO-DIAPTOMUS Herrick. Resembling Metrida and Diaptomus; compactly framed; cephalo- thorax six-jointed, last two segments coalescent above; head ‘rounded in front, beaked; eye small; antenne appearing 22-jointed in both sexes, longer than the thorax; the right male antenne geniculate as in Diaptomus; antennules bi-ramose, both rami rather short, inner one seeming but two or three-jointed; mandible ten-toothed; maxillipedes well developed; feet all bi-ramose save the last, both rami three- jointed; first feet smaller; fifth feet with inner ramus obsolescent, in the male nearly as in Diaptomus, in the female rather slender, simple, three-jointed; abdomen in the female three-jointed, in the male five- jointed; stylets in the female longer; ovisac single; spermatophore pear-shaped, liable to be mistaken for eggs. * Pseudo-diaptomus pelagicus Herrick. PLATE I, Fias. 11-17. Herrick, ’84 and ’87. Rather compact; thorax alike in the sexes, antenne short, seeming 22-jointed; first foot small, both rami three-jointed; fifth feet in the male with but small rudiments of the inner rami, basal portion heavily armed with short teeth, otherwise almost as in Diaptomus; fifth feet of female slender, alike; abdomen in male very slender, with short stylets armed with five terminal sete and a series of bristles on the inner margins, distal margin of segments of abdomen toothed; a series of spines also ornaments the middle of the first segment below; abdo- men of female short and very spiny, first joint thick, second slender, oblong, third joint short; length of abdomen supplemented by that of the elongated stylets, which are spinulous on the edges; ovisac ovoid, eggs numerous; opening of operculum vulvz with lateral projecting | lips. This species is ornamented with irregular markings of brownish color which gives it a strange appearance not observed in any other Copepod. The size is like Temora velox, which the female resembles a little, a resemblance enhanced by the elongated stylets. This genus affords an illustration of a ‘‘missing link’’ connecting the fresh-water genus Diaptomus with its fellows of the sea. In most respects the species closely resembles Diaptomus, while in others it ap- proaches Drepanopus, and in still others Hucheta. The entire reduc- 54 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. tion of the inner branches of the fifth feet in both sexes is especially remarkable in view of the three-jointed inner rami of all the other feet. The fifth foot in the male is exceedingly like that of Drepanopus pectinatus Brady, while those of the female are on the same numerical plan; in that genus, however, the male antenna is not geniculate and the first foot has the inner ramus one jointed, The genus Hucheta isa somewhat miscellaneous assemblage, with some species resembling Pseudo diaptomus. In some respects Centropages is likewise similar. GENUS DIAPTOMUS Westwood. 1836. Cyclopsina—Milne-Edwards. Glaucea— Koch. Pontie—Ouchakoff. paphauanenas composed of seven segments, of which the cephalic two are more or less closely fused to form the head. Abdomen nar- row and shorter than the thorax, with three obvious segments in the female and four in the male, the last bearing two short stylets. Each caudal stylet is armed with five sub-equal plumose sete and one smaller internal bristle. Antenne of the first pair long, 25-jointed; in the male geniculate between the eighteenth and nineteenth joint and variously. thickened and armed, the penultimate segment often provided with a curved hook. Second antenne (antennules) two- branched; the exterior branch seven-jointed and bearing apically sev- eral long sete, inner ramus shorter and two-jointed. The mandibles armed with about nine acute teeth and provided with a bi-ramose palp. The maxille of the first pair are very short and armed with closely set sete. The second maxille, or maxillipeds, are long and directed cephalad, seven-jointed. The first pair of swimming feet has a two-jointed inner ramus while each of the three pairs following has both rami three-jointed. The fifth pair of feet are dissimilar between the sexes and furnish the most important specific characters. In the female the two feet are alike and the inner ramus is reduced or rudi- mentary, often one-jointed. The external ramus develops a strong claw from the penultimate joint, while the small apical segment bears one or more small spines. The fifth feet of the male are dissimilar, five-jointed, the inner rami rudimentary, the right limb having a long apical claw on the outer branch. The species are generally slender and graceful, the antenne often exceeding the body in length. Some forms are brilliantly colored while most are pellucid. Perhaps most of the species are found in open lakes, but a number are restricted to swampy localities and others are limited to early spring or late fall and stand in such close relations to other species as to strongly suggest a sort of holer gees like that we have demonstrated in Cyclops. ENTOMOSTRACA OF MINNESOTA. 55 The American literature has been unfortunate in respect to this genus, chiefly because the European species were so imperfectly de- scribed that satisfactory differentiation was impossible. Within the last few years this difficulty has been removed, and the work of De Guerne and Richard has laid the foundation for careful discrimina- tion. It is thought advisable to reproduce the essentials of the de- scriptions of the known species so that other students may have the means of identifying our species, only a small part of which are as yet satisfactorily known. ; KEY TO THE GENUS DIAPTOMUS. I. Male with a hooked ee on the last joint of the right anten- na. . . asiaticus, 56; denticornis, 56. II. Male wid a Feared alate on ste antepenult segment of the right antenna. . . serriconis, 56; wierzejskii, 57; pectinicornis, 57; trybomi, 57; hircus, 57. III. Male with the appendage of the antepenult segment of the antenna prolonged into a curved hook longer than the penultimate seg- Mente Us. s . . @iseni, 58; franciscanus, 58. IV. Male with the a nen dase of ‘ike didispennttiinate joint of the an- tenna straight, and as long as or longer than the penultimate joint. a. The basal joint of the right foot of the fifth pair in the male with an external accessory process. . . . . Salinus, 59; laticeps, 59. b. The basal joint of the right male fifth foot without a process. . minutus, 59; ashlandi, 60; sicilis, 60; baccillifer, 61; shoshone, 61. V. Male with the appendage of the antepenultimate joint of the an- tenna shorter than the penultimate joint. a. The first segment of the abdomen unsymmetrical, with a strong process upon therightside. . signicaudatus, 63; incongruens, 63; gibber, 63. 6. The antepenultimate segment of the antenna of the male witha hyaline appendage along its outer margin. * Inner ramus of the right fifth foot of the male shorter than the basal segment of the externalramus. . zachariasi, 64; leptopus, 64. ** Inner ramus of the right fifth foot of the male longer than the basal segment of the outerramus. . . tatricus, 65; coeruleus, 65. ¢. The antepenultimate segment of the right antenna of the male without a straight lamina. * The process of that segment very shortand obtuse. . . . gracilis, 66. ** The process of the antepenultimate segment of the right male antenna long and pointed. t+ Inner ramus of the left fifth foot of the male shorter than or nearly equal to the basal joint of the outerramus. . orientalis, 66; stagnalis, 66; albuquerquensis, 67; lintoni, 68. tt Inner ramus of the left fifth foot longer tban the basal joint of the outerramus. . . . ._ Siciloides, 69; novamexicanus, 70; sanguineus, 71; minnetonka, 71; armatus, 72. ? ae rae ew we Pn eS eS ares ' eat. mee Al Oy M \ 56 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. VI. Male with the antepenultimate joint of the right antenna not armed with hook or plate. a. Internal ramus of the right male fifth foot longer than the basal joint of the outer ramus. * Internal branch of right fifth foot of the male one-jointed. Oregonensis, 72; pallidus, 73; piscinze, 74; laciniatus, 74. ** Internal branch of the right fifth foot of the male two-jointed. . castor, 74; glacialis, 75; mirus, 75; sancti-patricii, 75. b. Internal ramus of the right fifth foot of the male shorter than the basal joint of the outer ramus. * This internal ramus greatly expanded. . . . . . . Jlilljeborgi, 76. ** Tnner ramus of the right fifth foot of the male not enlarged. + Abdomen asymmetrical. . . roubaui, 76; tyrelli, 76; theeli, 77; lobatus, 77; affinis, 77; amblyodon, 78; mississippiensis, 78. (D. birgei, 79.) Diaptomus asiaticus Uljanin. PCAP EH OX MEG i. Uljanin ’75; De Guerne and Richard ’89. This seems to be a curious depauperate form found by Uljanin in the desert of Kisil-Kum, Siberia. The peculiar form of the fifth feet of the male together with the hook at the extremity of the right male antenna serve to distinguish it. Length of female, 1.76 mm.; of an- tenne, 1.31 mm. Color, red. Diaptomus denticornis Wierzejski. PLATE X, Fia. 4. Sars ’63 (castor); Wierzejski ’82 and ’83 (gracilis), and ’87. This is one of the large species (3.0 mm. long). It was identified by Sars with D. castor. Although originally found in Scandinavia, it appears to occur in suitable stations throughout Europe. The an- tenn are short, scarcely exceeding the third abdominal segment. The last segment of the right antenna of the male hooked, the penul- timate segment with a hyaline plate. The figures illustrate the char- acters of the fifth feet. Diaptomus serricornis Lilljeborg. PLATES VIII, Fria. 14; 1X, Fia. 12. Lillieborg ’88; De Guerne and Richard ’89. A species of moderate size 1.80 mm. long, characterized by the fact that the antepenultimate of the right male antenna bears a projecting plate furnished distally with coarse teeth. The fifth feet of the male are also characteristic. The last thoracic segment bears small spines laterally. The caudal stylets about equal in length the two preceding segments combined. The antennz in the female nearly reach the end of the stylets and are said to be 23-jointed. The species was found in lakes of the Russian tundras. ENTOMOSTRACA OF MINNESOTA. 57 ~ Diaptomus wierzejskii Richard. PLATES VIII, Fia. 4; IX, Fie. 13. Richard ’88; De Guerne and Richard ’89. A rather large species which is obviously very near, if not a variety of D. serricornis. The caudal stylets equal the preceding seg- ment. The antenn do not exceed the second abdominal segment and in the male are armed as described above. The internal rami of the fifth feet of the female are one-jointed. The species has been encoun tered in Spain and Saxony. Length 2.75 mm. Diaptomus pectinicornis Wierzejski. PLATE X, Fie. 3. Wierzejski ’87; De Guerne and Richard ’89. This species can only be separated with difficulty from the other members of this section. Making some allowance for the different positions and distortions assumed under the microscope some diverg- ence is to be expected. The caudal stylets are a little longer than the preceding segment. Antennie reach to thestylets. The dentate plate on the antepenultimate segment of the right male antenna has about fifteen strong teeth on its distal half. 1.8 mm. long. * Diaptomus trybomi Lilljeborg. PLATES VIII, Fie. 17; 1X, Fie. 4; X, Fie. 13. De Guerne and Richard ’89. This is a very peculiar and easily distinguished species. It has but a few minute denticulations at the extremity of the appendage of the antepenult segment of the male antenna, but, in strictness, must fall into the present section. Rather small (1.5 mm.). The last tho- racic segment with a dorsal projection which extends toward the right side. The first abdominal segment in the female also has a large dor- sal process. ‘The caudal stylets areshort. The antennz almost reach the base of the stylets. The form of the feet may be gathered from the figures. Oregon. Diaptomus hireus Brady. PLATE XXXII, Fias. 6-8. Braay ’91. FEMALE.—Seen from above the body is widest in front, thence tapering backwards to the hinder end of the thorax, which is a little wider than the abdomen. The posterior thoracic angles are mucro- nate but not very strongly produced. The anterior antennz reach backwards as far as the posterior end of the thorax. Inner branch of vs ‘ 5 oe AL * wl eS ey f 4 i fa : ie 58 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. fifth foot two-jointed, more than half as long as the first joint of the outer branch, its apex clothed with a fringe of minute cilia; second joint of the outer branch ending in a stout, slightly curved: claw, which is slightly ciliated on the concave margin; last joint bearing at its apex a long, finely ciliated spine and one much smaller seta. MALE.—Antepenultimate joint of the right antenna armed with a plow-share shaped process, which is nearly half as long as the follow- ing joint, and has an obscurely fimbriated free margin. Inner branch of the fifth foot on the left side very small; outer branch slender, end- ing in two subequal finely pectinated sete; the last joint of the pro- topodite has a finger-like hyaline appendage on the inner margin, and there is a Similar but smaller organ in the same position on the right foot. Inner branch of the right fifth foot very small, pyriform, one- jointed, acuminate; terminal claw of the outer branch long, slender, subsigmoid. Length 1.1 mm. * Diaptomus eiseni Lilljeborg. PLATE X, Fie. 11. De Guerne and Richard ’89. One of the largest species known. First segment of abdomen with lateral spines. Caudal stylets short, hairy. Antenne short, reaching the lateral processes of the abdomen. Antepenultimate segment of right male antenna with a hooked process reaching beyond the end of the antenna. Inner ramus of the fifth foot of female obscurely two- jointed. The fifth feet of the male very unequal, inner rami two- jointed; basal joint of the right foot provided with a spiny process. Length 4.0 mm ; male 3.5 mm. This form is about the size of D. stagnalis, but seems quite distinct; it was found at Centreville, Cal. * Diaptomus franciscanus Lilljeborg. PLATE VIII, Fiaes. 12, 16. De Guerne and Richard ’89. A species of moderate size (2.3 mm.). Last segment of the thorax obtuse with minute spines. First segment of abdomen about as long as the rest of the abdomen, spined laterally. Second abdominal seg- ment very short. Caudal stylets short. Antenne reaching to the stylets, 25 jointed. The hook-like process of the antepenultimate joint of the male antenne a little longer than the penultimate joint. The form of the fifth feet chiefly separates this species from Diaptomus similis Herrick. Collected in the vicinity of San Francisco, Cal., by G. Hisen. - ENTOMOSTRACA OF MINNESOTA. 59 Diaptomus salinus Daday. PLATE VIII, Fia. 3. Daday ’85°; De Guerne and Richard ’88! (D. blanchardi), and ’89. This species was found by Daday in Forda, Hungary, and is identi- fied with the form subsequently described by De Guerne and Richard as D. blanchardi. It may be recognized by the sharp spines on the right side of the first and second segments of the abdomen (affording a transition toward Heterocope and Epischura), and also by the pecu- liar armature of the male fifth feet, which have accessory processes -upon the basal joint of the right limb and the second segment of its outer ramus. The apical segment of the outer ramus of the fifth feet of the female are unusually well developed. The antepenultimate segment of the male geniculate antenna has a very long straight pro- cess, longer than the two following segments. Length of female 2.2 mm. The veryshort antenne and saline habitat further distinguish it. Diaptomus laticeps G. O. Sars. Sars ’63; De Guerne and Richard ’&89. This species, which is widely distributed in Europe, has the front considerably dilated. The antenne are as long as the body. The caudal stylets as long as the two preceding combined. The antepe- nultimate of the geniculate antenna has a process shorter than the pe- nultimate segment. The male fifth foot has armature similar to D. salinus. Length 1.5 mm. * Diaptomus minutus Lilljeborg. PLATE VIII, Fie. 9. De Guerne and Richard ’89; Marsh ’92 and ’93. One of the smallest species of the genus, originally taken in Green- land, but widely distributed in the northern regions. Slender, with the greatest width behind the middle. The fourth and fifth thoracic segments fused or more or less distinct in the old, with small mucron- ate lateral lobes. First segment of the abdomen as long as the re- mainder, expanded anteriorly and armed with small spines. Second and third abdominal segments partly fused, the second very short. Caudal stylets twice as long as broad. Antenne 25-jointed, some- what longer than the stylets. Antepenult segment of male antenna with a long slender process, nearly as long as the two following seg- ments and slightly hooked at the tip. The external ramus of the fifth foot of the female is two-jointed, with ashort claw, the inner ramus is small and one jointed. The left fifth foot of the male is much shorter than the right, and its apical segment is armed with a spiny pad and PE eet ess ie PR RE ed eer tet, Tes Ne eros ir ie.) 8 So aban ar Matgtint mx es + a“ > 4 . c aay : f : 60 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. two larger spines; the inner ramus is of moderate size. The inner ra- mus of the outer leg is obsolescent. The accessory spine of the outer ramus is near the middle of its segment. Length 1.0 mm. Marsh finds this form in Green lake and the Great Lakes; it may, therefore, be expected in Lake Superior in Minnesota. * Diaptomus ashlandi Marsh. PLATE VI, Fias. 4-6. Marsh 793. ‘‘A small pelagic species closely resembling D. sicilis Forbes. In form it is slender, hardly to be distinguished from D. sicilis and D. minutus. The first joint of the abdomen in the female is longer than the remaining part of the abdomen, is dilated at the sides and bears two minute lateral spines. The second and third joints are so closely united that the abdomen appears two-jointed. The furcal joints are about twice as long as broad. The antenne reach just beyond the farca. The right antenna of the male is much swollen anterior to the geniculating joint, and bears on the antepenultimate an appendage slightly exceeding in length the penultimate joint. This appendage may be blunt pointed or slightly enlarged at the extremity. The fifth feet of the female are rather slender; the outer ramus is two- jointed. The third joint is represented by two short spines. The inner ramus is one-jointed, a little longer than the first joint of the outer ramus, armed at the tip with two rather long spines. ‘‘The feet of the male are slender. The basal joint of the right foot is about twice as long.as that of the left. The first joint of the outer ramus is a little wider than long. The second joint is wider at the inner than the outer end; the lateral spine is stout, curved, situated near the inner end. The terminal hook is slender and falciform. The inner ramus is slender, one-jointed, and about one-third longer than the first joint of the outer ramus. The left foot extends a little beyond the first joint of the outer ramus of the right. The second joint of the outer ramus has three blunt spines upon its apex and is armed with minute bristles within. The inner ramus is slender, one-jointed, and reaches about half the length of the second joint of the outer ramus. Length of female 0.97 mm.; of male 0.89 mm.’’ This is a pelagic species found in Lake Superior and others of the Great Lakes, and consequently occurs upon the shores of Minnesota. * Diaptomuus sicilis Forbes. PLATES V, Fias. 1-7; XIII, Fie. 18. Herrick ’83 and ’84; De Guerne and Richard ’89; Forbes ’91; Marsh ‘93. The discrepancies respecting this species as described by various authors must be due to heterogenesis. It varies greatly in sizo and armature of the feet. The form is slender and graceful and very like ENTOMOSTRACA OF MINNESOTA. 61 D. pallidus, from which it differs in possessing a hook on the right male antenne. The antenne exceed the caudal sete and are very slender; that of the male on the right side bears a curved plate or hook which in my specimens is decidedly shorter than the following joint, though said to be equal to it by De Guerne and Richard. The fifth feet of the female resemble those of pallidus. The inner rami of the male fifth feet are two jointed in the type, but both Marsh and I find forms with one-jointed rami. The terminal claw of the right foot is long and geniculately curved, the accessory spine of the pre- ceding segment is near the distal one-third, the inner ramus is (in our ‘form) quite slender, longer than the basal segment of the outer ramus. The terminal joint of the left foot is rounded and ciliated, as well as furnished with two spines. Length of larger forms 1.4 mm., male considerably less. Our small form is 1.1 mm. long and may prove a subspecies, though agreeing with Marsh’s figures. Compare also D. siciloides, the western representative of this small form. Diaptomus baccillifer Koelbel. PLATE X, Fia. 2. . Wierzejski ’82 (D. gracilis var. d and b); Koelbel ’85; Wierzejski ’87 (D. mon- tanus); De Guerne and Richard ’89. A small species encountered in high latitudes and altitudes of the old world, Siberia and the Alps being the chief stations, is not well distinguished from its allies. The antenne reach the stylets, and in the male the geniculate antenna has a strong process on the ante- penult joint. The internal rami of the fifth feet are more or less dis- tinctly two-jointed, being very short in the female. The inner ramus of the left foot in the male is fused with the preceding segment, and near its base is aspine. The outer ramus of the same foot is forcipate. Length 1.0 to 1.5 mm. * Diaptomus shoshone Forbes. PLATE V, Fia. 11. Forbes 793. ‘‘A very large and robust species. Thorax broadest in front, across the maxille, tapering gradually, with little convexity to the posterior third. In the female the angle of the last segment is bifid, both projecting points being minutely spinose at the tip. The first segment of the abdomen is laterally expanded; the expansion of the left side with a minute spine at the apex behind; that on the right produced at the same point into a small, rounded tubercle, 0.03 mm. in length, about as broad as long, making this first segment somewhat unsymmetrical.”? ‘‘Egg mass very large, obovate (narrowest for- ward). Right antenna of male robust, the last two joints without special appendages, antepenultimate with a long inarticulate process at its outer apex, extending beyond the tip of the penultimate and to OT ee Oe a WP ites ale EA Mg Ee a etl ie es PRIM tel . ak V FT eee, F Se x. 62 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. the middle of the last segment. The margins of this process are smooth, but it is broad and emarginate at the tip. The fifth pair of legs of the male resemble the corresponding appendages of D. stagnalis, but differ notably in detail. The left ramus of the rigkt leg is borne at the inner terminal angle of the second joint, is longer than the joint following, is armed at the apex with a few small acute spines, and bears upon its outer margin, near the tip, a broad fascicle of delicate hairs. The basal joint of the outer ramus is two-thirds the length of the second joint of the peduncle, and without hairs or spines of any description. The second joint of this ramus is about equal in length to the second joint of the peduncle, and bears at its outer mar- gin, close to the tip, the usual stout seta, which is two-thirds as long as the joint to which it is attached. The terminal claw is not regu- larly curved, but is nearly straight for the basal three-fourths. The left leg is bi-ramose, the inner ramus straight, slender, extending about to the middle of the second joint of the outer, and armed at its tip. The second joint of this ramus is as long as the first, if measured from the tip of the apical spine. This spine, seen from behind, is stout, conical, rather blunt, and has opposed to it within, projecting from the inner angle of the segment, a stout, curved seta, slightly plumose on its distal half. Between these, but more closely applied to the outer spine, is a hemispherical cushion-like elevation, set with small, short spinules. On the basal half of the inner margin of this terminal segment is also a much larger hemispherical cushion, but with longer and more slender hairs, while the terminal half of the in- ner margin of the segment preceding is also moderately inflated and covered with delicate hairs. The antennz of the female are 25 jointed, as usual, and reach to the base of the abdomen. The legs of the fifth pair closely resemble those of stagnalis, but have the terminal set of the inner ramus much less developed. This ramus is a little shorter than the basal joint of the outer ramus, and about half its diameter. It bears at its tip two stout sete equaling the ramus itself in length, plumose under a high power, and has, in addition at its inner tip and on the margins adjacent, a patch of delicate hairs and spines. The second joint of the outer ramus is as long as the first, if measured from the tip of its terminal claw. The latter is nearly straight, very slightly recurved. This joint bears a single spine at its outer distal angle, just within which is the rudiment of the third segment of the ramus, which bears two spines similar to the above, the inner of which is the longer, the outer itself being longer than the adjacent spine of the second joint. Adults of both sexes are blood-red throughout, except the egg sac of the female, which is purple.’’ Length of female, in- cluding sete, 3.1 mm.; male, somewhat smaller. In various lakes in Yellowstone Park. ~ =e 4s, S ees 1 yg co ew wt She i. ie ee ¢ sl ae Ree ee eee Fn a CAR Oe eth PROPOR Coe a a AP ae “eit ENTOMOSTRACA OF MINNESOTA. 63 * Diaptomus signicaudatus Lilljeborg. PLATES VIII, Fie. 13; IX, Fie. 10. De Guerne and Richard ’89. A small species found at great altitudes in the Sierra Nevada Mountains of California and forming an obvious transition toward Epischura. Form rather robust, greatest width at the second segment. Last two segments of the thorax confluent, projecting into lateral lobes bearing small teeth. The fourth thoracic segment with a slight dorsal gibbosity. First abdominal segment expanded and spined anteriorly, and bearing a large retrorse process on the right side posteriorly. Second segment short. Caudal stylets about half again as long as wide. Antenne 25-jointed, extending little beyond the stylets. An- tepenult segment of the right male antenna with a small hook. Fifth foot in the female with one-jointed inner ramus as long as the basal joint of the outer ramus. The terminal segment of the outer ramus is obsolescent. The external ramus of the right foot of the male bears a hyaline lamina on the inner aspect of the basal segment. Second segment more than twice as long as the preceding. Claws simply arcuate. Accessory spine nearer the end than the base of the second segment. Inner ramus wide and acute, shorter than the basal segment of the outer ramus. The left foot has a slender inner ramus, longer than the basal segment of the outer, whose apical joint is pilose and armed with two spines. Length of female 1.5 mm.; of male 1.3 mm. Diaptomus incongruens Poppe. PLATE VIII, Fia. 6. Poppe ’88; De Guerne and Richard ’89. A Chinese species of moderate size, characterized by the fact that the projecting angles of the last thoracic segment are dissimilar on the two sides and the possession of a broad mucronate process on the right side of the first abdominal segment. The antennz extend far beyond the stylets. The antepenult joint of the right male antenna bears a hyaline lamella ending distally in a small hook. The fifth foot of the female has a one jointed inner ramus as long as the basal joint of the outer ramus. The apical joint is distinct and the claw serrate. The inner ramus of the right foot of the male is one-jointed and that of the left foot two-jointed. The terminal segment of the outer ramus of the left foot has two spines apically and a ciliated plate within. Length of female 1.4 mm. Diaptomus gibber Poppe. PLATE VIII, Fie. 1. De Guerne and Richard ’89. A decidedly unique form from Brazil. The last thoracic segment forms on either side a bispinose process, the two being dissimilar. The first segment of the abdomen is expanded proximad and bears on Fee) 8 ee ea A und ig: ya s3 *% - 64 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. the right side distally a broad blunt process. Antennz reaching the caudal sete; that of the male on the right side bearing a lamella and hook on theantepenult segment. Inner rami of fifth feet in the female two-jointed, outer ramus three-jointed. The inner rami of the fifth feet of the male are curiously modified, and we must refer to the figures. Diaptomus zachariasi Poppe. PLATE X, Fie. 6. Poppe ’86; De Guerne and Richard ’89. A species closely resembling D, leptopus and found in Silesia. While the last segment of the abdomen is not dilated it is ornamented with two spines. The inner ramus of the fifth feet of the female is two- jointed and armed at the apex with three spines, and is somewhat longer than the basal joint of the outer ramus. At the base of the claw of the outer ramus isastrong tooth. The apical segment is distinct and bears two spines. The figures of the male foot are not entirely satisfactory, but the inner ramus of the right leg is said to be rudimentary, short and two-jointed, while that of the left leg is one-jointed but quite Jong. The apical joint of the left foot is forcipate. The antepenult segment of the male antenna has a hyaline plate which is scarcely hooked dis- tally. Length of female 1.8mm. Like our D. leptopus this species is brilliantly but variously colored. * Diaptomus leptopus Forbes. 1882. PLATES IT; IX, Fie. 9. Forbes ’82; Herrick ’84 (D. longicornis var. leptopus); De Guerne and Richard ’89; Marsh ’93. This species, which is one of the commonest in small lakes in Min- nesota, is widely distributed in the Mississippi Valley. While not large it is generally ornamented with brilliant coloration bands, of which the purplish suffusion of the tip of the antenne and abdomen are most constant. Marsh found it of a brownish red color much as D. sanguineus. We find it during the summer quite pellucid except for the purple markings. The body is stout with the head and last two thoracic segments fused. The last thoracic bears on either side one or two small spines. The abdomen is short, the last two segments being fused; the first segment bears a small lateral spine on either side. The female antennze do not extend to the end of the caudal set and their spines are short. The right male antenne is strongly geniculate and spined. The antepenultimate segment bears only a very inconspic- uous hyaline lamina but no hook or process as stated by Forbes and by De Guerne and Richard. The fifth foot of the female is short, with an inner ramus scarcely shorter than the antepenultimate segment of the outer ramus and bearing at the tip two subequal spines and a cil- ENTOMOSTRACA OF MINNESOTA. 65 iated process. Wedo not find in this species that the claw of the penultimate segment of the outer ramus is denticulate, though in some stages or forms it may be. The apical segment is obsolescent and bears two unequal spines. De Guerne and Richard figure an accessory spine at the base of the apical segment. There is occasionally a slight ten- dency for the inner ramus to appear obscurely two-jointed. The male feet of the fifth pair are very long. The inner rami are both rather long (longer than the segment of the outer ramus opposite which they stand), one-jointed, and slightly ciliated apically. The terminal claw of the right foot is short and slightly curved and denticulate toward the apex interiorly. The preceding segment has a short accessory spine. The segment bearing the two rami has a short spine laterally and is bristly exteriorly. The terminal segment of the outer ramus bears two spines and a few cilia, while the penultimate segment has a ciliated process inwardly near its apex. The armature of the third and fourth feet is similar, the apical segment of the outer ramus bear- ing an external short spine, one long spine and two sete at the tip, and three sete internally. Length of female 1.5 to 1.7 mm.; of male 1.4 mm. Diaptomus tatricus Wierzejski. PLATE X, Fie. 8. Wierzejski ’82 (lacinulatus), and ’83; De Guerne and Richard ’89. A large, stout form, with antenne scarcely exceeding the thorax nd the last segment of the latter produced into a large spindle-shaped, protuberance. The antepenult joint of the male antenna with a hya- line lamina. Inner ramus of fifth feet of the female short, obscurely two-jointed; those of the male curved. A tooth is found on the mid- dle of the inner aspect of the basal segment of the left foot, and the apical segment of the outer ramus is forcipate. Length 2.1 mm. Color carmine red. Diaptomus coeruleus Fischer. PLATE IX, Fic. 7. ‘& S. Fischer ’53 (Cyclopsina ccerulea); Lubbock ’63; Poggenpol ’74; Uljanin ’74; De Guerne and Richard ’89. This widely distributed specics has been very frequently con- founded with D. castor, than which it is rather smaller and from which if differs in possessing a lamina on the antepenultimate segment of the male antenna. The antenne reach the candal stylets. The apical Segment of the outer ramus of the fifth foot of the female is well de- veloped and its inner spine is almost as long as the claw ofthe penulti- mate joint. The inner ramus is two-jointed and longer than the basal joint of the outer ramus. The inner rami of the male feet are one- jointed. Length1.8 mm. Reape 4 Eo APRNs Se Cokie ag ie ar ee iS A sea 9 a rp akin MG aS ma si X aa ~ R ‘ ; ° 4 0 ae hy Ph walt ake NT Fad ase ae oy rs °. 50S Veen ede 2 eae b. Fifth foot two-jointed. sees aah asa ko eh ae a in iM Se ak ENTOMOSTRACA OF MINNESOTA. 89 * First joint of the fifth foot broad. . . viridis, 90; americanus, 91; ingens, 92; vernalis, 92; robustus, 93; parcus, 93; brevispinosus, 95; uniangulatus, ¢6; leuckarti, 96; secourfieldi, 98; oithonoides, 98; dybowskii, 99; bisetosus, 99. ** First joint of the fifth foot longer than wide. {+ Terminal segment of the fifth foot with one long seta and Oneshortspine. . . . . . Strenuus, 99; lacustris, 101. tt Terminal segment of the fifth foot with two rather long sete, pulchellus, 101; minnilus, 103; forbesi, 104. ttt Terminal segment of the fifth foot with threesete. . Signatus 105; var. coronatus, 106; var. tenuicornis, 106. III. Antenne 16-jointed, languidus, 107; modestus, 108; capilliferus, 109; ae Aubonne 14-lointed of a a tk eo. eo. msignis, 110: VY. Antenne 12-jointed. a. Fifth foot one-jointed. . . . serrulatus, 111; var. elegans, 112. macrurus, 113; prasinus, 113; fluviatilis, 114. b. Fifth foot two-jointed. . . . cGapillatus, 115; crassicaudis, 115; varicans, 116. VI. Antenne Ll-jointed. . . gracilis, 117; diaphanus, 117; affinis, 117; bicolor, 118. VII. Antenne 10-jointed. Tee eos eee ee DR ALerAatuss 1:20) VIII. Antenne eight-jointed. . . ..... =... . .*fimbriatus, 121. IX. Antenne six-jointed. .... . 3 . . . equoreus, 122. The forms which have been boponked with is -jointed antennze may not necessarily be representatives of a single species but may be spor- adie instances of reduplication in the antennal segments on the part of various 17-jointed forms. Cyclops elongatus Claus, the only named species with 18-jointed antenne, is confidently identified with C ver- nalis Fischer, by Schmeil, nevertheless Claus’ description is as follows: ‘*Length of body 2.5 mm., elongate, gradually narrowed toward the end. The anterior antennz 18 jointed, differing from the 17-jointed type by the separation of the seventh joint into two; they do not ex- tend far beyond the first segment of the cephalothorax. The fifth ab- dominal segment is strongly toothed. Rudimentary foot two-jointed, with relatively small basal joint and elongate terminal one, on whose apex is one long and one short seta. The stylets are longer than the two last abdominal segments, with relatively short sete, whose rel- ative size is nearly like those of ©. cuspidatus.”’ This species is reported by Cragin from near Cambridge, but has been seen by no other observer except the describer. * Cyclops ater Herrick. PLATES VI, Fias. 11, 12; XIJ, Fias. 9-12; X XI, Fias. 13-15, 17, 18. Herrick ’82, ’84, ’87; Turner ’92. Cephalothorax very large and broadly oval and usually conspicu- ously colored. Antenne as long as the cephalothorax (1.2 mm.), Ot eof GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. slender, tapering toward the end; formula* —~-~——-~—_~-__=~~ ——-—; last three segments not elongate, the last being furnished with an unserrated, hyaline knife-like ridge as in (. tenuicornis. Anten- nules much as in C. tenuicornis. Maxillipedes rather large. Fifth foot one-jointed, armed with three subequal spines. Abdomen very short, especially the last segment. Stylets rather more than twice as long as wide, the three inner sete long and pectinate but none very long, external seta short, lateral seta near the end of the stylet. Fourth foot with the following armature of apical joints: tex. 2 spines. ex. 1 seta. Outer ramus | ap. 1spine, 1 seta. Inner ramus | ap. 2spines. in. 4 sete. in. 2 setz. The sete are all short and stout. Color deep blue or gray; young with a deep band of color crossing the thorax near the middle. Ovisacs pale, rather small. Length 2.1 mm. This, our most char- acteristic American species, is sparingly but widely distributed, at least, throughout the Mississippi Valley. Cyclops viridis Jurine. 1820. PRATHER V; Subspecies europzeus Herrick. Var. a.—Koch ’35 (C. vulgaris); Fischer ’51; Claus ’57 and ’63 (C. brevicornis); Sars 63; Lubbock ’63(C. brevicornis); Heller ’70 (C. brevicornis); Fric’721 (C. brevicornis) ; UJjanin ’75; Hoek ’76 (C. brevicornis); Rehberg ’80!; Daday ’85°; Vosseler ’86; Sostaric ’88; Thallwitz ’90; Lande ’90; Schmeil ’91; Richard ’91; Schmeil ’92. Var. b.—Claus ’57 (C. gigas); Sars ’63 (C. gigas); Fric ’721 (C. gigas); Brady ’78 (C. gigas); Sostaric (C. viridis var. gigas); Rehberg ’80'. Subspecies americanus Marsh. Var. a.—Cragin ’83 (C. viridis); Herrick ’83 (C. parcus) and ’84 (C. brevicornis) (passim); Marsh ’93 (C. americanus); Turner ’92 (C. viridis). Var. b.—Herrick ’82 and ’83 (C. ingens). If we accept Rehberg’s suggestion that the two European species, C. brevicornis and C. gigas, are but forms of the same species, we are driven to a somewhat anomalous arrangement of the synonomy, though, when so arranged, it expresses a not unusual parallel devel- opment of species on the two sides of the Atlantic. As the writer stated in 1882, the American representatives of this species differ in several minor points from the European and a new name was given. Later, in deference to Rehberg’s discovery of greater latitude of varia- * The characters in these formu’ are used to indicate the relative length of the joints, from base to tip, as follows: ~, short; =, medium; —, long. fex. exterior; ap.—apical; in.—interior aspect. ENTOMOSTRACA OF MINNESOTA. 91 tion than once supposed, C. ingens was united with C. gigas as an un- named variety of C. viridis (Herrick’84, p. 145). The preimago stage is similar to that of gigas, and this fact made the union seem more legitimate. Still later Marsh, without recognizing the varietal differ- ences and having only the smaller form before him, erects for it a new species, C. americanus. Of course, if this is to include the whole assemblage representing C. viridis in America, the name C. ingens is prior. If not, the later name may be revived for the form correspond- ing to C. gigas of Europe. To judge from the figures in Claus’ Das Genus Cyclops, the European form is subject to a very wide range of variation, for C. furcifer, after- wards regarded as a simple varietal form of C. brevicaudatus, has the stylets and antennz greatly elongated. Unfortunately the details of the armature of the feet are not given by Claus or most of the authors following him. Var.a. *Cyclops americanus Marsh. Pa AT OEY Subspecies Americanus Marsh. We quote Marsh’s description entire: ‘‘Cephalothorax oval, the first segment being about half its total length. Antenne 17-jointed, about as long as the first cephalathoracic segment. Abdomen rather slender, the last segment armed on its posterior border with small spines, All the abdominal segments in immature individuals are strongly pectinate posteriorly. Furca about three times as Jong as its average breadth, the lateral spine sit- uated well towards the end. The first and fourth terminal sete are short, slender and plumose, nearly equal in length. Of the internal setce, the outer is a little more than three-fourths of the length of the inner. The armature of the terminal joints of the swimming feet is as follows: First Foor. ex. 3 spines. ex. 1 seta. Outer ramus | 2 sete. Inner ramus {i 1 spine, 1 seta. in. 2 sete. in. 3 sete. SECOND AND THIRD FEET. ex. 3 spines. 1 seta. Outer ramus {se 1 spine, 1 seta. Inner ramus | 1 spine, 1 seta. in. 3 sete. 1 3 sete. FouRrtTH Foor. ex. 3 spines. ex. 1 seta. Outer ramus {sp 1 spine, 1 seta. Inner ramus | 2 spines. in. 3 sete. in. 2 sete. ‘‘Fifth foot two-jointed, basal joint very broad, armed with one seta. Terminal joint armed with a seta and a blunt spine. Length 1.2 mm.”’ aici 92 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. The points of difference consist in the fact that the antenn# are shorter than European viridis, reaching only to the second instead of to the third thoracic segment, and that the armature of fourth feet are very unlike the figures and descriptions of European authors. Brady is the only author who figures these parts, and these figures are evi- dently careless, for the antenne on the same plate have a supernu- merary joint. We have examined a number of specimens of this spe- cies from distant parts of the United States, and find, with Marsh, the armature constant or but slightly variable. The proportions of the apical spines of the inner ramus of the fourth foot are the reverse of those given in his figure. The size varies remarkably, passing into the large variety. 1.4 mm. isan an average measurement exclusive of sete. ; r Var. b. *Cyclops ingens Herrick. PLATE XXV, Fies. 1-8. This is the largest form yet encountered in America and is rarely seen. It isasimple exaggeration of the last, there being no obvious distinctions except the size. It is occasionally over 4.0 mm. long in- cluding the sete or about 3.0 mm. excluding them. It may be noticed that the males of this group have a well-devel- oped sixth foot. The antenne are strongly modified and amply spined, as shown in the figure. A series of hyaline plates near the joint are well developed. *Cyclops vernalis Fischer. (Fide Schmeil.) Fischer 53; Sars ’63 (C. lucidulus); Claus’63 (C. elongatus); Heller ’70 (C. elongatus); Rehberg ’80! (C. elongatus and C. lucidulus); Cragin ’83 (C. elongatus); Herrick | 84 (C. elongatus and lucidulus); Daday ’85° (C. lucidulus); Sostaric ’88 (C. luci- dulus); Schmeil ’91 (C. elongatus) and ’92; Richard ’91; Brady ’91(C. elongatus). We cannot, of course, enter the perplexing synonomy which has been very carefully studied by Schmeil, and we hope that it may now be considered settled. The not quite unexpected discovery that a 17-jointed species may, under certain conditions, become 18-jointed rests on the same kind of evidence which Schmeil rejects in respect to our own statements in the case of other species, and offers a certain probability in favor of the frequent occurrence of imperfectly mature but oviparous females, which he rejects without making the necesary investigation by which he might easily have convinced himself of its reality. However, we are fain to accept the evidence that C. elongatus Claus is but a ‘‘post imago”’ of ©. lucidulus Sars. Still it is not to be forgotten that other species may sporadically develop 18 jointed an- tenne and then might lay claim to be considered C. elongatus. + Se ¥ y ‘ Py 3 f ly . 7 * Le sae ae +y. wo i. : Re ee mM P 6d ee sh Pie li ree ert oe eh salt “) . . ree ey ae ee | ENTOMOSTRACA OF MINNESOTA. 93 Cephalothorax rather long, tapering caudad, fourth and fifth seg- ments somewhat produced. Abdomen more than half as long as thorax, first segment as long as the remainder. Stylets as long as the two preceding segments plus half the next. Median apical sete nearly equal, as are the outer and inner, which are both short. The antenne are shorter than the first thoracic segment, either 17-jointed or 18- jointed by the subdivision of the seventh joint. Schmeil claims to have found some in which the right antenna is in one condition and the left in another. Fifth foot two-jointed, basal segment short, broad, bearing a plumose hair; second joint small, cylindrical, armed with a short spine and a plumose seta. Receptaculum opening transversely narrowly elliptical. Length 1.2 to 1.7 mm. Cyclops robustus Sars. I simply quote the original description: ‘‘Corpus breve et robustum depressiusculum, segmento 1 mo lato et antice «que rotundato, ceteris ad latera sat exstantibus, ultimo quam segmento 1 mo abdominali multo latiore. Rami caudales vix divergentes longitudinem segmentorum anteceden- tium 2 superantes setis apicalibus fortibus et fere aculeiformibus, intermediarum in- teriore quam exteriore multo longiore longitudinem abdominis fere equante versus medium sparsim dein dense ciliata, ceteris duabus brevissimis et fere ejusdem longi- tudinis. Antenne 1 mi paris 17 articulate, breves et crassee segmento 1 mo corporis breviores. Articulus ultimus rami exterioris pedum natatoriorum latus extus aculeis 3, intus setis 4 instructus; seta marginis exterioris articuli ultimi rami interioris in pedibus 2di—4ti paris in aculeum fortem conformata; aculeique apicales 2 ejusdem articuli in pari 4to subequales. Pedum 5ti paris articulus ultimus parvus intus aculeo brevissimo et rudimentari armatus. Sacci oviferi ovales abdomini appressi. Longit. circit. 14 mm.”’ * Cyclops parcus Herrick. PLATES XX, Fias. 12-15; XXI, Fie. 22; XXII, Fie. 8; XXXIV, Fies. 1-8. Herrick ’&2 and ’84; Marsh ’93. This species, which is very near to C. vernalis and ©. viridis, has more superficial resemblances to C. pulchellus, which it also resembles in the form of the swimming feet, occurs in small and stagnant pools. The antenne are shorter than or about as long as the first thoracic segment, the last two segments of which are acute. The antennules are rather short. Labrum narrow, projecting below into obtuse angles, cutting edge with nine small teeth. The terminal joint of the larger branch of the maxilliped bears four hairs. The second joint has a moderately large dactyl, the movable finger of which is small and Sparsely spiny, the immovable finger is ornamented by an oblique series of blunt prominences and a small seta at its base. The arma- ture of the swimming feet is as follows: A OS a ae Ae yA eS 4, Ps er EY OP ee Oa be 5. pat ha PT we Pa eek OR A Be es PRR oe ete IG Se ne ee eR TERNS og de oe i ; ; : - : Rite5 55-5. whe DU SO ar ee Re CUM! Perl) Ha ts eee ae a ea 94 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. FIRST FEET. ex. 2 spines. ex. 1 seta. Outer ramus 4 ap. 2 sete. Inner ramus jap. 1 spine, 1 seta. in. 2 sete. in. 3 sete. SECOND FEET. ex. 2 spines. ex. 1 seta. Outer ramus < ap. 1 spine, 1 seta. Inner ramus ; ap. 1 spine, 1 seta. in. 3 sete. in. 3 sete. FOURTH FSET. ex. 2 spines. ex. 1 seta. Outer ramus jap. 1 spine, 1 seta. Inner ramus ; ap. 2 equal spines. in. 3 sete. in. 2 sete. The fifth foot is two-jointed, the basal joint being short, broad, and armed with one seta, while the apical segment is short, fusiform with a long seta and short spine. The foot is very like that of ©. viridis, but the basal joint is smaller. The abdomen is rather slender, the first joint being rather longer than the remaining joint exclusive of the stylets. The latter in the average form are rather short and the lateral seta is over one-fifth their length from the apex. The outer apical seta is three-fourths the length of the inner. The inner median seta considerably longer than the outer. In addition to the ordinary form with short stylets there are frequently found others which have the stylets considerably elongate. Such a form is figured in Plate XXXIIT. In this case the stylets are six times as long as wide and equal in length the last two and half of the next abdominal segments. The small lateral spine is more than a fourth the length from the end, and there is a slight unserrated offset at the basal one-fourth exter- nally. The inner seta is nearly as long as the stylet, the outer two- thirds as long. The inner median seta is three times as long as the stylet, and the outer is but twice as long as the stylet. The antenne in this form are about as long asthe first segment, which forms nearly half the length of the thorax. The abdomen without the stylets is half the length of the thorax. The form of the receptaculum is transversely oval, very similar in fact to C. vernalis. Unfortunately the printer in the preceding edi- tion made the description of Plate 24 so read that the figure of this structure was credited to C. adolescens. Length1.4to1.5 mm. The following measurements of the elongate form are given to illustrate the proportions: Length 1.37 mm., thorax 0.85 mm., first segment 0.41 mm., abdomen (exclusive of stylets) 0.41 mm., stylets 0.19 mm., antennz 0.45 mm., longest seta 0.50 mm. It is possible that the elongate form, which is found in association with the type, is to be regarded as a post-imago. There is danger of confusing this form with C. brevispinosus Herrick, and it is not certain that this has not already happened to some extent. EN'TOMOSTRACA OF MINNESOTA. . 95 *Cyclops brevispinosus Herrick. 1884. PLATES XXIII, Fias. 1-4; XXIV, Fies. 7-12. This species may be regarded as the pelagic representative of C. parcus. In the original description the following differences were noted. The form is more slender and the stylets are greatly elongated, the outer caudal seta is reduced to a short ciliate spine, and the fourth foot is differently armed and the receptaculum is somewhat different in form. Marsh says that one might infer from my statement that the arma- ture of the swimming feet is the same as in C. parcus, but how this could be possible in the face of the plain statement of difference and figure of the fourth foot it is hard to see. The first segment of the compact thorax is half its entire length and the antennz are rather shorter. The abdomen is rather slender and tapering. The stylets are 4.5 times as long as wide, and the small lateral seta is more than two-thirds its length from the base. The outer terminal seta is transformed into a very short stout serrate spine, shorter than the inner seta and one-third as long as the stylets. The outer median seta is less than three times as long as the stylet and is naked for more than half its length, when it is suddenly narrowed and very closely pectinate to the end. The inner median seta is almost exactly three times as long as the stylet, and is sparsely pecti- nate for its middle third and closely so for its apical third. The armature of the feet is as follows: First Foor. ex. 3 spines. ex. 1 seta. Outer ramus | 2 sete. Inner ramus; ap. 1 spine, 1 seta. in. 2 sete. in. 3 sete. SECOND Foor. ex. 3 spines. ex. 1 seta. Outer ramus {8 1 spine, 1 seta. Inner ramus {8 1 spine, 1 seta. in. 3 sete. in. 3 sete. THIRD Foot. ex. 3 spines. ex. 1 spine. Outer ramus ; ap. 1 spine, 1 seta. Inner ramus; ap. 2 spines. in. 3 sete. in. 3 sete. FouRTH Foot. ex. 3 spines. ex. 1 spine. Outer ramus { ap. 1 spine, 1 seta. Inner ramus; ap. 2 spines. in. 3 sete. in. 2 sete. The basal segment of the fifth foot is little expanded and bears one seta while the short second joint has an apical seta and a small lateral extemal epine.< hormula, torvantennee, 2... Ce ee Antennules rather short. Length 1.0mm. Marsh suggests that this may be a pelagic form of (. viridis var. Americanus, in which case C. parcus would become a variety of the same species. 96 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. Cyclops uniangulatus Cragin. Cragin ’88; Herrick ’84. Cragin was not conversant with the description of C. parcus, with which his description agrees save in one point. It differs from C. parcus in having three inner sete on the terminal joint of the outer ramus of the first foot. It would be officious to suggest a possible oversight here, but C. parcus has only two in type specimens (though in all this group the corresponding ramus of the second foot has three sete), so that at present the two must be kept distinct. * Cyclops leuckarti Claus. Puates XVI; XVIII, Fias. 1, A-J; XXIV, Fies. 2-6. Claus ’57 and ’63; Sars ’63; Poggenpol ’74 (simplex); Uljanin ’75 (tenuicornis); Hoek 78 (leeuwenheekii); Herrick ’83 (tenuissimus) and ’84 (simplex and leuckarti); Daday ’85 (simplex, pectinatus, and leuckarti); Vosseler ’86 (simplex); Herrick ’87 (simplex); Thallwitz ’90 (simplex); Lande ’90 (simplex); Schmeil ’91 and ’92; Richard ’91; Forbes ’91 (edax); Brady ’91 (scourfieldi); Marsh ’92. ‘‘DESCRIPTION OF THE FEMALE: The form is very slender, an average individual measuring between 0.95 and 1.0 mm. exclusive of the caudal sete. The following detailed measurements of a specimen measuring 0.976 mm. will serve to exhibit the proportions of the parts: First thoracic segment 0.30 mm., second segment 0.08 mm., third seg- ment 0.08 mm., fourth segment 0.056 mm., fifth segment 0.024 mm.; first (apparent) abdominal segment: 0.16 mm., second segment 0.08 mm., third segment 0.048 mm.; caudal stylets 0.088 mm., outer seta 0.08 mm., outer median 0.30 mm., inner median 0.46 mm., inner 0.20 min., dorsal 0.06 mm.; the lateral seta is 0.036 mm. from the end. The antennie reach nearly to the base of the thorax when reflexed, and are quite strong. They resemble those of C. tenwicornis in several par- ticulars, but since it is desirable to distinguish this species with the greatest possible accuracy, the following numbers are given to express the relative length of the several segments, beginning with the first: 120, 25, 33, 410, 57, 64, 711, 95, 95, 105, 117; 127) 189) 146, 1510; 1619, 1714. The fourth, eleventh, fourteenth and fifteenth segments bear the longest sete. The last two segments are armed with a knife-like ridge similar to that found in C. tenwicornis. This ridge is serrulated on the last segment, and near the end is cut by a deep incision so that the terminal part is like a hook notched upon its convex outer part. The antennules are slender and but moderately spinous, the first three segments being almost exactly equal (0.06 mm.), while the ter- minal segment is as long as the basal segment of the antenne (0.08 mm.). The labrum is armed with thirteen small teeth. The larger maxilliped is pearled on the posterior margin of its largest segment. The armature of the terminal joints of the feet is as follows: i hs bee 2h SE ee Pe oe mh ENTOMOSTRACA OF MINNESOTA. 97 First Foot. B ex. 2 spines. ex. 1 seta. Outer ramus jap. 2 sete. Inner ramus ; ap. 1 spine, 1 seta. in. 2 sete. in. 3 se!e. SECOND AND THIRD FEET. ex. 2 spines. ex. 1 seta. Outer ramus 4 ap. 1 spine, 1 seta. Inner ramus ; ap. 1 spine, 1 seta. in. 3 sete. in. 3 sete. FourTH Foor. ex. 2 spines. ex. 1 seta. Outer ramus {8 1 spine, 1 seta. Inner ramus {8 2 spines. in. 3 sete. in. 2 sete. “The fifth foot is two jointed, the basal joint is short and bears a tubercle carrying a seta 0.06 mm. long, the terminal segment is terete and bears a spine 0.10 mm. long apically ana another as long upon the middle of its inner side. The cement gland is of peculiar shape, resembling that of C. parcus exactly. The last segment of the abdomen is spiny upon the posterior margin above. The color is usually pale, but may be ornamented with bluish suffusions. ‘‘Though closely allied with the species in America identified with Sars’ C. oithonoides there can be no doubt that two forms occur, this one being nearly exactly like the species described by Hoeck as C. leeuwenhekii. 'The description and drawings are given asa basis upon which to distinguish other allied species. The form from the Southern States originally called C. tenwissimus is probably this species, though possibly distinct.’’ I have quoted our own original descriptions, correcting misprints in the armature of the feet, which was, however, correctly given in the figures. Schmeil’s figure of the armature of the antennez is faulty in not representing the teeth upon the lamina although the excision is clearly shown. The form described in the previous edition as C. oithonoides Sars, has not been re-examined and I am inclined to believe that it is but a small pelagic form or variety of the typical C. leuckarti. Cyclops oitho- noides is essentially a brackish water form and with its variety hyalina Rehberg, and C. dybowskii Schmeil, constitutes a very close group whose members are quite variable and occur under such conditions as to lead one to suppose that they constitute a compound specific group whose members have not yet attained their autonomy. The original description of the American form is appended: ‘“‘This most interesting species occurs under peculiar circumstances. It is perhaps the rarest member of the genus, and seems, beyond a doubt, nocturnal in its habits. It was first found by Sars in saline water, and named, on account of its slender form, from the marine Oithona. A similar species which, though about half as large, is hardly distinct, was found by Rehberg near Bremen. Rehberg men- ee : Ce Et LR TES RPT eRe LT ST ORE, aan Oe erent Men Sc. at Vea teen nna ~ ra me “oe y Lo 25 ee Soe 98 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. tions particularly that it was found oftener at night than during the day. In America a similar species was described from near Paducah, ~ Ky., under the name C. tenuissimus; but the possibility of identity with the Scandinavian species seemed excluded by the habitat. A gathering taken at night from one of the lakes near Minneapolis con- tained a few specimens of similar characters, and there no longer | seems to be a doubt of the identity or very close relation between these forms. ‘“‘The antenne are longer than described for C. tenuissimus, nearly equalling the thorax. The last joint of the antenne is short, but the toothed character was not noted. The fifth feet are small, the spines are very long and slender. The margins of the abdominal segments are irregularly toothed. The species will be confused with no other. It is marked with blue in spots. Length 0.5 to 1.0 mm.”’ Cyclops scourfieldi Brady. Brady ’91. It is very difficult to determine whether we have in this species a variety of C. leuckarti or a distinct species. Brady identifies it with Sars’ C. leuckarti, which is regarded as distinct from Claus’ (. leuckarti. Schmeil has decided, after examination of Sars’ specimens, that they belong to C. leuckarti Claus, and are the same as C. simplex of other authors. Under these circumstances there would seem to be no rea- son for hesitating in referring C. scourfieldi to C. leuckarti were it not that the figure of the fourth foot given by Brady differs in armature from that of Schmeil, and Brady fails to remark the striking armature of the last joint of the antenna. If Schmeil is correct in saying that the pearling or crenulation of the posterior margin of the maxilliped is diagnostic of C. leuckarti, the matter would be settled at once, for Brady clearly figures it. On the whole, we incline to believe that Brady’s figure incorrectly shows a seta where there should be a spine at the apex of the outer ramus of the fourth foot and that he has over- looked the hyaline plate on the antenna. He says, however, ‘‘the character which, so far as I know, distinguishes at once C. scourfieldi from all other species is the presence, on the second joint of the pos- terior maxilliped, of a series of short marginal spines.’? Length 1.4 mm. It may be added, that, in a figure of what is considered a va- riety of C. scourfieldi, the armature of the outer ramus is figured as it occurs in C. leuckarti, while that of the inner ramus is obviously inac- curate. *Cyclops oithonoides Sars. Very slender, thorax twice as long as wide, abdomen narrow, length compared to that of the thorax as 9:13. Stylets about twice as long as wide, strongly divergent, with short sets; the lateral seta near the ENTOMOSTRACA OF MINNESOTA. Sh) middle of the outer margin, outer terminal seta short, the outer median seta as long as the innermost, inner median a little longer. Antenne long, slender, reaching the middle of the fourth segment, some of itssete greatly elongate, formula, = ~-_ = -___~_ SRI peek : the last two segments have a narrow hyaline membrane which is entire. Armature of fourth feet as follows: ex. 2 spines. ex. 1 seta. Outer ramus | 1 spine, 1 seta. Inner rama | 8p 2 spines. in. 3 sete. in. 2 sete. Fifth foot with short, broad basal joint and an oval elongate apical segment bearing two sete. The receptaculum is elongate, with two curved proximal branches. Length 0.87 mm. Oyclops dybowskii Lande, which seems hardly a good variety of C. oithonoides, is said to differ from it in the following major ‘points: The antenne are shorter and more stout, minute differences occur in the chitin plates which unite the base of the third pair of feet and the lamella of the fifth foot. In fact the differences are less than may be found in any of our species when collected in different stations. Cyclops bisetosus Rehberg. PLATE XXIII, Fies. 9-11. Sars ’62.(bicuspidatus); Rehberg ’80; Forbes ’82 (insectus); Herrick ’84 (insectus); Schmeil ’92. Cephalothorax depressed, first segment of moderate size, angles of segments rounded. Abdomen long, its length to that of the thorax as 26:39. First segment enlarged, as long as the following. Stylets long, lateral seta near the end, small teeth externally and the basal one-fourth, inner and outer terminal setz small, median sete rather long, the longer as long as the abdomen, the shorter two-thirds as long. Antenne 17-jointed, little longer than the first thoracic seg- ment. Fifth foot resembling that of 0. vernalis, with a small but broad basal joint with a long lateral seta, apical segment with a long seta and short spine. The swimming feet are armed with three spines exter- nally (C0. pulchellus has but two). Length 1.3 mm. As figured by Schmeil, this species differs strongly from C. bicuspidatus and is nearer to C. parcus. Whether Cyclops insectus Forbes, is really this species must, in the absence of authentic specimens, be left open. Cyclops strenuus Fischer. PLATE XXIII, Fias. 12, 13. Fischer ’51; Lilljeborg ’53 (quadricornis); Claus ’57 and ’63 (brevicaudatus, and fur- cifer); Sars ’63 (scutifer, abyssorum, and strenuus); Lubbock ’63 (brevicaudatus, an clausii); Fric ’72 (brevicaudatus); Uljanin ’75 (vicinus, and fedtschenkoi); a SET ee ey ok PORE Morey, TE 100 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. Hoek ’78 (brevicaudatus); Brady ’78 (pulchellus, and strenuus); Herrick ’84; Daday ’85 (claudiopolitanus, hungaricus, paradyi, elongatus, and strenuus); Vos- seler ’86 (lucidulus, bodamicus, and strenuus); Sostaric ’88 (quadricornis) ; Thall- witz ’90 (lucidulus); Lande ’90 (vicinus, and strenuus); Richard ’91; Branly 91 (abyssorum, vicinus, and strenuus); Schmeil ’91 and ’92. This species is said to be one of the most abundant on the continent of Europe and assumes a great variety of forms whose relations are far from clearly understood. The cephalothorax is large, and the fourth and fifth segments pro- ject laterally. The abdomen is five-eighths as long and tapers distally. The stylets are slender, divaricate, longitudinally ridged above and about as long as the last three segments of the abdomen. The two median sete are relatively sbort, the inner apical being as long as the stylet and twice as long as the inner apical or more. Lateral seta small, not far from the end. The antenne reflexed scarcely reach the base of the third segment. The fifth foot is two-jointed, the basal seg- ment being small, nearly quadrangular and armed with a short ciliate seta. The apical segment is longer, with one long apical seta and a lateral spine. Length 1.5 to 2.5 mm. Schmeil observed a specimen 3.2 mm. long. Schmeil unfortunately places no reliance on the arma- ture of the feet, which, as Marsh also has shown, are of great import” ance and are fairly constant, and his figures and descriptions help but little in solving the perplexities of this multiform species. In this we are at present the less interested in that the species has not as yet been recognized in America. Brady gives greater detail and fails to offer valid reasons for sepa- rating C. abyssorum and C. vicinus from strenuus, though he inclines to believe C. abyssorum a deep sea variety of C. vicinus=C. pulchellus of his monograph. The formule for the feet in abyssorun are as follows: First Foor. ex. 2spines. ex. i1seta. Outer ramus { ap. 1 spine, 2 setz. Inner ramus + ap. 1 spine, 1 seta. in. 3 sete. in. 3 sete. THIRD Foor. ex. 2 spines. ex. 1 seta. Outer ramus jap. 1 spine, 1 seta. Inner ramus ; ap. 1 spine, 1 seta. in. 4 sete. in. 3 sete. FouRTH Foor. (ex. 2 spines. ex. 1 seta. Outer ramus ee: 1 spine, 1 seta. Inner ramus 4 ap. 2 spines. in. 3 sete (4 sete ?) in. 2 sete. The only difference of importance between the two species seems to be the shorter antennee of CO. vicinus. Pe eee ee see Oe ae Seen meld nt tah Dy « . : A eee ly Toe oY oi z | ee ENTOMOSTRACA OF MINNESOTA. 101 Cyclops lacustris Sars. Cephalothorax sub-ovate, truncate in front. Abdomen of equal width throughout; caudal stylets longer than the last two segments of the abdomen; terminal sets of moderate size, inner three times as long as the outer, internal pair nearly equal. Antenne as long as the first two joints of the body. The inner ramus of the fourth foot has the exterior spine very small. Second joint of fifth foot small and external spine minute. Length 1.5mm. It is suggested by Schmeil that this species, with C. scutifer and OC. abyssorum, should be regarded as synonyms for C. strenuwus. Upon this matter I can offer no opinion, nor does the brief description repeated above help the matter much. * Cyclops pulchellus Koch. Koch 41; Sars’ 57; Claus ’57 and ’63 (bicuspidatus); Heller ’70 (bicuspidatus); Fric ’72 (bicsupidatus); Hoek ’78 (bicuspidatus); Rehberg ’80', and 807, (helgolandicus) ; Vejdovsky ’82; Herrick ’83 (pectinatus) ; Forbes ’82 (thomasi); Daday ’85 (entzii, and pulchellus); Vosseler ’86; Sostaric ’88; Thallwitz ’90; Lande ’90; Schmeil ’91 and 92 (bicuspidatus); Richard ’91 (bicuspidatus); Brady ’91 (bicuspidatus, and thomasi); Forbes ’91 and ’93 (thomasi); Marsh ’93. Schmeil and Marsh agree in regarding C. thomasi of America as identical with 0. cuspidatus, and in this we are inclined to concur in spite of certain differences in variable characters. Instead of the original description of Forbes, we reproduce that given in the Report on the Invertebrate Fauna of the Yellowstone Park, It is to be noticed that Forbes regarded, in his earlier report, certain Spines as apical (in his description of the feet) which may be more logically described as lateral. A long and slender species, with 17 jointed antennz, oval cephalo- thorax, somewhat closely articulated, slender abdomen, very long and slender caudal rami, and two developed set to each ramus, the longer of which is about twice as long as the shorter. The cephalothorax is widest near the middle, its greatest width a little more than half its length. Posterior angles not prominent or produced, except those of the last segment, which are slightly pro- duced outwards. Sides of the first segment subparallel, rounding slightly toward the front, the segment itself twice as long as the other segments combined; the second segment shorter than the third, but longer than the fourth; the fifth reduced to a narrow linear band, as seen from above, the extremities of which project a little beyond the lateral outline. Abdomen with furca, a little shorter than the cephalothorax, its greatest width one-fourth of its length, including furca. First segment in the female as long as all the others together, broadest in front, its lateral outlines emarginate behind the anterior angles. Posterior margin of last segment serrate beneath and at sides; 102 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. those of other abdominal segments smooth. Furca as long as the last three segments, the width of the rami about one-seventh of their length. The inner of the two longer setz as long as the entire ab- domen, the outer of the two half that length. The outermost of the terminal sete two-thirds the length of the inner, i. e., about one- fourth the length of the caudal ramus. Rami slightly curved out- wards, with one large spine and a few small ones a little beyond the middle of the outer surface, and a vertical comb of small cps at one-fourth the distance from the proximal end. Antenne of the female moderately robust, reaching about to the middle of the third segment, without accessory structures or append- ages, the three terminal segments gradually increasing in length, the antepenult two-fifths of the last. The two segments preceding the former, taken together, shorter than the last segment and about equaling the penultimate. The armature of the swimming feet is as follows: FIRST FEET. ex. 2 spines. ex. 1 seta. Outer ramus |. 2 sete. Inner ramus {8 1 spine, 1 seta. in. 2 sete. in. 3 sete. SECOND FEET. ex. 2 spines. ex. 1 seta. Outer ramus j ap. 1 spine, 1 seta. Inner ramus jap. 1 spine, 1 seta. in. 3 sete. in. 3 sete. THIRD FEET. ex. 2spines. ex. 1 seta. Outer ramus | 1 spine, 1 seta. Inner ramus <; ap. 1 spine, 1 seta. in. 3 setz. in. 3 sete. FourRTH FEET. ex. 2 spines. ex. 1 seta. Outer ramus | 1 spine, 1 seta. Inner ramus {sp 2 spines. in. 3 sete. in. 2sete. Fifth pair of legs of two segments, the basal segment about as long as broad, with a strong plumose spine from the outer angle, the ter- minal segment cylindrical, twice as long as broad, with two terminal sete, the outer of which is as long as the seta of the preceding segment, the inner a little more than half the length. Total length, without setce, 1.33 mm., greatest depth a trifle less than one-third the length of the cephalothorax. Yellowstone lake, Great Lakes, ete. OC. pulchellus is said to be pre-eminently the pelagic species of the Great Lakes. * Cyclops pulchellus var. navus Herrick. Herrick ’82 (C. navus), and ’84 (C. pulchellus var. navus); Marsh ’93 (C. navus). This form or variety inhabits shallow pools and is larger than C. pulchellus. It also has much shorter stylets and differently propor- tioned antennie, ete. Length 1.5 mm., thorax 0.9 mm., abdomen 0.6 ENTOMOSTRACA OF MINNESOTA. 103 mm., stylets 0.14 mm., last two abdominal segments 0.16 mm., antennz 0.7 mm., first segment of body 0.5mm. The basal segment of the antenne is long and ornamented with several transverse series of spines; the last two segments are equal and longer than the preceding. The armature of the first and fourth feet is identical with C. thomasi, as is the form of the female openings and the fifth feet. The form of the first feet, caudal stylets and other details were correctly figured on Plate V of the Cyclopide of Minnesota. Specimens of Cyclops pulchellus (thomasi) were obtained from a cistern which is supplied solely by rain-water. The eggs must have been in- _ troduced in ice which had been placed in the cistern at least a year previously. The cistern is entirely dark, so that these animals must have been deprived of light for many generations. The general color was, of course, very white; the eye spots were pale, but present with some pigment and the lenses. No noticeable alteration in form had resulted. * Cyclops minnilus Forbes. Forbes °93. A small slender species with 17 jointed antennz, with narrow and loosely articulated cephalothorax and salient thoracic angles, slender abdomen, long narrow furea, and but two well-developed caudal set for each ramus. The antenne reach to the posterior margin of the second distinct segment, and are of very nearly the length of the ab- domen (excluding the caudal sete). The greatest width of the thorax is contained two and one third times in its length, and the furea is very nearly half the length of the remainder of the abdomen. The diameter of a ramus is about one seventh its length. The rudimentary inner caudal seta is a trifle longer than the outer, and about a third the length of the ramus; the longest seta as long as abdomen and furea; the next in length less than half the longest. The armature of the legs is as follows: FIRST FEET. ex. 1 seta. 1 seta. Outer ramus |%P 1 spine 2 sete. Inner ramus \m ap. 1spine, 1 seta. in. 2 sete, 3 sete. SECOND FEET. ex. 2 spines. . 1 seta. Outer ramus {sp 1 spine, 1 seta. Inner ramus {80 1 spine, 1 seta. in. 3 sete. 3 sete. THIRD FEET. ex. 1 spine. 1 seta. Outer ramus {i *2 spines, 1 seta. Inner ramus {8° 1 spine, 1 seta. in. 3 sete. 3 sete. FOURTH FEET. ex. 1 spine. 1 seta. Outer ramus {se *2 spines, 1 seta. Inner ramus {st p. *2 spines. in. 3 sete. 2 sete. ——_ * In each case one spine twice as long as the other. 104 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. Rudimentary legs of fifth pair distinctly articulated, basal article with a long seta at its outer distal angle, and second article with two sete at its blnnt tip, the outer the longer. From Duck lake. Neither figures nor measurements are given, and the form of the fifth foot is left to conjecture. In this difficult section of the genus it is very hard to place species even when all the details are clearly before us. The original description is reproduced with only verbal alteration for the sake of brevity. * Cyclops forbesi Herrick. Forbes 93 (serratus*). A very long, narrow, loosely articulated species with strikingly salient thoracic angles. Cephalothorax broadest far forward and lobed in front, between the 17-jointed antenne. Abdomen long and slender, with very long and narrow caudal rami, and but two devel- oped sete to each ramus. The first segment is but little longer than wide (eight to seven), is broadest across the middle, and excavate in front at the base of each antenna, leaving a thick, median, projecting lobe. The second segment is nearly a fourth as long as the first, and but little narrower, broadest across its posterior angles, which, though blunt, are so strongly salient that the lateral margins are decidedly sinuate. The third segment is. as long as the second, but narrower, and with its sides more nearly parallel. The fourth and fifth seg- ments are progressively shorter and narrower, the latter being trape- zoidal, as seen from above, and separated from the first abdominal segment by a deep acute emargination. The abdominal segments areas long as the cephalothoracic segments two to five taken together, and the furca is as long as the last three segments. The first segment of the abdomen is broadest in front, where its width is nearly as great as its length. The second is as broad as long, the third and fourth equal, the fifth a little shorter, the last with a row of fine spinules around the base of the rami. The width of each ramus is contained nearly eight times in its length. Besides the lateral spine, situated a little before the posterior third of the ramus, there is a cluster of two or three minute spines at its an- terior fourth. The outer and inner terminal sets are reduced to short subequal spines about twice as long as the ramus is wide. The other setee are slender, plumose, the inner nearly twice as long as the outer. The antennz are rather stout and short, 17-jointed, reaching to the end of the second segment. They are without special structures or appendages. [This probably means armed as usual, but without knife ridges or spurs.] Armature of the legs as follows: * This name is preoccupied by C. serratus Pratz. 1866. ENTOMOSTRACA OF MINNESOTA. 105 FIRST FEET. ex. 1 spine. ex. 1 seta. Outer ramus 4 ap. 1 spine, 1 seta. Inner ramus ;ap. 1 spine, 1 seta. in: > /2 Sete. in. 3 sete. SECUND FEET. seta. spine, 1 seta. ap. 1 spine, 1 seta. Inner ramus sete. in. 3 setx. Outer ramus THIRD FEET. seta. spine, 1 seta. sete. ex. 1 spine. ap. 2 spines, 1 seta. Inner ramus in. 3 sete. Outer ramus . = OS © . Sere © HL =) ro wre FOURTH FEET. ex. 1 spine. ex. 1 seta. Outer ramus jap. 2 spines, 1 seta. Inner ramus jap. 2 spines. in. 3 sete. in. 2 sete. The fifth feet are two-j vinted, the basal joint broad, quadrate, with a seta at its outer angle; the second cylindrical, with one long and one short seta at tip. Length, without sete, 1.34 mm. * Cyclops signatus Koch. PLATES XX, Fies. 8-11, 21; X XI, Fia. 16. Jurine ’20 (monoculus quadricornis albidus and m. g. fuscus); Koch ’41 (signatus, and annulicornis); Baird ’50 (quadricornis var. b and var. c); Claus ’57 and ’63 (coronatus and tenuicornis); Sars ’63 (annulicornis, tenuicornis, and signatus); Lubbock ’63 (coronatus, and tenuicornis); Fric ’72 (coronatus, and tenuicornis) + Poggenpol ’74 (clausii); Uljanin ’75; Hoek ’78 (coronatus, and signatus) Brady ’78 (tenuicornis, and signatus); Cragin ’83 (tenuicornis, and C. signatus fasciacornis) ; Herrick ’82 and ’84 (tenuicornis); Daday ’85 (tenuicornis, and signatus); Vosseler 786 (tenuicornis, and signatus); Forbes ’87 (gyrinus); Sostaric ’88 (fuscus); Thall- witz ’90; Lande ’90; Schmeil ’91 (albidus); Brady ’91; Richard ’91 (fuscus, annul- icornis, and tenuicornis); Schmeil ’92 (fuscus, and albidus); Marsh ‘92; Turner ’92 (tenuicornis). Of the identity of the two varieties which have so long been recog- nized as distinct species (C. tenwicornis and C. corunatus) the writer has little doubt. The development history has been traced sufficiently to settle this point. This combination was first made by the writer, and not by Brady, as Marsh implies. Cephalothorax large and broad, considerably longer than the abdomen. First thoracic segment large, more than half as long as the whole thorax. Abdomen rather short, cylindrical. Stylets short and not tapering, shorter than the preced- ing abdominal segment. Setz very plumose, three of them long, the longest being about as long as the abdomen, the innermost being nearly half as long and the outermost apical seta short. In the male the first thoracic is much longer and the abdomen relatively shorter. Antenne long and the terminal joints attenuated, the last three being armed by hyaline plates. Fourth foot with the following armature: =e . } J 106 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. ex. 2 spines. (ex. 1 seta. Outer ramus 4 ap. 1 spine, 1 seta, Inner ramus 4 ap. 2 spines. in. 4 spines. in. 2 sete. The spines are serrulate and the sete very plumose. Fifth foot two-jointed, basal joint longer than wide, with a series of small teeth and a long seta, apical joint with three plumose sete. Color bluish or banded, the antennz especially banded on the fifth to sixth and — twelfth to fourteenth joints. * Cyclops signatus var. coronatus. PLATE XV, Fies. 1-4. First segment of thorax long, its length to that of the entire thorax about as 1: 1.50. Last segment of antenne with the proximal portion of its hyaline plate coarsely serrate. Caudal stylets short, ciliated internally, length to width as 1.25:1. Second segment of antennules short. Inner apical seta of stylets one-third longer. Color marked. * Cyclops signatus var. tenuicornis. PLATES XV, Fias. 5-7; XX, Fries. 1-7; XX XIII, Fras. de First segment of thorax shorter, its length to that of the entire thorax as1:1.9. Last segment of antenne with unserrated lamella. Caudal stylets longer, length to width as 2.1:1, inner aspect not ciliated. Outer apical seta half as long as inner. Second segment of antennules longer. Color variable but always banded or splotched. It is also generally true that the ovisacs in the present variety are more strongly divaricate than in the variety coronatus. Schmeil also finds differences in the form of the receptaculum and sexual elements. Over against the above differences must be set the close agreement in the armature of the feet and the fact that the late stages of coronatus remain to be described while it is always associated with C. tenuicornis, generally in greater numbers. The greater hairiness and stronger serrations of ©. coronatus are characters suggestive of advanced age, as has been observed in other species. C. tenwicornis is frequently found without C. coronatus, but the reverse has not been found true in our experience. Finally attempts at experimental rearing of coronatus from tenuicornis have been made, and, while some possible sources of error unfortunately crept in, yet I am morally conyancrd that the ap- parent transformation was genuine. Dr. Schmeil discusses this question at length without adding any- thing to the evidence. He adduces the differences in structure, though he fails to find anything but such as consist in altered pro- portions of structures common to both. He claims that embryos of ENTOMOSTRACA OF MINNESOTA. 107 C. coronatus are ‘ allgemein bekannt,”’ though adding that Rehberg ad- mits that the young of the two species cannot be distinguished until the last moult, which seems to show that the late larve of C. coronatus are hardly ‘‘allgemein bekannt’’ even in Europe. Finally Schmeil denies the possibility of sexual precosity with the general statement that ‘‘Auch mir ist trotz der grossten Aufmerksamkeit unter den vielen Tausenden der von mir beobachteten Copepoden noch nicht ein einziges Mal eine solche Larve mit Hiballen zu Gesicht gekommen.”’ To this we can only say that such larve have been frequently seen during the last ten years, though only under certain conditions of time and place. Itis hoped to furnish conclusive evidence on this head svon if it is really needed. We had supposed that such precosity was now a well-recognized fact. It is to be hoped that careful embryolog- ical and biological studies may be instituted upon the Copepoda. Cyleops languidus Sars. PLATE XVII, Fias. 19, 11. Sars ’63; Herrick ’84; Schmeil ’91 and ’92; Richard ’91. This species has not yet been encountered in America, and from the extended discussion of Schmeil we still think there is considerable probability that this form is an illustration of retarded development of some 17-jointed species, perhaps ©. bicuspidatus. Cephalothorax attenuated anteriorly and posteriorly, narrow. . Abdomen slender. Stylets exceeding in length the two preceding segments. Lateral seta at two-thirds the length from the base, two median sete long, two lateral apical setz very short, the outer a ser- rate spine. Antenne slightly longer than the first segment, with short sete, 16-jointed by the more or less complete fusion of the third and fourth segments. First feet with both rami two-jointed, formula: ex. 3 spines, ex. ‘1 seta. Outer ramus jap. 2 sete. Inner ramus ; ap. 1spine, 1 seta. in. 3 sete. in. 3 sete. Second foot with a three-jointed outer and two-jointed inner ramus. Formula as follows: ex. 2 spines. ex. 1 seta. Outer ramus { ap. 1 spine, 1 seta. Inner ramus + ap. 1 spine, 1 seta. in. 3 sete. in. 4 sete. Note.— The following measurements will serve to illustrate the usual proportions of variety tenuicornis: Total length, including stylets, 1.4 mm., first segment of thorax 0.5 mm., whole thorax 0.85 mum., abdomen 0.52 mm., stylets 0.10 mm., antenne 0.85 mm., last joint of antennz 0.05 mm., longest caudal seta 0.55 mm., inner seta 0.30 mm. The corresponding measurements of C, curonatus are the following: Total length 1.66 mm,, first seg- ment 0.67 mm., entire thorax 1.12 mm., abdomen 0.54 mm., stylets 0.07 mm., longest seta 0.6 mm., inner seta 0.3 mm., antenne 0.95 mm. 108 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. As very strong evidence of our observation of the occurrence of sexual adults with larval characters may be noted a statement of Schmeil himself, who nevertheless seems to be so given to his theory as to be quite unable to see its bearing. Hesays: ‘‘ Nicht unerwahnt soll bleiben, dass zwischen den exemplaren dieser art, welche den Timpeln des Brockengipfels entstammten, sich eine Anzah] Mannchen vorfanden, bei welchen samtliche Aeste der Schwimmfiisse aus je drei Segmenten bestanden. Dieser Fall ist desshalb besonders interessant, weil hier ein Fortschreiten nach Vervollkommnung im Korperbau eines Tieres direct zu konstantiren ist.’? The writer is obliged to. confess that he cannot understand why it is not more natural to regard the two-jointed condition (which is common to all larve) as a retarded or atavistic state, from which the species tends to escape toward the norm under favorable condition, than to postulate an exceptional specific norm (which in this case is confessedly unstable), and assume that from some cause, utterly unknown to us, the form tends to ‘‘pro- ceed to a greater completeness in structure.’’ The ‘‘greater comple- tion”’ or realizing of its ideal —‘‘Vervollkommnung’’—implies that it- is incomplete or has failed to attain its specific possibilities, unless, indeed, the generic characters have for Schmeil a sort of metaphysical cogency or power over its members apart from its heredity. Thesame considerations apply to the antenne. The fifth feet are as in C. bicus- . pidatus, The form of the receptaculum is much relied on to differen- tiate this form, but is admitted to vary within wide limits. Length 0.86 to1.1 mm. Motions slow. * Cyclops modestus Herrick. PLATE XXI, Fias, 1-5. Herrick ’83 and ’84; Marsh ’92. This small species, 1.0 mm. long, was first recognized in Cullman county, Ala., but occurs also in our lakes. The color varies, but very characteristic is the peculiar shining or glaucous surface of the strongly arched thoracic shield and the evenly curved segments of the abdomen. The antenne reach but little beyond the very long first segment; they are usually 16 jointed, but I have notes of a similar form in which the antenne are 17-jointed. The feet are all three-jointed -and armed as follows: First Foor. ex. 3 spines. ex. 1 seta. Outer ramus jap. 1spine, 1 seta. Inner ramus jap. 2spines, 1 seta. in. 3 sete. in. 2 sete. SECOND Foor. ex. 3 spines. ex. 1 seta. Outer ramus |i 1 spine, 1 seta. Inner ramus {fe 2 spines. in. 4 sete. in. 1 spine, 2 sete. ENTOMOSTRACA OF MINNESOTA. 109 THIRD Foot. ex. 2 spines. ex. 1 seta. Outer ramus jap. 1 spine, 1 seta. Inner ramus + ap. 2 spines. in. 4 sete. in. 1 spine, 2 sete. FourtTH Foor. ex. 2 spines. ex. 1 seta. Outer ramus {tp 1 spine, 1 seta. Inner ramus {sp 2 spines. in. 4 sete. in. 2 sete. The fifth foot is obscurely three-jointed, the second joint bearing a short spine and the terminal joint two spines of varying length. The caudal stylets are once and a half as long as the last segment, and are peculiarly excavated for more than the caudal one third, beginning at the point where the lateral spine is situated. The outer apical seta is short, the median set are rather short while the inner seta is nearly as long as the outer median. , All these sete are pectinate. The recep- taculum seminis is elongate oval. The antenna of the male is divisi- ble into five regions, the third being formed by the thickening and union of four or more segments. Color violet or purplish red. * Cyclops capilliferus Forbes. PLATES VI, Fia. 13; XXVIII, Fias. 1-4. Forbes 793. This is a symmetrical, compact Cyclops, with the cephalothorax closely articulated, widest in the middle, and the sides regularly con- vex, with the abdomen narrow and slender, with three well developed caudal sete, and 16 jointed antenn bearing several very long sete. The abdomen, with candal furca, is contained a little less than twice in the cephalothorax, and the breadth of the latter is just half its length. First segment very long, five times the length of the sec- ond; second and third equal; the fourth very short, on the median line semicircularly excavate behind. The abdominal segments in the female diminish regularly in length from first to last. The caudal rami are twice the length of the last segment and one fourth as broad as long. The lateral set& is placed a trifle beyond the middle of the ramus; the outer terminal seta is a short, naked spine; the other three well developed and plumose. The inner and outer of these are of nearly equal length, the latter a little longer, the middle one much the longest one of the group. Antenna moderate, reaching about to the middle of the second segment of the cephalothorax. Sixteen- jointed in all adult females, and further especially distinguished by the presence of very long flexible setz upon the first, third, tenth and fourteenth segments. Terminal setz likewise very long. The seta borne by the first segment extends to the twelfth; that of the third reaches to the fourteenth; that upon the tenth segment extends to the 110 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. tip of the antenna, and that upon the fourteenth far beyond it. The first segment is as long as the two following, and very nearly twice as long as wide. The second is very short, its length one-fourth its width, and the length and width of the third are equal. Of the three terminal segments the penultimate is longest, being twice as long as broad; the antepenult two thirds the length of the following; the last is about as wide as long. The armature of the legs is as follows: FIRST FEET. ex. 2 spines. ex. 2 sete. Outer ramus ;ap. 1 spine, 2 sete. Inner ramus jap. 2 sete. in. 3 sete. in. 1 seta. SECOND FEET. ex. 2 spines. CX. wu use tee. Outer ramus jap. 1 spine, 2 sete. Inner ramus 4 ap. 2 sete. in. 4 sete. in. 1 seta. THIRD FEET. ex. 2 spines. ex. 1 seta. Outer ramus { ap. 2 sete. Inner ramus { ap. 2 sete. in. 4 sete. in. 3 sete. FourRTH FEET. ex. 2 spines. ex. 1 seta. Outer ramus fe 2 sete. Inner ramus {sp 2 sete. in. 4 sete. in. 2 sétee. The fifth feet are two-jointed, the terminal joint with one long and one short seta at tip; the basal joint with one long seta without. Length without sete 1.2mm. Grebe lake, Yellowstone Park. *Cyclops insignis Claus. PLATES XXII, Fries. 11-14; XXIII, Fias. 6, 7. Claus ’57 and ’63; Sars ’63; Fric ’72; Brady ’68 (lubbockii) and ’78 and ’91; Rehberg 80; Herrick ’84; Richard ’91; Schmeil ’91 and ’92. Schmeil has doubtfully identified C. lubbockii Brady with the brack- ish varieties of ©. bicuspidatus = C. helgolandicus Rehberg. Though the names are given in the synonomy abOve, it is with the under- standing that they at least constitute a distinct variety. The typical form has an elliptical cephalothorax, the first segment being more than half as long as the remainder. The abdomen is rela- tively short and its first segment greatly expanded. The stylets are very long, fully half as long as the rest of the abdomen, and are longi- tudinally ridged as in C. strenuus. The lateral apical setz are short, while the median ones are long and more nearly equal than usual. — Antenne 14-jointed,"not much longer than the first segment of thorax, similar to ©. strenuus. Fifth foot exactly as in C. strenuus. Length 2.5 to 5.0 mm, ENTOMOSTRACA OF MINNESOTA. 111 In the previous edition it was suggested that this is but an atavistic form of C. pulchellus = C. strenuus, and although Schmeil does not accept this suggestion, he adds strong probability to it by noticing that the eighth joint of the antenne show indications of subdivision and have the armature requisite to correspond with ©. strenuus aftersuch division. Against the suggestion he urges, (1) that this form isnotsimply found in scattered individuals but in large groups; (2) that there seems no sufficient reason for such suppression; (3) that the animal is often very large, and we should therefore expect it to attain its full development. ‘To these it must be replied (1) that it is very common for Copepods of a given stage to be associated almost to the exclusion of others, thus the net will sometimes bring in from a given locality almost solely half grown Diaptomi where on a previous visit adults preponderated; (2) that we know too little of the biology of these ani- mals to plead our ignorance as a reason for rejecting what is anatom- ically probable; (3) rapid increase in size (unusually rank nutrition) may be just a condition for retardation of development, as it often is in other groups of crustacea. Questions of this nature demand careful and continuous observation and experiment, and should not be arbi- trarily closed by a prioré arguments. Respecting C. lubbockii Brady, whether it should be considered an atavistic form of C. strenuus or of C. bicuspidatus is difficult to say. Its brackish habitat speaks strongly in favor of its not being a distinct or permanent species. The short first thoracic segment and antennze incline me to ally it to the latter species. Specimens sent me by Mr. E. A. Congdon of Columbia College, from Long Island, seemed iden- tical with C. lubbockii Brady, and if this form cannot be brought into relation to a 17-jointed species, Brady’s earlier name should be revived. It must be observed, however, that the American specimens were within direct influence of the sea. *Cyclops serrulatus Fischer. PLATES XV, Fias. 8-11; XIX, 2-5; XXVI, Fie. 10; XXIX, Fias, 17-19. Fischer 751; Lilljeborg ’53; Clats ’57 and ’63; Sars ’63; Lubbock ’63; Heller 70; Fric 72; Hoek ‘78; Brady ’78 (serrulatus var. montanus, and serrulatus); Uljanin "75; Herrick ’82, and ’84 (serrulatus var. elegans, and serrulatus); Rehberg ’80 (agilis); Cragin ’83 (pectinifer); Daday ’855 (agilis); Sostaric ’88 (agilis); Thall- witz ’90 (agilis); Lande ’90 (agilis); Richard ’91; Schmeil ’91 and ’92; Marsh 192; Turner ’92. The commonest and most abundant species of the Hastern States. Cephalothorax oval, compact. Abdomen slender and about three- fourths as long as the thorax, cylindrical, suddenly enlarged before its union with the thorax. Antenne slender, reaching nearly to the 112 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. cephalic margin of the last thoracic segment, tending to assume dur- ing life the form of a rude Z, the proximal four joints forming the base; the last three joints are slender and elongate and are each armed with a hyaline plate. Antennules small, reaching about the sixth joint of the antennz. Jaws small, with large teeth. Caudal stylets over four times as long as wide, nearly as long as the last two abdom- inal segments, serrate down the outer margin. Outer apical seta changed to a very strong and serrate spine, inner seta weak, outer median seta over two-thirds as long as the inner. Formula for the armature of the feet as follows: First FEET. ex. 3 spines. ex. 1 seta. ‘Outer ramus |S 2 sete. Inner ramus {eo 1 spine, 1 seta. in. 3 sete. in. 3 sete. SECOND AND THIRD FEET. ex. 3 spines. ex. 1 spine. ‘Outer ramus 4 ap. 1 spine, 1 seta. Inner ramus +ap. 1 spine, 1 seta. in. 4 sete. in. 3 sete. FouRTH Foot. ex. 2 spines. ex. 1 seta. Outer ramus |" 1 spine, 1 seta. Inner ramus | 2 spines. in. 4 sete. in. 2 sete. The spines of the feet are strongly serrate and the sete fully pec- tinate. The fifth foot is one-jointed, having one very strong serrated spine, an apical seta and a longer inner seta. The adjacent margins of the fifth segment are serrate. Egg sacs oval, as long as the abdo- men, divaricate. Eggs few, dark. Length inclusive of stylets 1.5 mm., thorax 0.62 mm., first segment 0.32 mm., abdomen 0.42 mm., stylets 0.11 mm., longest seta 5.0 mm., antenne 0.5 mm. Color rather opaque. A pelagic form or variety has been distinguished, but it must not be confused with var. montanus of Brady. * Cyclops serrulatus var. elegans Herrick. Distingnished from the type by the greater size, and the elongation of antenn and caudal stylets. We will first of all give the measure- ments which afford a criterion for judging of the form and proportions. Total length 1.34 mm., thorax 0.76 mm., abdomen 0.40 mm., stylets 0.18 mm., greatest width 0.42 mm., inner median caudal seta 0.60 mm., outer median seta 0.36 mm., inner seta 0.08 mm. The first seg- ment of the thorax is long proportionally (0.40 mm.). The antenne are very long, reaching beyond the base of the third segment (0.68 mm.). The egg-sacs are elongate-oval, being more slender even than in typi- eal C. serrulatus; in the animal measured they were 0.50 mm. long by 0.19 mm. wide. The caudal stylets are slightly longer than the last two segments of the abdomen. The antennules are very short, and PTE ETN NEM Nas eet rene Ny SS See eee ENTOMOSTRACA OF MINNESOTA. 1S each joint has its series of fine teeth. The free lower margins of the thorax are ornamented with series of prominences, while the last seg- ment is extended into a blunt angle bearing long teeth. The last seg- ment of the abdomen is spiny-margined and is ornamented with a double row of spines at the anus. The armature of the stylets as well as that of the feet is identical with that in typical C. serrulatus. The last two joints of the antenne measure 0.1 mm. each, while the two previous measure unitedly 0.12 mm. The color is not opaque as in the smaller form usually. Brady’s var. montanus has shorter stylets than the type, but seems nearest the small dark form found in peaty waters in America. Cyclops pectinifer Cragin has no distinctive points, it being typical C. serrulatus. Marsh also finds this variety rarely elsewhere than in pelagic locali- ties, and only in occasional association with the type. Schmeil notes » discrepancies in the original measurements of the two forms, and is led to doubt their distinctness. It can only be replied that the distinc- tions insisted on do actually exist, and are very apparent when the forms are before one, and are sufficiently obvious from the measure- ments given above. Cyclops macrurus Sars. Sars ’63; Uljanin ’74 (alajensis); Brady ’78; Rehberg ’80; Sostaric ’80; Herrick ’84; Vosseler ’89; Lande ’90; Richard ’91; Schmeil ’91 and ’92. This form is so close to ©. serrulatus as to suggest the question whether it is more than a well-marked variety. From that species it differs in the shorter antenne which are hardly longer than the first seg- ment, the slender, smooth abdomen, and the greatly elongated stylets, which lack the lateral line of teeth. The feet and the proportional length of the joints of the antenne are as in serrulatus. The species occurs in Scandinavia and Germany, but rarely. Cyclops prasinus Fischer. Jurine ’20; Fischer ’60; Vernet ’71 (longicornis); Vosseler ’86 (pentagonus); Richard ’87 (pentagonus var. vichyensis) and ’91 (pentagonus); Schmeil ’91 (pentagonus) and ’92. ‘Cephalothorax broad, attenutated behind. Abdomen slender, nearly cylindrical. Stylets one and one-half as long as last abdominal segment. Lateral seta a little distad of the middle. Outer apical seta forming a strong spine and about as long as the inner slender seta. Longest seta four times the length of the stylet, shorter median seta three-fourths as long. Antenna reaching the end of third thoracic segment, proportions and armature as in C. serrulatus. Fifth foot one-jointed, closely resembling that of C. serrulatus, but the external seta is delicate and not a strong, heavy spine. Ova few, appressed. Length 0.8 to 0.9 mm. Color green. 114 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. | * Cyclops fluviatilis Herrick. PLATES XXYVI, Fies. 1-8; XXX, Fie. 1. Herrick ’82, ’84 and ’87; Cragin ’83 (magnoctavus); Brady ’91 (magnoctavus); Turner ’92; Marsh ’93. This small species, first described in America, has been encoun- tered by Brady in Great Britain, though he chooses to make the com- parison to Calanide of the original description a reason for adopting a subsequent name. It is one of the most abundant forms in many of our lakes and their outlets. In its smaller age form it is barely visi- ble to the eye, while the Jarger and particularly the highly colored condition is conspicuous especially by reason of its rapid motions. In appearance it reminds one of Cyclopsina gracilis. The body is slender, the cephalothorax being elongate, oval, with its first segment very long. In a specimen measuring 0.57 mm. to the end of the stylets, the following proportions were noted: First seg- ment of thorax 0.22 mm., second and third segments each 0.056, fourth 0.032, total length of abdomen 0.17, stylets 0.032, longest seta 0.128, outer median 0.10 mm. The antenne are nearly as long as the whole thorax, and are remarkable for the elongation of the seventh to ninth segments. There are elongated set upon the first and fourth segments. The last joint of the antenne is slightly curved and carried at an angle to its predecessor during life, giving it the appearance of being hinged. It has also the rudiment of a knife ridge. The antennules are slender and elongate. The labrum has about twelve small teeth. The maxille have the usual form. The teet are peculiar in the exceedingly long sete. The armature of the apical segments is as follows: First Foor. ex. 3 spines. ex. 1 seta. Outer ramus jap. 2 sete. Inner ramus jap. 2 sete. in. 3 sete. in. 3 setz. SECOND AND THIRD FEET. ex. 3 spines. ex. 1 seta. Outer ramus ; ap. 1 spine, 1 seta. Inner ramus jap. 2 sete. in. 4 sete. in. 3 setx. FOURTH Foor. ex. 2 spines. ex. 1 seta. Outer ramus ; ap. 1 spine, 1 seta. Inner ramus + ap. 1 spine, 1 seta. in. 4 sete. in. 2 sete. The fifth foot is small, one-jointed, and bears three small sete. The abdomen is slender, though rather short. The stylets are three times as long as broad. The outer of the terminal sete is a short spine, Shorter than the stylet. The egg-sacs are appressed and contain four or five ova in the first state and a few more in the adult. The two ee See dots Woe aN ee ee a ae ae ENTOMOSTRACA OF MINNESOTA. 115 dimorphic states are very distinct and seem, in part at least, to be governed by habitat. The colors are frequently brilliant, varying from deep indigo to greenish brown. The coloring matter is some. what irregularly distributed but is most persistent between the bases of the feet, in the last segment of the abdomen and in the last joints of the antenne. The full-grown female measures about 0.70 mm., the males being more slender. Oviferous females often have the fourth pair of feet with two-jointed rami. American authors find the species pelagie, and Brady, though he found it in ditches immediately connected with large sheets of water. Marsh notes that there is a resemblance between this species and C. pentugonus V osseler. Cyclops capillatus Sars. ‘‘Cephalothorax sub-ovate; anteriorly uniformly rounded; seg- ments projecting somewhat laterally, the last being scarcely wider than the first abdominal segment. Abdomen attenuated posteriorly; caudal rami almost as long as the last three abdominal segments, hardly divergent; the external and internal apical sete short and nearly equal, the interior of the median sete as long as the abdomen, lateral seta about in the middle of the stylet. Antenne of the first pair robust, slightly exceeding the first segment of the body when re- flexed, with the twelve joints densely covered with long and divergent hairs. The last joint of the outer rami of swimming feet are elongated and armed externally with three spines, internally with four sete; the interior apical spine of the interior rami of the fourth pair of feet longer than the exterior. Feet of the fifth pair large, with a large and thick basal segment and a small oval second joint bearing one long seta and a short spine. Ovisacs small, narrow and divergent. Eye very small. Length nearly 2.0 mm.”’ Very close to C. viridis in many points. Found only in Scan- dinavia. Cyclops ecrassicaudis Sars. Cephalothorax elongate-ovate; segments produced laterally, espe- cially the last, which extends into a somewhat procurved process. Abdomen short and thick, first segment somewhat excavated; caudal rami equaling the last two segments of the abdomen. JHxterna] apical seta longer than the internal, both short; median setz long. Antenne of the first pair 12-jointed, scarcely longer than the first segment. Swimming feet short and thick, spines and setz short; the interior apical spine of the last joint of the inner ramus of the fourth 8 See ee ert OR erat eR Py ee ee ep 116 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. foot almost twice as long as the exterior spine. Terminal joint of the fifth foot small, armed with a spine and a seta; seta of the basal seg- ment short. Ovisacs oval, somewhat divergent. Length 0.75 mm. Found only in Scandinavia. * Cyclops varicans Sars. PLATES XIX, Fias. 12 AND 13; XXX, Fies. 2-8. Sars ’63; Uljanin ’75 (orientalis); Lande ’90; Schmeil ’91 and 92. The American form which approaches nearest to this species dif- fers from it apparently in proportions. Unhappily we have only gathered the species once and our information depends on the camera drawings taken at that time. Rather slender, especially the abdomen which is nearly as long as the cephalothorax. First abdominal seg- ment very long, as long as the rest of the abdomen. Stylets over twice aS long as wide, lateral spine one third from the apex, outer lateral spine shorter than inner seta, median sete rather long, outer two-thirds as long as inner, inner three-fourths as long as abdomen. Antenne shorter than the first thoracic segment, 12-jointed, formula —=L LT =—-—=<~=-, sete of moderate length. Feet with the fol- lowing formula: FIRST FEET. ex. 3 spines. ex. 1 seta. Outer ramus 4 ap. 2 sete. Inner ramus ; ap. 1 spine, 1 seta. in. 3 sete. in. 3 sete. FourRTH Foot. ex. 3 spines. ex. 1 seta. Outer ramus ; ap. 1 spine, 1 seta. Inner ramus ; ap. 1 spine, 1 seta. in. 4 sete. in. 4 sete. Respecting the fourth foot it is plain that the last joint is homol- ogous to two fused segments, and that the separation might take place at the next moult. Fifth foot as in ©. bicolor, but the basal segment more distinct, apical segment long, cylindrical and bearing a long seta. In the form of the stylets and antenne this species corresponds to Schmeil’s figures, but the first segment of the thorax is shorter and the abdomen is more slender. The specimen from which our outline was taken was extended by pressure, while that figured by Schmeil may he a little fore-shortened. We must leave to later study the settlement of the question, as also that of the relation between this and the next. Length 0.8 mm.; abdomen 0.35 mm., stylet 0.05 mm., longest seta 0.28 mm., antenne 0.23. ENTOMOSTRACA OF MINNESOTA. ala bf Cyclops gracilis Lilljeborg. PLATE XIX, Fies. 10, 11. Lilljeborg ’53; Schmeil ’91 (diaphanus), and ’92. Apparently this is a distinct species, characterized by the slender form, especially of the abdomen, which is to the thorax as 5:7, di- vergent cylindrical stylets, short setze and form of the fifth foot and receptaculum. The antenne are slender, reaching the caudal border of the fourth segment, and are of the form of the 12 jointed species; farmula So <~__~<=~. Fifth foot with a broad basal segment and a cylindrical terminai one, which bears a short spine and a long seta. Eggs few. Feet all two jointed. Schmeil speaks of the fifth foot as one-jointed, but the fact that the basal segment is immovably soldered to the body should not prevent us from recognizing its. existence. This species has been found only in Sweden, Poland and Germany. Cyclops diaphanus Fischer. PLATE XIX, Fias. 6-9. Fischer ’53; Claus ’63 (minutus); Heller ’63 (minutus); Daday ’85° (frivaldszkyi); Sostaric ’88; Schmeil ’92. The above synonomy is derived from Schmeil’s monograph, which can hardly be considered very authoritative since its author never saw the species and offers only comparative data to discriminate this species from the last. Abdomen broader than C. bicolor, stylets as long as the two preceding segments, lateral seta nearer the base than the end. The lateral apical setz short, equal, median set as 2: 3. Antenne 11-jointed, short, only reaching the second segment. Swim- ming feet with two-jointed rami. Fifth foot with a short spine and long seta at the end of the cylindrical apical joint. * Cyclops affinis Sars PLATE XXX, Fias. 9-11. Sars ’63; Uljanin ’75; Brady ’78; Rehberg ’80 (pygmzeus); Daday ’85° (pygmeus, and affinis); Herrick ’84; Vosseler ’86; Lande ’90; Richard ’91; Brady ’91; Schmeil ’91 and ’92. Schmeil makes the statement that ‘‘Herrick regards C. affinis as ‘var. b.’ of C. phaleratus Koch, and identifies it with his C, adolescens,”’ overlooking the plain statement that ‘‘it is impossible to sufficiently identify it [the American form] with any of the above,” and the fact that Sars’ description was appended in a separate rubric. Schmeil devotes considerable time to the relations of C. adolescens and is not unnaturally provoked by the inconsistencies in the two references, which are explained, however, by two provoking typographical errors is 118 GEOL. AND NAT, HIST. SURVEY OF MINNESOTA. which were both beyond the writer’s control. The first was the dis- placement of a line in the tabulated list of species in the Alabama crustacea, by means of which the figure of C. phaleratus was referred to C. fimbriatus and the error then repeated in the making up of the description of plates; second, in the Final Report, Plate 24, in Fig. 15 the printer has set C. adolescens one line too soon, making the figure of the receptaculum of C. parcus refer to the former species. Upon this point Schmeil remarks, ‘‘Schon hieraus ergiebt sich * * * mit welcher sorgfalt Herrick die Zeichnung angefertigt hat!’’ We beg that author to transfer his irritation to the typo, and believe that the drawing in question is substantially correct!{ As to the position of CO. adolescens, more beyond. The original description of Cyclops affinis Sars is here repeated, and it justifies the doubt which, in the absence of penenue Specimens or figures, was felt respecting its position. ‘‘Antecedenti [C. phalerato] simillimus. Corpus autem minus robustum colore cceruleo vel potius glauco sat saturato insigne. Segmentum ultimum thoracicum ad marginem posteriorem extrosum pilis vel spinulis subtilissimis pectenatim exornatum. Rami caudales quam in C. phalerato aliquanto longiores, setarum apicalium interna quam externa multo breviore, intermediarum interiore altera fere triplo longiore longitudinemque abdominis superante, in medio aculeata dein vero subtile ciliata. Antenne 1-mi paris segmento 1-mo corporis multo breviores, tenues, articulis 11 com- posite. Pedes 5-ti paris distincti, uniarticulati, setis 3, quarum interior ceteris multo major et ciliata, instructi. Sacci oviferi parvi abdomini appressi. Longit. circit. 3 mm.”’ From C. phaleratus, which it closely resembles, it differs, according to Schmeil, in its more slender form, short stylets with single oblique series of spines, peculiar shape of the fifth foot and the method of motion and also especially in the number and relative length of the antennal joints and the form of this organ in the male. The formula for the length of the antennal joints in C. affnis is Soo eS 2 while that-of (5 phalerams ise SS Se The fifth foot is one-jointed, and this joint is quadrate with fines spines apically. The stylets are twice as long as broad and are orna- mented by an oblique line of small spines. The receptaculum is smilar in form to that cf C. phaleratus. The motion is a creeping or slow swimming near the surface. Length 0.85 mm. * Cyclops bicolor Sars. PLATES XVIII, Fias. 3-3e; XXI, Fie. 12. Sars ’63; Rehberg ’80 (diaphanus); Herrick ’84 and ’87 (diaphanus); Daday 785° (diaphanus); Lande ’88 (diaphanus); Richard ’91 (diaphanus); Schmeil ’91; Marsh ’92. DESCRIPTION OF THE FEMALE: The body, not including the cau- dal sete, measures from 0.65 to 0.80 mm. The following are measure- Po aca 2 in Schmeil’s reference to figures, p. 157, C. jimbriatus is referred to as C. affinis, Fig. 3, Plate I 0 ee ae ee oe : Es oe . ENTOMOSTRACA OF MINNESOTA. 119 ments of a rather small specimen: First segment of cephalothorax 0.24, second segment 0.068, third segment 0.06, fourth segment 0.036 mm.; the remainder of the body to the stylets measures 0.24 mm., while the stylets themselves are 0.024 mm. long and bear a lateral Spine about one-third their length from the apex. The longest seta is 0.24 mm. long, the outer median seta being about 0.19 mm. The body is comparatively rather slender and tapering, with an unusually long first thoracic segment. (Measurements of a large specimen of this Species may serve to indicate the observed fluctuation in size: Length 0.81 mm., thorax 0.50, abdomen 0.31, stylets 0.06, longest seta 0.40, outer median seta 0.36 mm.) The antenne are considerably shorter than the first thoracic segment, being about 0.19 mm. long, the sev- enth and eighth joints about equal and the longest of the eleven seg- ments. The first joint is very large. The antenne in a state of rest assume a curved position. The antennules are small, the terminal segment measuring (in the animal first above referred to) 0.032 mm. The labrum has six similar teeth, which are bordered on either side by a larger one. The longest joint of the outer maxilliped measures 0.06mm. All the feet are usually two-jointed in both rami. The outer ramus of the first pair of feet has the terminal joint armed exter- nally with three stout spines, terminally with two sete, and internally with three setze. The second and third pairs of feet are alike in their Spinous armature, the outer side of the terminal segment bearing three spines, the end a very large toothed spine and a seta, and the inside four sete. The fourth foot has two spines on the outside of the terminal joint, a heavy spine and a seta terminally, and four set within, while the terminal joint of the inner ramus bears externally one spine, apically two spines, and internally three sete. The fifth foot consists of a fleshy basal segment, more or less coalescent with the last thoracic segment and bearing a curved spine externally, and a terete terminal segment 0.012 mm. long, which has an apical seta four times its own length. The abdomen is slender and its last seg- ment bears a series of spines dorsally on the caudal margin. The egg- sacs are appressed and contain eight to twenty rather large ova. The color is bronzy and opaque. Although Marsh says his ‘‘specimens agree very well with the descriptions of Sars and Schmeil, the only marked difference being in the length of the caudal sete,’’ we find several points of divergence which may make it necessary to create a new variety or species. The stylets are much shorter in the American form and the sete are longer. The external apical seta is a well-formed spine. The form of the basal segment of the fifth foot is more as in C. varicans, there being a decided protuberance to receive the second joint. The receptacu 120 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. lum is also more elongate, but this is subject to considerable varia- tion. The armature of the feet, structure of antennz and most diagnostic points agree so fully that I hesitate to separate the two forms. In the description of C. diaphanus given in the first edition some of the state- ments apply to C. varicans or an allied form. The form of the recep- taculum figured on Plate R, Fig. 12, of that report may be compared with that of Plate VII, Fig. 3°, Crustacea of Alabama, to illustrate the range of variation. * Cyclops phaleratus Koch. PLATES XVII, Fias. 1-7; XVIII, Fies. 2-24; XIX Fie. 1; XXI, Fies. 6-10. Koch ’35; Fischer ’51 (canthocarpoides); Lilljeborg ’53 (canthocarpoides); Claus ’57 and ’63 (canthocarpoides); Lubbock ’63 (canthocarpoides); Sars ’63; Fric ’72 (can- thocarpoides); Poggenpol ’74 (lascious); Uljanin ’75; Brady ’78 and ’91; Herrick 82 (adolescens), and ’84 and ’87; Cragin ’83 (perarmatus); Daday ’85°; Richard 791; Schmeil ’91 and ’92; Turner ’92; Marsh 793. Body sub-cylindrical, thorax little enlarged for the genus, abdomen large and cylindrical. The transition from thorax to abdomen is less sharply marked than usual. Cephalothorax oval, first segment longer than the remainder. Abdomen shorter than thorax, stylets short and profusely spinous. An oblique row of spines passes across the stylet some distance behind the lateral spine, which is very short, and other rows of spines or teeth may ornament the inner aspect or may be absent. The whole inner aspect is also ciliate. The outer apical seta is a ciliate or toothed spine and the inner is shorter and weaker. The outer median seta is nearly as long as the abdomen and is sparsely clothed with sharp teeth. The inner median seta is about half as long and similarly ornamented. The antenna is usually 10 jointed but fre- quently is 11-jointed, (?) and is much shorter than the first thoracic segment. The swimming feet all have three-jointed rami and are strongly armed with closely set short teeth. The armature of the ter- minal joints of the fourth foot is as follows: ex. 2 spines. ex. 1 seta. Outer ramus {2 1 spine, 1 seta. Inner ramus se 2 spines. in. 4 sete. Ins 2 Sete: Egg-sacs appressed, closely filled with many ova. I here append the original description of Cyclops adolescens Herrick (—C. perarmatus Cragin) for comparison with the description of C. affinis as transcribed below, as it contains other data: ‘‘Thorax oval, broad, acute ante- riorly; last segment large and separated by a constriction from the anterior ones. The head is beaked below; first thoracic segment large and long (0.36 mm.); last thoracic segment wide, united closely with the first abdominal segment, armed with series of teeth. Abdomen DS Bete A Ci gs eit eae eae ENTOMOSTRACA OF MINNESOTA. 121 short, especially the last segment, with is toothed behind; stylets very short. The antennze are much shorter than the first segment, 11- jointed. The maxillipeds are very small. All the feet are armed with a row of very large teeth or lanceolate spines down one side; fifth foot one-jointed, with three spines, the outer being smooth, the others spiny; egg-sacs variable, narrow, appressed; eggs large, color usually dark. The animal moves like Canthocamptus, and is able to progress out of water better than other species. The following measurements will give an idea of the proportions: Length 1.26 mm., thorax 0.76 mm., abdomen 0.44 mm., stylets 0.06 mm., longest seta 0.34 mm., an- tenne 0.28 mm., width of thorax 0.44 mm.’’ Measurements of another specimen are as follows: Length 1.1mm., thorax 0.65, first segment 0.33, abdomen 0.45, longest seta 0.6. The male is more slender (0.93 mm. long) and the longest caudal seta greatly exceeds in length the whole abdomen. The antennez are strongly modified. *Cyclops fimbriatus Fischer. PLATHS XVII, Kies, 8, 9; X XI, Fie. 11; XXV, Fies. 9-14. Herrick ’82 (crassicornis), and ’84 and ’87{; Turner ’92; Marsh ’93. [The manuscript gave not the slightest hint as to date or reference in the following, given in the order of the manuscript: ] Mueller (crassicornis); Fischer; Sars (crassicornis); Hel- ler (gredleri); Fric (pauper); Uljanin (crassicornis); Brady (crassicornis, and fimbriatus); Rehberg (poppei, and fimbriatus); Daday (fimbriatus, and margoi); Vosseler; Schmeil; Richard. A-small species (0.8 to 0.9 mm.). Thorax oval, not greatly ex- panded, angles of segments rather prominent. First thoracic seg- ment forming about half the length of the cephalothorax. Abdomen rather long and thick, terete, about as long as the thorax. Last two abdominal segments armed with a row of spines at the caudal margin. Caudal stylets twice as long as the last abdominal segment. A series of small teeth in a longitudinal series generally ornaments the stylet. Lateral spine small. The outer apical spine strong, the two median sets long, spinously armed, inner two-thirds as long as the outer. Inner apical seta weak and short, pectinate. Antenne shorter than the first segment, 8-jointed; formula: --x—-~-=~, the basal joint with a small semicircular series of fine bristles. Antennules ‘short, apical segment short with but two strong sete and several smalier ones. Feet armed with spines and bristles. Formule for fourth foot as follows: ex. 2 spines. ex. 1 seta. Outer ramus {sp 1 spine, 1 seta. Inner ramus jap. 2 spines. in. 4 sete. in. 2 sete. { By a curious mistake in this paper on p. 14, the reference to Plate VII, Fig. 2, is placed opposite C. fimbriatus and not, as it should be opposite Cc. phaleratus.~ This mistake was then TepEadeaed in the description of plates, p. 56. 122 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. _ Fifth foot small, one-jointed, with three spines, of which the inner is large and serrate. Total length 0.8 mm., thorax 0.42 mm., abdomen 0.38 mm., stylet 0.09 mm., antenna 0.18 mm. Egg-sacs appressed, with few ova. Cyclops aequoreus Fischer. PLATE XXIII, Fie. 5. Lilljeborg ’53 (magniceps); Fischer ’60; Brady ’68, ’78 and ’91. Body compressed, attenuated caudad. Antenne shorter than first segment, stout, six-jointed, fourth and sixth segments longest. Fifth feet with a small basal joint and a triangular lamina bearing on the distal margin three spines and a seta, lateral margins ciliate. Abdo- men slender, first segment very long, last very short. Stylets less than twice as long as wide. Longest seta as long as the abdomen. First foot with the formula : ex. 3 spines. ex. 1 spine. Outer ramus P 1 spine, 1 seta. Inner ramus {80 2 spines. in. 4 sete. in. 3 sete. PNT Length 0.85 mm. This species lives in salt marshes and brackish pools, and is inter- esting for its departure from the generic type in several particulars. Three species of Cyclops were found by E. Pratz in 1866 in the hydrant water of Munich and described as new. The first of these, C. cwcus, is blind and colorless and has 11-jointed antenne. The second species, C. subterraneus, is doubtfully identified by Schmeil with C. bicuspidatus. The third, Cyclops serratus, is probably a form of C. viridis Jurine. Two blind species of Cyclops have been described by G. Joseph (82): ©. hyalinus and C. anophthalmus, but the descriptions are not accessible to me. Shy SR ae ee ct rv Se Pere Ue Noe eet Pie ere A HETEROGENESIS AND PREIMAGO FERTILITY IN CYCLOPS, The present writer’s views and statements in respect to the relation of sexual and anatomical maturity and the influence of the environ- ment have given rise to a running criticism occupying many passages throughout the recent monograph of Schmeil, ’92. These criticisms are so inconsistent, and at times so contradictory of the author’s own observations and statements, that it is hopeless to attempt to answer them, especially as his notions respecting varietal and specific relations seem strangely obscure. Ifa plain statement of A the position of the present writer will remove any obscurity he feels bound to offer it. SOs hee le? eek! ee eR he OST eae PRE RA IE ENE IP ra Ge NS ORR! ip Sa ries as \ 4 - ENTOMOSTRACA OF MINNESOTA. 123. First— As a matter of frequent observation and beyond all doubt, it frequently happens that a young female Cyclops becomes oviparous. before the moult, when it acquires its full adult complement of seg-, ments in the antenne and feet. Such animals are obviously larval and exhibit this fact in their small size, pale color, small number of eggs» imperfect development of serrations, spines, etc. * Schmeil himself has observed males in this stage with spermatophores and had before him a figure in my Final Report (Plate Q, 5), reprinted from the tenth annual report, in which this matter is plainly stated, of young gravid females of OC. serrulatus—a species not likely to be mistaken— with less than twelve joints in the antenne and two-jointed rami of the swimming feet. After admitting that ‘‘kein Grund vorliegt, an der Richtigkeit der Herrick’schen Angabe zu zweifeln,”’ he says ‘‘ Herrick figures, as a matter of fact, not a young form but a completely devel- oped animal, in which, to be sure, in certain segments of the antennze the normal subdivision has not taken place.’? He adds (entirely mis- conceiving my position as to heterogeny’: ‘‘ Dass hier nicht an einem Fall von Padogonie oder gar Heterogenie zu denken ist, ist selbstvers- tandlich.”’ Had he consulted the original paper Schmeil would have seen that the failure to develop a full complement of antennal joints is. but one of the symptoms of the larval state manifested by this speci- men. Moreover, such forms are found among vast numbers of adults. and larve in the midst of the most prolific seasons and in suitable situations. We claim that the next moult would have brought to this. very animal its normal adult structure. Nor is this an isolated case. Yet Schmeil could in all consistency be forced to erect a variety for such forms. In glaring inconsequence, we find, on p. 101, Schmeil says of C. clausii Heller: ‘‘Obgleich ich der Ansicht bin, dass wir es hier wohl kaum mit einer selbstandigen Art, sondern nur mit einer Jugendform einer anderen (des ©. viridis) zu thun haben,’’ ete. Second— As a second and entirely distinct point, though confused with the former by Schmeil, it is believed that many of our species, especially such as live in pools which undergo great changes with the season by reason of evaporation, intrusion of water plants or animal forms serving as food, etc., may, after reaching full maturity and bear- ing more than one generation of eggs, undergo considerable changes, or that, under these changed conditions, what is usually the uitimate condition becomes a transitory one. ‘This change may show itself not only in increased size but in enormous enlargement of the sete. For example, I have seen C. ingens with the pectinating hairs on the sete elongated till they became long hairs. All the spines and plates and serrations are exaggerated, while the relative proportions are altered. In the case of C. viridis this is especially liable to occur, because of its stagnant stations. The color changes with the rest and the change eri. —* 124 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. may be noticed in the same pool during the progress of the seasons. In these cases, according to our nomenclature, the modified form is a | post imago, and if young born from the ordinary female enter this state and produce young in turn which never reach that state, we have a case of what was termed ‘‘heterogenesis’’ in the old general sense; i. e., two cycles of development occur in the same species. Now, as these cycles are dependent on environment, the process may be termed pedogony if the term is taken in the sense indicated. What to do with such cases is puzzling to taxonomy. Itis obvious that they are quite different from the sporadic appearance of sexually functional larvee, for here we have a stage which does not necessarily belong in the history of the species, and is, as it were, Superinduced. The objec- tion raised by Schmeil against making varieties of them—i. e., that you cannot fix an arbitrary size limit— would militate against almost all geographical varieties equally. In fact, however, the changes fol- lowing the last moult are usually evident enough to produce no trouble, In the case of Cyclops signatus we are confronted by a question of fact. This is undoubtedly the most conspicuous instance, if an instance at all, of the change referred to. If the actual rearing of C. signatus var. coronatus should prove that C. signatus var. tenuicornis does not belong in its cycle then the two forms must be separated and this particular instance of pedogony disappears. We think it possible, however, to prove the contrary. Most remarkable of the many curious statements made by Schmeil on this point is the following: ‘‘ Herrick even in his later work is not in position to demonstrate among the known species a Single sexually mature larva. He is not in the position to bring a proof of a single one of his assertions. Also none of the other investi- gators has observed this, according to Herrick, common phenomenon.”’ Having overlooked my earlier paper he is surprised at the failure to again revert to it. But, after his own admissions, how he can deny the evidence of sexually mature larve is unintelligible. FAMILY HARPACTICIDE. Numerically the largest of the families of the Copepoda, this group contains predominatingly marine and mostly minute animals, fre- quently of strange and grotesque form. A few of the marine forms, in- habiting the Gulf of Mexico, are figured in the report of the Minnesota Academy of Sciences for 1881. Of the over thirty genera of the family less than a half dozen are not exclusively marine, and of these most are brackish-water residents. The genus Bradya contains blind Copepode living in slime. The name was proposed by Dana, but was dropped in the final report. Again revived by Claus, it is now in use by the best authors. ee ee ee otc coh leet Sea Le RE ee Ge ag eet el ONS Se P) ae p 2 . wes ENTOMOSTRACA OF MINNESOTA. 125 The generai form and structure closely resembles that of the Cyclopide. The following characters are the more important ones in distinguish- ing the family from the other families of the order: Body flattened or sub-cylindrical. Abdomen usually not much smaller than the thorax, from which it is not separated by a sudden constriction; antenne rather short, 4- to 10-jointed; mandibles strongly toothed, palpate; maxillz well developed, palpate; first pair of maxil- lipeds with strong teeth at the end, second pair usually forming a claw. The first pair of feet are often turned forward or prehensile; fifth pair one- or two jointed, serving as egg supports in the female. Most species live among sub-aquatic vegetation. THE SUB-FAMILY CANTHOCAMPTIN#, To which our sole genus belongs, is further distinguished from the other sub-families of Harpacticide by the fact that the second maxilli- ped has a prehensile hook. The feet of the first pair are not clawed, but have the inner branch elongated, and the palp of the mandible is one-branched. GENUS CANTHOCAMPTUS Westwood. These little animals may be secured in considerable numbers by gathering a Supply of water from among weeds in shallow ponds and permitting the debris to settle in a spot where light only touches the jar from one side, when the Canthocampti congregate on the exposed side. Canthocamptus is an elongated animal, with the body divided rather obscurely into two portions, of which the first, or anterior portion, is largest. This part of the body has five segments, each of which has at least one pair of appendages. ‘The first, consisting of the bead proper with one of the somites of the body or thorax, as is discovered by observing that a pair of legs is attached to it, is the largest seg- ment of the body. As seen from above, it is triangular and extends in front into a short, stout beak or snout, like the rostrum of a crayfish. Above the beak, in the centre of the forehead, is the eye, consisting of pigment and two lenses, showing that we really have to do with two eyes con- fluent on the median line. This is the simplest form of a compound eye. The same method of compounding the eyes is exhibited in a more complicated manner by Daphnia and other Cladocera. On either side of the beak springs an antenna with six to nine joints of unequal size. The first ‘three joints are profusely covered with hairs. The fourth joint is more slender than the preceding, and terminates ina process below, which bears besides a Jong hair a peculiar blunt os, eS RE Re eh Ate eae a ee Ok Ge ever ae Bae > : : > ae ~~ 6 * 126 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. bristle that serves some unknown purpose—probably being sensory in function like the similar hairs on the antenne of some Cladocere. The next joint is shorter than the rest, while the remaining three are spined at definite points. The antennz of the male are curiously altered, or geniculate, on both sides, as in Cyclops. The three basal joints are shortened, while more or fewer of the following ones are coalescent, followed by a hinge joint and two elongated segments. The second antennz or antennules are two-jointed, and the basal joint has a two-jointed branch or palp; the terminal joint is covered with spines; at the end are longer and curved spines, jointed in the middle. The mandible is a flattened plate with digitate teeth at the end, on one side of which springs a two jointed palp, and from the other a blunt process. The maxilla is somewhat like it, but has rudiments. of other elements. . The first pair of feet have two three-jointed rami. The outer ramus is shorter and with the longer branch is directed forward, The fourth foot has the inner branch two-jointed. The inner branch of the third foot of the male is peculiarly modified to form a pre- hensile organ, as it is this foot which fastens the spermatophore to the female. The fifth feet are composed of two flat plates. The second division of the body, the abdomen, consists of five seg- ments, of which, however, the first two are united in the female. The last segment of the abdomen bears. two stylets, which are sometimes. considered as together constituting an additional segment. Each of these stylets has, with several small spines, two elongated caudal setze, one of which is usually as long or longer than the entire abdo- men. The stylets are usually considerably longer than wide, but the proportions vary somewhat in different species. Viscera: The body cavity is traversed by the alimentary canal, which is a straight tube with no lateral cca or blind sacs, as in some other Copepoda. The canal is divided into four more or less distinct portions; the first section is a slender, muscular tube, extending from the mandibles nearly through the first segment, opening into the stomach proper, which is a muscular and glandular sae or tube, filling the greater part of the thorax; at the beginning of the abdomen, the sac is constricted and becomes the intestine proper; near the extrem- ity again there is another change and the intestine loses its glandular character, and, by a peculiar adaptation becomes a sort of force-pump, which, during life, is constantly pumping water in and out, serving as a means of respiration. This anal respiration is quite common among aquatic animals in this as well as other orders. This latter section of the canal is the rectum, and opens beneath a toothed anal _ ENTOMOSTRACA OF MINNESOTA. 127 plate, above and between the stylets. No special divarications or ceca are appended to the digestive tract, and the only other organ which is at all considered to belong to the alimentary system, is what is known as the ‘‘shell-gland,’’ present in most crustacz, but till recently thought to be absent in Canthocamptus. It is a coiled tube found in the lower part of the first segment of the thorax. It is impossble to find this organ in Canthocamptus, in every case, it being very obscure; and its office is uncertain, though it is supposed, perhaps with little reason, to be hepatic in function. There is no functional heart in this animal, but its place is taken by a peculiar apparatus, hitherto undescribed; this consists of a tube, surrounding the posterior portion of the alimentary canal. This sac around a sac is open in front, and serves by a double mechanism the office of a pulsating heart, though in a very imperfect manner. There are no true hematic or lymph corpuscles in this animal; so far, at least, none have been discovered. The place of these blood corpuscles is taken by globules of yellowish or red color of the most diverse size. These nutritive globules, or fat globules, as they have been called, are undoubtedly reservoirs of nutriment in a shape convenient for the animal’s use, and equally certainly are derived from the contents of the intestine. In those Copepoda which have a functional heart, it is open anteriorly into a general body- cavity in the same way as in this animal. That a portion of the vas- cular system should surround the alimentary canal is no unexampled thing, for in Daphnia a large sinus embraces a portion of the canal. The same provision as this described in Canthocamptus occurs in the Oyclopide. The nutritive globules are often very large, and are fre- quently extremely abundant, especially in females soon to become gravid. Three-hundredths mm. is not a large measurement for the diameter of such drops. The nervous system is very hard to trace, consisting of a large pear shaped ganglion just below the eye, from which extend commis- sures around the cesophagus, connecting them with the ventral ganglia lying between the bases of the feet. The senses are not apparently well developed, for, excepting the eyes, we cannot locate with certainty the organs of any sense. There are, however, two spots which are evidently devoted to special sense: first, the processes on the fourth joint of the antenne, which may be simply the seats of tactile sense, or may have nerves suitable for perceiving chemical stimuli; second, the area on the forehead bordered by a raised line and covered with little pits, each with a small bristle. The character of this organ can be but conjectured; it may be homologized with the frontal nervous organs of the Cladocera. 128 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. The sexual organs are quite extensively developed, and periodically obscure the remaining viscera. In the male the simple testis is situ- ated in the second segment, and the single vas deferens, after numer- ous windings through nearly the entire length of the body, opens at the base of the first abdominal segment under a spined plate. 1 ra wa (?) -------~[-~---- M Ol NA----Ceriodaphnia x ‘Daphnia : es ¢LYNCODAPHNIDA > / v2 | oS Simogephalus s < 7 ‘ ‘ x ‘Scapholeheris 4 f Macrothris- pee Streblocercus /Macrotir ie aS . _— Lyncodaphnia nf 4 ai y i N a 4 p Lathonura —-Drepanothrix Be ers /Hiocryptus | “ 1 > ! aN Acantholeberis 4 LY ne EIDA » f i | Leydigia Eurycercus oi Camptocercus_______7 ao re 7 - alee Z 2 Alonopsis-~ GSE oer at ‘\ {Alona) a — Lynceus Graptolebris { Pledroxus}, ¢ \ Chydoris nS ‘\ ‘Monospilus part of the body, or at least forms a sac for the protection of the eggs. This so called shell springs as a fold from the maxillary segment, and is the most conspicuous and variously formed, while really least im- portant, of the structural peculiarities. All Cladocera begin life with a single median eye, but some lose it during later life. In one case it remains the only visual organ. The outer covering is in most cases changed by frequent moults. The period of the moult is one of the most precarious in the life his- tory of the animal. Although figures and brief descriptions of animals belonging to this group are to be found in the works of Swammerdam, Leuwen- hoek, Trembley and others of the older authors, Mueller* was the first to produce a systematic work upon these in common with other minute fresh-water crustacea. He may be called the father of the study of micro-crustacea. Jurine,f an eminent Swiss naturalist, was the next to contribute important discoveries relating to these inter- esting animals, though Ramdohr had given anatomical details of sev- * Entomostraca, seu Insecta testacea, que in aquis Daniz et Norvegi reperit descripsit, ete. Otto Friedrich Miiller, 1785. + Monoc. qui se trouvent aux Envir. de Geneve. ‘ 144 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. eral species. Gruithuisen, a little later, gives further details of Daphnia sima (Simocephalus). The work of Milne Edwards gives a resume of what was known regarding these animals in that period. Soon afterwards the work of Baird became the beginning of a new era, and the study of the minute crustacea sprang into importance at once. The Scandivanian peninsula being the birthplace of the science, it is proper that the most exhaustive work on the group should be performed there. . The most important of the later writers are Leydig, Schoedler, Fischer, Lilljeborg, P. E. Mueller, Sars, Weismann, Claus and Kurz. The complete bibliography of the subject up to Mueller’s time is found in Baird’s British Entomostraca; the greater part of the later bibliography is to be found in P. E. Mueller’s Danmark’s Cladocera. A few only of the more important works are here mentioned, the com- plete list elsewhere given making repetition unnecessary. Lilljeborg, W., De Crustaceis ex ordinibus tribus, (or) Om de inom Skane forekom- mande Crustaceer af ordningarna Cladocere, Ostracoda och Copepoda. This valuable work is particularly good on the Cladocera, but is unfor- tunately without Latin descriptions; so that the Swedish text is a hindrance to its usefulness. It is chiefly of historic value now. Large 8vo. Lund, 1855. Leydig, Fr., Naturgeschichte der Daphniden. The most magnificent work published on this group. Surs, @. O., Om Crustacea Cladocera, iagttagne i Omegnen af Christiania, 1862. This valuable work is difficult of access, printed on thin paper and without illustrations. A second paper by the same author in 1863 is mentioned, but I have never seen it. Schoedler, J. E., Neue Beitrage zur Naturgeschicte der Cladoceren, 1863. One of the most important works on the Lynceide. Sars, G. O., Norges Ferskvands ae + Aes oh EP NS ets A ee Sheen ae Shee! eo Cn VE ee Pe eee UR boar > Cpa) ee 5

7°33 ge oe ee Ete [ Not noticed in the key: asperata, 173; minuta, 173; textilis, 173; rotundata, 173; echinata, 173. ] * Ceriodaphnia megops Sars. PLATE XLI, Fia. 20. Birge ’78 (cristata). This species is one of the largest and most readily distinguished as well as rarest of the genus. Very characteristic is the fine anasto- mosing striation which breaks up into reticulation only near the shell margins. This species seems to form the transition toward Simoceph- alus with Scapholeberis, which, however, diverges along its own pecu- . -eN ENTOMOSTRACA OF MINNESOTA. 169 liar track. The length is sometimes 1.0 mm. The head is obscurely angulated in front of the antennules, which are large. The antennules of the male are long and have hooked seta at the end. The description of Ceriodaphnia cristata given by Birge would apply in almost every particular to C. megops, though he seemed to overlook the close conformity. The size is much less (0.7 mm.), and the post- abdomen seems more abruptly truncate; moreover the number of anal spines is less. The crest upon the dorsal margin may be the effect of prominences such as are described by P. E. Mueller; at any rate, in view of the fact that but few specimens were discovered, the sugges- tion lies near that C. cristata is the young or, at least, a reduced form of 0. megops. Professor Birge writes that he now unites cristata with C. megops. Found at Southampton, Mass. Ceriodaphnia pulchella Sars. PLATE XLI, Fiaes. 14, 19. Very much like C. reticulata, but smaller. Head large, turgid, and angled in front of the antennules, forming almost aright angle; for- nices moderate; antennules rather large; shell oval, reticulated with double contour lines; post-abdomen of medium size, narrowed toward the end, slightly truncate. with about nine spines; terminal claws short, smooth. The flagellum of the male antennz is but slightly hooked, 0.5 to 0.6 mm. long. This species is not certainly identified from America, though a form with smooth claws and small fornices occurs with C. dentata in some places. Ceriodaphnia rotunda Straus. PLATES XLI, Fiaes, 12, 23; XLII, Fie. 1. Daphnia rotunda—Straus, Baird. As said by Kurz, this species is not easily mistaken; the small head (only paralleled by the following), the very evident reticulations and the broad abdomen give it a peculiar habitus which is unmistakable. Head depressed, small, spiny below, not angulated; fornices promi- nent, thorned; body rotund, almost spined above; shell doubly retic- ulate; post-abdomen broad, with seven or eight anal spines; claws large, smooth. The male antennules are little larger than those of the female. I have not yet seen this species in America. — Ta SL ae a es EL hil eee ae o , t 170 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. “¢ * Ceriodaphbnia alabamensis Herrick. PLATE XLII, Fie. 2. (American Naturalist, May, 1883. Pilate V, Figs. 11, 12.) This species was seen but once and is insufficiently known. The body is elongate, quadrate, the shell reticulated with double contour lines, the head very small and produced downward below the eye, which is very small, the antennules are longer than in any other spe- cies, obviously two-jointed, with a lateral seta; the antenne are very long; post-abdomen long and rather narrow, with the margins nearly parallel, truncate at the end, with over nine anal spines; claws smooth, abruptly truncate. My drawing represents a daphnia-like set of processes for closing the brood cavity. Length 1.0 mm. Tuscaloosa, Ala. * Ceriodaphnia reticulata Jurine. PLATES XLI, Fiaes. 15, 21; XLII, Fie. 3; XLII, Fie. 3; XLIV, Fias. 3, 4. Monoculus reticulatus—J urine. Daphnia reticulata—Baird, Leydig. Ceriodaphnia quadrangula—Schoedler. Ceriodaphnia fischeri—Ley dig, Schoedler, etc. Head long, obscurely angled in front of the antennules; fornices very prominent; antennules small; post-abdomen of moderate size, rounded at the end, slightly tapering; about eight long anal teeth; terminal claws with a series of sharp spines at the base. The reticu- lations are sharp but simple. The flagellum of the male antennule is either straight or moderately curved. Kurz says that some varieties have the fornices blunt while others are sharp. I have seen only the blunt form, which is then much like the next. [* Ceriodaphnia dentata Birge. | This form differs from the above only in having the inside of the claws fringed with minute bristles (sometimes absent), the angle of the head being more marked and the fornices less prominent. It is difficult to say whether our Minnesota specimens most resemble this or the typical C. reticulata of Europe. They seem intermediate, some having fornices with an abrupt angle. It may be instructive to quote Kurz on the European C. reticulata: ‘‘ Examples occur 0.8 to 0.9 mm. long, others on the contrary only 0.5 to 0.6 mm. long and combining with the smaller size some differential characters. In the larger va- riety I found the fornix obtuse, while in the smaller it extends ina Sharp thorn directed upward and outward. In this small sub-species ENTOMOSTRACA OF MINNESOTA. 171 the secondary teeth of the claws of the post-abdomen seemed to be absent, though in ©. reticulata three to five are constantly present.’’ Professor Birge now identifies this species with C. reticulata. Ceriodaphnia punctata P. E. Mueller. PLATE XLI, Fie. 13. Head depressed, rounded at the end, not angulated, ornamented with minute spines within the hexagonal areas. Fornices slightly prominent, either smooth or spiny; antennules very long; shell rotund, reticulated; post-abdomen of medium size, width nearly uniform, truncate below at an obtuse angle; anal spines large, increasing toward the end; claws smooth. Length 0.7 to 0.9 mm. Found as yet only in Scandinavia. * Ceriodaphnia laticaudata P. E. Mueller. PLATE XLI, FIG. 22. Ceriodaphnia quadrangula—Sars (fide Mueller). Ceriodaphnia consors—Birge. Head small, depressed, rounded at the end, not angulated; fornices prominent; shell roundish, or sub-quadrangular, moderately reticu- lated, antennules rather large; post-abdomen broad, narrowed from the middle to the end; the nine or ten small anal spines nearly equal; claws large and smooth. In P. E. Mueller’s time males unknown. Length 1.0 mm. Specimens 0.6 mm. long from Minnesota agree in most respects, but the reticulation is very marked and irregular and the terminal claws are pectinate. This form constitutes a transition to the next. | A species related to C. laticaudata, but only half the size, was found in Clarke’s lake, a small but very deep pool, containing a fauna like that of the Great Lakes. The appearance is like the small form alluded to under that species, but the claws are smooth, the head is slender and strongly angled behind the eyes, and the antennules are of rather large size. The fornices are not very prominent. The shell is large-reticulate and the abdomen is large and obliquely truncate, the anal teeth being very large and strongly curved. The only indi- viduals seen were ephippial females measuring 0.55mm. This may be * Ceriodaphnia consors Birge. PLATES XLII, Fia. 4; XLIV, Fias. 5, 6. This differs from C. laticaudata in one or two points, being about one-half the size and having fewer caudal teeth. Birge says the abdo- OIE Re LEN SRST Pat Rene ee 172 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. men is broad and obliquely truncate. The difference between being obliquely truncate and narrowed at the end in some circumstances disappears, so that really this species seems quite close to laticaudata. Found in Madison, Wis. Ceriodaphnia quadrangula Mueller. PLATE XLI, Fias. 16-18. Daphnia quadrangula—O. F. Mueller. Daphnia reticulata—Baird. Head depressed, rounded at the end, only slightly angled; fornices prominent, antennules large; post-abdomen narrow, of equal width for the lower half, rounded at the end, with about eight small spines; claws smooth, length about 0.6 mm. This species resembles a smooth- clawed D. reticulata. * Ceriodaphnia scitula Herrick. PLATES XLII, Fias. 5-8; XLIV, Fies. 1, 2; XLV, Fia. 1. One of the most abundant species of Ceriodaphnia in Minnesota is a large form much resembling (C. quadrangula. The post-abdomen is exactly as in C. reticulataor OC. dentata, which latter it resembles in having a sharp angulation in front of the antennules. The shell is oblong and heavily marked with minute, regular hexagonal lining; the upper angle is rather sharp. The head is closely appressed, the fornices are prominent and abruptly truncate at the tip, the eye is small, the pigment fleck also small; antennules short. The post- abdomen is of moderate size, narrowed toward the end and armed with about ten powerful curved spines; the terminal claw itself is large and curved, armed only with fine spines extending down the en- tire inner side. The size is 0.8 to 1.0 mm.; color pinkish, opaque; antennx, especially, often bright pink. Male 0.6 mm.; flagellum of the male antennz long; sensory filaments lateral, also one anterior, lateral flagellum. Distinguished from C. quadrangula by the prominent fornices, large anal spines, small reticulations, form of head and larger size. A small variety resembling the above very closely is the common- est form in our larger lakes; the reticulation is commonly larger but less distinct, the head is depressed and narrowed, with a sinuous upper outline. The fornices are prominent and the form of the post- abdomen is exactly as in the last. The spines of the post-abdomen are very long and seated on small eminences. The length hardly ex- ceeds 0.55 mm. The claw is densely ciliated, but not spined; these SPATE eerie ME ee eae / ENTOMOSTRACA OF MINNESOTA. : 173 smaller forms have but few eggs (two). The young have a thorn on the angle of the fornices. Plate XLV, fig. 1, represents the ephippial female of this species. There seems no reason to doubt that this is only a variety of O. scitula. The small form of C. reticulata mentioned by Kurz might be referred here, while the larger form with less promi- nent fornices is not so different from the American C. dentata. Ceriodaphnia nitida Schoedler. Ceriodaphnia quadrangula—Ley dig. This species seems to be characterized by the quadrangular form of the meshes of the shell-markings and the presence of teeth upon the claws. Probably invalid. . Oeriodaphnia asperata and CO. minuta of Moniez have remained un- known to me. Cf. Note sur des Ostracodes, Cladoceres, et Hy- drachnides observes en Normandie. Bul. d’etudes scientifiques de Paris, 1887. Ceriodaphnia textilis Dana is not sufficiently fully figured to allow of a suggestion as to its affinities. Daphnia rotundata Say is very probably a member of this genus, though the description is hardly intelligible. ‘‘ Body rounded behind; upper antennze three-branched, a small spine above at the joints; lower five-banched; color white. Length 0.5mm.’’ It is probable that we should read ‘‘upper branch of antenne with three sete,’’ ete., in which case we may identify the above with Chydorus or the like. Ceriodaphnia setosa Matile. Matile ’90. Body spherical, resembling C. rotunda and C. laticaudata, brownish red. Head small, depressed. Front uniformly rounded. A deep depression between head and body. Fornix moderate, spiny. Head and body ornamented with polygonal meshes from every angle of which springs a spine perpendicular to the surface. Antenne very short. Antennules rather long, lateral seta nearer the base than the tip. Post-abdomen large, gradually narrowed toward the end. Anal teeth seven or eight and nearly equal. Claw armed with a series of fine cilia. Eye large. Macula small. Length 0.42 to 0.57 mm.; heighth 0.27 to 0.86 mm. It is probable that this is identical with Ceriodaphnia echinata Moniez (’87, p. 512), but there are minor differences and the problem must be left open. Whee CP Pee tA a dn? oe SA SEEN. Oy Ae, ee we hee Koad! i COLE wae eo 174 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. Ceriodaphnia cornuta Sars. . Sars ’85. This interesting species furnishes further evidence of the close re- lation between Ceriodaphnia and Scapholeberis by the possession of a frontal spine or “‘horn.’? Head much depressed, with frontal part slightly dilated. A process arises directly cephalad of the eye, an- other forming a beak. Carapace broadly oval, tumid, with a bifid caudal projection from the upper angle. Whole shell distinctly retic- ulate with polygonal markings. Antennules short, fusiform, lateral seta near the middle. Two distinct abdominal processes. Anal spines about eight. Claw without basal teeth. Length 0.6mm. The form resembles C. quadrangula. The fornices are acute. . GENUS SCAPHOLEBERIS. The genus Scapholeberis stands rather closely related to Ceriodaph- nia, from which it is at once distinguished by the angled or spined lower posterior angle of the shell. The head is rather clumsy, and the continuation of the fornices runs toward the apex of the incurved beak, which commonly lies within the valves of the shell. The lower ante- rior angle has a prominence and there is a basin-shaped area inclosing the base of the antenne, part of which lies on the shell and part on the head. This area is more strongly lined or reticulated than the rest of the shell. The lower margin is straight and terminates, in most forms, in a long scythe-shaped spine which is directed backward. The shell itself is usually indistinctly reticulate or unmarked, and commonly is deep colored. The post-abdomen is very like Ceriodaph- nia or more as in Simocephalus; the anal spines are few and the older Specimens have more than the young; the place at which additional spines are to appear is marked by prominences. The eye is of mod- erate size, the pigment fleck rather small and the antennules short and hidden by the beak. The antennz are of small size and generally dark colored. The ephippium contains but one egg; the males do not have altered antenne or feet. The sexual periods fall in early sum- mer and in autumn, according to Weismann; the males appear but sparingly. The species S. mucronata is very abundant everywhere, while the others are less frequently seen. * Scapholeberis mucronata Mueller. PLATES XLIII, Fias. 4-7; XLV, Fie. 5. Daphnia mucronata—Mueller, Lievin, Lilljeborg, Fischer, Leydig, Baird, Herrick. This well-known species with rather short spines below is found ENTOMOSTRACA OF MINNESOTA. 175 abundantly everywhere. In this country at least it is characterized by a dark color. The head is large, rounded in front of the large eye, serrate below and extending posteriorly into a roundish beak, back of which are the short antennules. The fornices are very short and rounded; a line connects the fornices with the beak by a sudden de- flection downward; it sets off the area which forms a part of the basin of the antenne. A second line springing from just above the termin- ation of the fornices passes over the eye by a broad curve. The post- abdomen is truncate and bears beside the terminal claws four or more spines which rapidly decrease in size. The claws are minutely spined; the spines on the shell are of variable length, but do not exceed one- fourth the length of the remainder of the lower margin. This species ranges over all Europe and eastern United States. Length 0.6 to 0.8 mm. Scapholeberis cornuta Schoedler. PLATE XLV, Fie. 6. Monoculus bispinosus—De Geer. Daphnia mucronata var. acute rostrata—Baird. Scapholeberis mucronata var. fronte cornuta—P. E. Mueller. This Species differs from the above only in having a sharp curved horn on the head in front of the eye. The use of this appendage can only be conjectured; but it may be that, like the curved beak of Rip- ophilus, it serves to clear away rubbish in the filth in which these ani- mals frequently live, This form, be it variety or species, is not known in America. * Scapholeberis armata Herrick. PLATE XLII, Fias. 10, 11. Scapholeberis mucronata var. armata—Herrick. A very beautiful and unique species, which possesses the extreme development of the peculiarities of the genus, The head is shaped very much as in the previous species, the fornix is squarish, the basin for the antenne is small. The upper lines from the fornix meet be- hind the eye; the form of the shell is as in the above, but the spines upon the lower margin are longer. The scythe-likespine on the lower angles of the valves is extremely long, falling little short, in extreme cases, of being as long as the entire lower margin, in others about one. half as large. There are the usual lines parallel to the lower edge of the shell. The specimens having the longest spines were found in fresh water about Mobile, Ala., but the species occurs in Minnesota and intermediate points, though sparingly. Probably the earlier plan of regarding this as a variety of S. mucronata is nearer correct. eee wae ae Skee SS PP gh eee * ty 5) ig age ee Sas , \ 176 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. *Scapholeberis aurita Fischer. Daphnia aurita—Fischer. Scapholeberis nasuta— Birge. Form much as in the last, head shorter, ‘‘ prolonged into a rather sharp beak, at whose apex the continuations of the fornices unite. The beak does not project downward as in S. mucronata, but back ward, and in its natural position lies between the valves.’’ The usual reticu- lated and lined areas are present and the balance of the shell is covered with ‘‘small pointed projections.’”’ ‘‘The antennules are much larger than in S. mucronata, though they do not project beyond the rostrum.”? The pigment fleck is long and large; the post-abdomen is much as in the preceding species; the terminal claws have several fine teeth. The males have the opening of the vas deferens close behind the terminal claws; mucro short and blunt, length 1.0 mm. This species is very near the next, but differs in several particulars. It forms the transition to the next, which is the extreme of the genus in a direction converse to that pursued by the S. armata. * Scapholeberis angulata Herrick. PLATES XLII, Fias. 9, 9a; XLV, Fias. 7, 7a. Herrick ’83. Form as in the above, but comparatively larger; valves quadran- gular, anterior margin strongly arched; head short, only slightly con- cave below the eyes; the beak is as in S. nasuta, but seems to be directed more nearly directly downward than in that species. The antennules are long and resemble those of Simocephalus. The pigment fleck is square and rather large; the antenne are of the usual size. The re- ticulated areas are as in the other spesies. The post-abdomen is more as in Daphnia, not so squarely truncate and with five to seven large teeth; the first foot has one elongated jointed seta; the posterior angle of the shell has no spine, at most there is a somewhat prominent acute _angle, the inner shell layer is armed at this point with some elongated teeth as in the corresponding situation in Simocephalus. On the whole, there is a similarity to that genus in this as well as in the previous species. S. nasuta has a short spine and elongated pigment fleck, the present species has a squarish but rather large fleck and no spine; the post-abdomen has a greater number of spines than any other species. South of Tennessee river, in Alabama and Mississippi. The species of this genus are predominatingly American, four out five being found in the United States; the fifth, moreover, is more often regarded a variety of one of the others; in fact, the absence of “(ea ENTOMOSTRACA OF MINNESOTA. TG S. cornuta from America is one of the most important supports of the specific independence of the two forms. All the species delight in disporting themselves near the surface in sunny weather. GENUS SIMOCEPHALUS. Although a very well circumscribed group, this genus passes into the next rather directly by means of S. macrothroides. The connection on the other hand seems to be by the way of Scapholeberis, though there is a rather broad separation between even Scapholeberis angulata and any known Simocephalus. The enlarged spines near the angle of the shell and the form of the antennules as well as some other points, show a transition through that species toward the present genus. The general form is quadrate with the lower posterior margin sinuate; in young specimens the shell is nearly a perfect rect- angle. The upper margin is produced more or less at the point of © union with the free posterior margin, and the shell is either arched or very abruptly angled above the prominence in old females. The head is produced into a projection at the eye, while the beak proper is between the anterior margins of the valves; the pigment fleck is rather large and variously shaped. The fornices are larger than in Scapholeberis and extend to the front of the head over the eyes; the an- tennules have a lateral flagellum which is large and lance-shaped. The post-abdomen varies very little in shape; it is truncate and exca- vated below and very broad. The anal teeth are few, large, curved, pectinate; the claws are straightish and pectinate or spined; the labrum is shaped as in Daphnia; the anterior part of the stomach has the usual ceca. The members of this genus are among the most abundant and con- Spicuous of the family and are more persistent during the changing Seasons than any other form. S. vetulus, the commonest species, stands in the centre of the genus, while two extremes are expressed by the other members of the group. The winter or sexually produced eggs are lodged in an ephippium or saddle-like modification of the shell, which is finely reticulate; while the shell is usually marked by fine anastamosing lines which, in some species, show clearly their derivation from a rather fine hexagonal marking. The sexual periods, when males are produced, occur in autumn and spring. The males have few distinguishing characteristics, the form being that of the young female. Theopening of the vasa deferentia is back of the anus, hence these ducts cross the course of the intestine. They have ejaculatory muscles 178 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. about the lower part. The smaller species are frequently deeply col- ored with pink, purple and brown fatty deposits and the markings are more conspicuous than in the American EHwrycercus, which is itself often brightly spotted with blue or purple. The aspect in the water is between that of Hurycercus and Daphnia. The first mention made of any member of this genus in America is Say’s description, repeated in Dekay’s Crustacea of New York, of Daphnia angulata. This description which follows is quite sufficient to identify the genus, and indeed to indicate that either S. americanus or a related form is intended, butit is hardly competent to alter names the significance of which is quite clear. ‘*Sides striate with numerous parallel minute oblique lines; hind edge of the body with a prominent angle in the middle. Antenne with four filaments on the upper and five on the lower branch. Color white or red. Length 0.1mm. Stagnant water in the forests of the Southern states.”’ *Simocephalus vetulus Mueller. PLATES XLIV, Fia. 7; LII, Fias. 6-9. ‘Daphnia vetula—Baird, Herrick. Daphnia sima—Mueller, Latreille, Bosc, Ramdohr,Gruithuisen, Desmarest, Lamarck, M. Edwards, Koch, Gmelin, Manuel, Jurine, Lilljeborg, Leydig. This commonest and one of the largest species is apparently dis- tributed over the northern hemisphere and abounds in all the more shallow lakes. The head is rounded in front and is not angled between > the prominence of the eye and the beak. The body is very large and not abruptly angled above, the spine of the shell being inconspicuous and high, so that the free posterior edges of the shell lack little of equaling the greatest height of the shell. The shell is covered with minute dense striations which spring from the free edges. The pig- ment fleck is elongated in old specimens and the upper angle follows up beside the suture separating the antennary basin from the rest of the shell of the head. The antennules are ornamented with minute spines. At the lower angle of the shell are three curved spines which differ from the preceding filaments. The number of eggs which are produced at once is truly immense. Under favorable circumstances this species reaches a large size, falling little if any short of 3.0 mm. S. vetulus lives, by preference, among the leaves of aquatic vegetation. With us this species seems to live in the smaller pools as well as in lakes of some size. JI am not able to see any difference in this respect between the various species. PAI eS, 2 eae, peer LS ea el eee Ek eae we! é r - ENTOMOSTRACA OF MINNESOTA. 179 *Simocephalus serrulatus Koch. Daphnia serrulata—Koch, Lievin, Fischer, Lilljeborg. Head narrow, extending anteriorly into a sharp spiny angle in front of the eye. Dorsal line of the shell abruptly angled or curved pos- teriorly, projecting to form a broad obtuse spine behind; this spine is serrate with sharp teeth and lies somewhat above the middle of the height of the animal, so that the free posterior margins of the shell fall much short of reaching the greatest height of the shell. Post- abmomen of the usual form, with the claws armed with two series of spines or bristles, the outer being much the larger; anal teeth curved or angled, dentate; pigment fleck triangular or rhomboidal. Length 2.0 to 2.5 mm. I am not sure that the three following species are more than varie- ties; the first in particular is very close to the Kuropean type. [* Simocephalus americanus Birge. ] PLATE XLV, Fia. 9. My own observations of this form made throughout the Mississippi Valley are not in complete accord with the description of Birge, but it seems improbable that there is any mistake in the identification. The very generally distributed form on which this species rests is subject to marked variations within certain limits. This species dif- fers from S. serrulatus in the following points. The head, although prominent and spiny near the eye, is not angled between this promi- nence and the beak; in fact, it is either straight or simply curved. The pigment fleck is usually rhomboidal and only occasionally oval, triangular or irregular. In other respects the agreement is rather close; the terminal claws have two series of spines, one of which is larger (not, as said by Birge, equal); the outer series is not so much larger as in S. rostratus, but not nearly as inconspicuous as in S. vetulus. ‘The terminal claws are rather evenly curved. This species is frequently colored with pink or brown markings. In old females the back is squarely angled above, forming a pocket for the eggs. The size falls short of that of the last speeies. I have found this species from the Gulf of Mexico to Minnesota. Professor Birge now recognizes this as S. serrulatus. *Simocephalus rostratus Herrick. Herrick ’84. This form is of the size and color of S. americanus, and approaches nearest to Schoedler’s S. exspinosus in general characters. The back is arched above but not abruptly angled; the spine is as in S. americanus but notsolow. The free posterior shell margins are somewhat shorter 12 180 © GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. than the greatest height of the shell. The head is produced below the eyes in an angle like a right angle, which is not spiny. The lower margin of the head is excavated to form a right angle, and in front of the smooth antennules forms a very prominent beak, beyond which the antennules reach but a short distance. The terminal claws of the post-abdomen are straightish and are more heavily spined than in the preceding; the anal spines are doubly curved or geniculate. The pigment fleck is rhomboid or pentagonal; the antennules are smooth. The abdominal processes differ somewhat from the previous species, in which the second one is rounded above, for in this it is squarely truncate. This species was found only in shallow pools at Ocean Springs, Miss., and was very carefully compared with S. ameri- canus, which is also found there. Simocephalus exspinosus Koch. Head extending into an obtuse angle at the eye, pigment fleck rhomboidal. Shell without a spine; maximum height of the shell greater than that of the free posterior margin. Caudal claws with an unequal series of spines; anal spines evenly curved. There is little to distinguish the above from this species save the geniculate anal Spines and the presence of a blunt spine on the shell, Var. congener Schoedler has the lower outline of the head sinuate instead of angled. * Simocephalus daphnoides Herrick. PLATE XLVI, Fias. 5,6. Herrick ’83. A curious transition form, found only south of the Tennessee river, was described in the American Naturalist for May, 1883, under this name. By an oversight a comparison made with S. americanus ap- peared as though made with S. vetulus. The general shape is oval; the greatest height of the valves lies near the middle and not posterior to it as in all the other species. The head is short, depressed, rounded in front; the beak is wanting; the lower margin of the head is straight. The pigment fleck is small, oval or irregular; the fornices are small and short. The antennules are smooth. The post-abdomen is narrow, shaped more as in Dane the ter- minal claws are straightish and fringed part way with spines; the anal Spines are slightly curved. The processes of the abdomen are long, as in Daphnia. The shell is covered by the characteristic striations and extend into a blunt spine. In every detail, almost, there is an ap- proach toward the genus Daphnia, while the general result is suffi- Le y ete eS ge i i aed? gine NY ea ee gy ene tad I ee te Te ie ae Rae id ae SME WA . ea ts ie a) “ r 7 ri edt ‘uF & ae Soy / , ate + Di ‘ " ENTOMOSTRACA OF MINNESOTA. 181 ciently Ilke Simocephalus. The lower angle of the shell is not armed with the peculiar curved spines as in all the other species. This species becomes over one-tenth inch long. In such old individuals the spine is nearly midway of the height. One could wish a trifle closer link to Scapholeberis than that furnished by S. angulata; but, on the whole, the position of this genus can not well be called in question. America has four species out of the six known and but one of these certainly identical with the European, though others are probably closely related. GENUS DAPHNIA. Long considered the type of the family, this genus is most frequently seen, or, at least, is more conspicuous than any other group. It has already been pointed out that the forms here united are the extreme development of a diverging line. Simocephalus is the link connecting it with the typical forms of the family. As might be expected, this genus presents more puzzling problems than any of the others. It con- tains more peculiarities of structure and diversities of habit and de- velopment than any other of the genera. Here the sexual differences are most interesting. The young are hatched with a pendant appendage attached to the upper posterior angle of the shell, which soon becomes the rigid spine characteristic of the younger stages and males of the genus. The females almost immediately after birth commence the production of eggs by an asexual process.’ Groups of epithelial cells containing four each are formed and one of the cells of each group develops at the expense of the others, forming the egg. Many such eggs are laid simultaneously and deposited in the cavity between the shell and the dorsal part of the animal. The eggs are prevented from escaping by means of three long processes, of which the first is much the larger and curves forward. At stated periods in spring and autumn the males appear; the females of the generation in which occur the males have a tendency to produce eggs of a different sort charged with a different mission. At the same time the upper portion of the shell (that surrounding the brood cavity) becomes finely reticulated and pigment is deposited between its layers. This ephippium, as it is called, in allusion to its saddle-like form, is the case in which the winter egg is to pass the period of cold or drought which is to follow. The method of the formation of the ephippium is obscure and, in spite of the investigations of Lubbock and Smitt, considerable remains to be learned with reference to this interesting modification of the shell. Some rather careful study has been devoted to this subject by the writer, but it was unfortunately interrupted before completion. The gf 7. es et ee Le NF ee eee 182 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. most promising method of pursuing the investigation is that of sectioning ephippial females in various stages with the microtome. A preparation of soap was employed with partial success as a medium for embedding. Development of Daphnia. Although the careful researches of Claus and Grobben have added much to our otherwise rather meager knowledge of the development of the Cladocera, there still remain many interesting points, particu- larly with reference to the individual species, which merit careful study. The following observations relate to the single species D. scheffert which was available during a short stay in Leipzig. The winter eggs of D. schefferi are two in number and are lodged in the well known manner in an ephippium. The shape of these eggs is sharply ovoid, there being no distin- guishable difference between the two ends. The position in the ephippium is not, as might be expected, with the longer diameter parallel to the axis of the body, but the posterior end is slightly ele- vated. This is undoubtedly due to frequent elevation of the abdomen between the valves during the extrusion of the eggs. The color is dark green and the only protection as the egg leaves the ovary is a thick, tough shell which is at first so soft as to be sus- ceptible to pressure. It is thus reticulated, apparently through the Simple pressure of the walls of the ephippium. The length is 0.43 mm.; width 0.33 mm. in the average, though eggs were occasionally found of an elongated form, measuring 0.48, 0.31 mm. The contents of the egg consist of spheres of greenish plasma of various sizes and fat or oil drops. These oil globules are not very numerous as compared with those of the summer eggs, and likewise never attain the dominant size seen in the latter. The various forms assumed by the plasma balls are perplexing but frequently result from the action of external agents. The cleavage stage was not seen, and if actual segmentation takes place, it must be inconspicuous as would be expected from the large quantity of yolk present. The differentiation of the blastoderm occurs very early, perhaps in the ovary itself, and the result is a tolerably uniform layer of prismatic cells. The egg now comes to a period of repose after the blastoderm has produced a second external envelope apparently by simple secretion. This envelope consists of a fine structureless membrane. The egg, under ordinary circumstances, remains dormant during the winter in this most favorable stage. The reason for which is evidently the fact ENTOMOSTRACA OF MINNESOTA. 183. that the differentiation has proceeded to the extent of producing the greatest number of protective layers without materially increasing the complexity, and thus the sensitiveness, of the organism. Under favor- able circumstances the development proceeds farther and near one pole appears a slight indenture of the surface which grows deeper and seems to form a true invagination. This blastopore, if such it really be, remains for some time, generally till the two ‘‘Scheitel’’ plates appear. These ‘‘Scheitelplatte’’ are formed by asimultaneous thick- ening and lengthening of the cells of limited areas on opposite sides of the egg, near the opposite pole from that occupied by the blastopore. The ‘‘Scheitelplatte’’ are situated at right angles to a plane perpen- dicular to the blastopore. The nuclei of the cells of the ‘‘Scheitel- platte”’ are nearly 0.0208 mm. in diameter, while those of the other blastoderm cells are about half that size. The egg remains a long time in this stage, while the following stages are passed through quite rapidly till the embryo assumes its nauplius form. The remainder of the development agrees, so far as. seen, quite fully with that of the summer eggs, to which we will now return. The summer eggs vary greatly in size and number, but are nearly as large as the winter eggs. The number is sometimes reduced to two or three or rises to as many as fifteen or even more. In color the eggs vary from green to brown. The fresh egg consists, as the winter egg, of two sorts of yolk spheres. The plasma or formative yolk con- tains colored globules of rather small size, distributed throughout the whole of the mass quite uniformly. The food yolk or oil globules assort themselves in two sizes; first, a few (generally three) very large oil drops, which persist throughout the earlier stages of the embryo; second, smaller globules of apparently the same character, which are quite numerous and form a very considerable part of the contents of the egg. Inan egg of about 0.35 mm. in diameter, the largest of the smaller size of oil drops measured 0.029 mm., while the larger three exceeded 0.060 mm. ‘The oil drops are distinguishable by their light refractive power, pellucidity and the intense dark brown or black color assumed when treated with osmic acid. The latter reagent affects the formative yolk but slightly. It will be seen that though the summer egg is nearly as large as the ‘‘Dauerei’”’ in some cases, yet the relative amount of formative yolk is more diverse than at first appears. The great similarity between the two sorts of eggs in Daphnia schefferi is throughout striking as compared with Moina, the only one of the Daphnide the development of which is fully studied. In the summer eggs I have not been able to see the complete segmentation hee A Ln able tr An Metres ives Yl Mg 184 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. described for Moina. The following stages are much as described by Grobben. An invagination occurs and a median swelling appears on the ventral aspect of the egg. Labrum and second antenn bud out and are soon followed by the antenn, mandibles and two pairs of maxille, after which the five pairs of feet soon appear. In an early stage there is present a basal palpus to the second antenne, a fact not before observed, and this per- sists as the small two-bristled wart found on the basal joint of the an- tenna. It is a conspicuous object in the embryo and is thus a true embryonic organ. The eyes of the embryo appear as two separate pigmented flecks which approximate and are covered with an oval refractive body, which later is penetrated by the pigment and divides to form the small lenses. Soon after this the shell grows over the eye as described for Moina. The first indication of the shell appears as two folds of the maxil- lary region of the back, being thickest laterally. These grow forward and backward to form the cephalic and body shield. At a little later stage there appears a very interesting modification of the shell which stands in close relation to the growth of the brood sac. A slight pro- tuberance appears on the margin of the shell in the median dorsal line and extends toward the abdomen. It grows much more rapidly than the other parts of the shell and, in a later stage, forms a compara- tively enormous tail, which curves under the animal between the shell valves which now extend beyond the body. This ‘‘tail’’ extends well along the ventral margin of the shell and reminds, by its posi- tion, of the tail of a frightened dog. The true tail, or post-abdomen, is, in the meanwhile, well developed and is constantly kicking the useless protuberance of the shell upwards. As the animal leaves the egg this projection becomes straightened as in the young D. pulea, finally becoming the still considerable spine, though it is proportion- ately much shorter than in the embryo. The spine becomes shorter with successive moults, and the mature form has only a slight rounded knob in place of a spine more than half the length of the body. The use of the long spine in the young Daphnia is a matter of in- terest. Its length agrees pretty well with that of the brood cavity and it seems possible that it serves to prevent the shell from bending abruptly down when it is only partially removed during the moult and thus breaking off and so leaving a portion of the clothing of the brood cavity therein to become a source of irritation, This is more necessary for the young, since the brood cavity is narrow and the shell weak, so that while the outer shell is removed like a glove from the finger, it cannot be pulled upward or downward, but directly eae ee ee NT, | gre Vr Cr Ne ene Sy oY OP ‘ eS : “s , ENTOMOSTRACA OF MINNESOTA. 185 backwards. It is well known that male Daphnie often have the spine while the females may have none, and here again it is possible that the narrower cavity over the abdomen requires this assistance, while this is not the case with the females. The shell gland is early formed and the branchial lamelle of the feet appear almost simultaneously with the feet themselves as distinct lobes. The branchial chamber is not a simple chamber, but is essen- tially a curved tube, as can be very well seen in the last foot of the adult. This tube doubles upon itself and crosses in the manner of a loop and a constant stream flows rapidly through it. The nervous system is, at first, paired from beginning to end and first unites anteriorly, the ocular ganglia fuse after the union of the two pigment flecks in the compound eye, then the cephalic ganglion is formed by the union of the two precesophageal ganglia, and the com- missures passing about the cesophagus. I have not been able to de- termine if the subcesophageal ganglia become fused. From the anterior ganglia spring the nerves to the oe and jaws, which latter are larger in the embryo. It is greatly to be regretted that no sufficient revision of Daphnia can now be attempted. This is partly due to the very imperfect nature of the descriptions and partly to the scattered literature of the group. We here supply nothing more than a provisional key and synoptical descriptions. I take pleasure in acknowledging the substantial assistance, in respect to recent literature of the group, received from my friend, Professor Birge, as also for valuable sugges- tions respecting Cladocera in general. KEY TO THE GENUS DAPHNIA. I. Pigment spot present. A. Anal margin of the post-abdomen deeply excavated. . . Schaefferi, 187 Bb, Anal margin slightly if at all sinuous. a. Head very short and Bea es curved from the heart to the beaks ie sees . . psittacea, 187; atkinsonii, 188 b. Head not very Short or eeedlacly curved. * Claws of post-abdomen with a distinct comb of spines. { A strong toothed process from the dorsal margin of the head at some time of life. t Spine long, straight. . . . . . . . . @lathrata, 188 ti Spine short, curved. . . . . . minnehaha, 189 tt No strongly toothed dorsal process a any period in either sex. { Head with azhelmet-like crest. % Spine long, springing from the dorsal angle, CULVCR GOTSICs se ia: Hrak oa wang Peer eh OR TISs LOO 186 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. 22 Spine moderate, springing from the middle of the caudal margin. . . .. . . . arcuata, 190 tt Head uncrested. @ Spine short or absent. || Abdominal process united at the base. . gibbosa, 191 |||| Abdominal processes discrete. { Spine near the middle of the caudal margin. ° Anal teeth 20 to22. . .:. ... . Ovata, 19% 9° "Anal teeth 9 to 10... .+%. 52... =>, QObiusa, ie {| Spine at the dorsal angle. So ae ea pina, 192 2% Spine of considerable length. || Spine near the middle of the caudal margin. | Ventral margin of the head convex. . hastata, 192 {| Ventral margin of head concave. ° Eye distant from the margin of the heaa? 5: ee tees: ie ee ORMED bare lo °° Eye near the margin of the head. x Abdominal processes united at the base. soe Se 5 Sehoedieriiass xx Abdominal processes discrete. brevispina, 193 \||| Spine nearer the dorsalangle. . . . . pulex, 193 ** Claws of the post-abdomen without a basal comb of teeth. + Antennal sete thick, first segment longer than the second. { Spine near the middle of the caudal margin. ventricosa, 195. tt Spine above the middle of the caudal margin. . caudata, 195 +t Antennal setz with the second segment longer than the first. { Headhelmeted. = 6)C25° 6 Poe, ss 2 eV tt Head not helmeted. 2 Abdominal processes united. || Dorsal margin strongly carinate. . . . . Sarsii, 198 \\\| Dorsal margin slightly or not carinate. ‘| First abdominal process much the longer. ° A deep depression separating head and body. © oss. ats) (paludicolasies °° Avery slight depression separating head and body. longispina,199; minnesotensis,199 { Abdominal processes nearly equal. oul ° Anal claws 12 to22. . . . . cGavifrons, 200 °° Anal claws 7 to 23. . . . microcephala, 200 22, Abdominal processes discrete. || Abdominal processes short, equal. . . . rosea, 20 |||| First abdominal process twice as long as the second. ; Beak not greatly produced ventrad. . aquilina, 200 {{ Beak greatly produced ventrad. . . lacustris, 201 tit Head with a dorsal toothed crest. 2 Crest just in frontofthe heart. . . . . dentata, 201 22 Crest over the bases ofthe antenne. . . dentifera, 202 II. Pigment spot absent. A. Head not helmeted or but slightlyso. . . . . . . longiremis, 202 B. Head helmeted. ENTOMOSTRACA OF MINNESOTA. 187 a. Eye near the end of the head. Sheet lake. ie) Mag iiCepSs, 202: b. Eye not near the end of the head. * Abdominal processes free. . . . . . . #£=Kalbergensis, 203 ** Abdominal processes united. Hela Ae wig asus op CUCULAtA, 205 [Not in the key: dubia, 196; pennata and curvirostris, 194; thorata,197; hermani, 198; similis, 204; bolivarl, 205; carinata, 205; lumholtzii, 206. ] Daphnia scheefferi Baird. PLATE LI, Fiaes. 1-5. Daphnia pennata — Mueller. Daphnia pulec—Straus, Koch (fide P. E. Mueller). Daphnia magna—Lilljeborg, Leydig, etc. The largest species of the genus, is of an elongated oval and ven- tricose form. The head is short and evenly rounded, The spine is. entirely absent in old females and of only moderate length in the young. The antennules of the male are long and have a very long flagellum. The post-abdomen is narrowed suddenly below the anus so that the spines consist of two sets; the terminal claws are spiny at the base. The species may be recognized at once by the concavity of the dorsal margin of the post-abdomen. The plate will make any de- tailed description superfluous. A common species in Europe, but not yet found in America, The sole distinction between this species and D. magna Straus is found in the fact that the intestinal cceca are very long and recurved in D. schefferi and short and thickened at the free extremity in D. magna. We fail to discover sufficient reason for separating them. Daphnia psittacea Baird. Baird ’50; Schoedler 758; Fric’72!; Kurz’74; Hellich’77; Herrick ’84; E!ymann’87; Daday ’&8. Head short, rounded in front, beak very short. A depression sepa- rates the head from the oval, ventricose body. Spine long directed dorsad. Eye distant from the margin of the head. Post-abdomen long, narrowed toward the end, somewhat sinuous in the caudal margin. Anal teeth about ten. Claw bipectinate, rather long. Length 1.8 to 1.9 mm. This species is at once recognized by the head, which is very short and evenly curved, or nearly so, from the heart to the beak. The shell is high, oval, with a rather short spine. The fornices are wide and angled behind. The antennules are longer than in most species; the post-abdomen is very large, but narrows toward the end and has comparatively few anal teeth, which are of unequal size. This is one of the largest of the genus. Not yet found in America. 188 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. Daphnia atkinsonii Baird appears to us but a variety of this species. There is said to be no depression between head and body and the anal teeth diminish dorsad instead of being nearly equal as in D. psittacea. Considerable disagreement exists in the various descriptions. Daday’s figures show no grounds for separating the species. * Daphnia clathrata Forbes. Forbes ’93. ‘A species of moderate size, with short, deep head, medium to very long posterior spine, minute pigment fleck, and pectinate tarsal claw. In the immature female there is a prominent angle just above the swimming antenne, like that of D. dentifera. In the adult female the head, measured vertically across the rostrum, is twice as deep as its length from the base of the antenne to the middle of the front. It is sharply keeled rather than crested, very broadly rounded, its lower margin very slightly convex or quite straight, and its rostrum well marked in the adult. The eye is close to the front, the transparent orbit reaching to the margin of the head, of medium dimensions, its antero-posterior diameter contained twice in the space between the posterior margin of the head. The pigment speck is very minute, placed behind the lower half of the eye and nearer the posterior margin of the head. The fornices are not prominent. Beginning midway between the antenna and the eye, they arch broadly above the base of the former, making an obtuse angle a little beyond the antenna, and continuing as a slight carina backwards and downwards for a little dis- tance on the side of the valve. ‘*The ventral margin of the shell is more broadly arched than the dorsal, the latter being in the immature female nearly straight from the heart backwards. The valves are conspicuously quadrangularly reticulate, spinose on their lower edges nearly to the beak, and on the upper edge to the vicinity of the heart. The posterior spine is very long, straight, slender, spinose to the tip, contained in average cases not more than twice in the length of head and body without the spine. ‘‘The antenne are rather short, about half as long as the distance from the posterior margin of the eye to the base of the posterior spine. The swimming hairs are two-jointed, the basal joint the shorter. The dorsal abdominal processes arise in immediate connection, but are not united at their base. The anal furrow has about a dozen teeth on each side, and the caudal claw has a comb of three or four conspicuous teeth at its base besides a little group of smaller ones. Length of ovigerous female 1.7 mm. to the base of the spine; the greatest depth 0.85 mm. The male not seen. Occasional in Grebe lake, Yellowstone Park.” WEEE RR ey ee ee mie AN ee OR ee gh doe YN ge - hy "\ ae ENTOMOSTRACA OF MINNESOTA. 189 *Daphnia minnehaha Herrick. PLATES XLIX, Fies. 1, 2a; L, Fies. 1, 2; LII, Frias. 1-3. Herrick ’84; Birge ’91. This species, which occurs in small pools in autumn (affluents of Minnehaha creek, etc.,) closely corresponds apparently to Sars’ Daphnia carinata but differs in numerous points. It, in fact, is more nearly related to D. pulex than the group under which that species is placed. The form is oval, arched above, narrowed posteriorly, terminating in a rather short spine which curves lightly upwards. In males and young females the spine springs from the upper angle, but in old females having many summer eggs the spine is nearly median. The head is depressed, strongly arched and keeled slightly above the eye, which occupies the extreme end of the forehead. The keel of the head extends into a slight angle over the heart and continues down the back. In young females and in males the slight angle is replaced by a strong knife-like projection which extends into from one to four sharp teeth, the anterior tooth being directed forward. The males, in particular, have this feature emphasized. JD. longispina has a somewhat similar projection, but the more nearly related forms seem not to show this peculiarity. The beak is slightly curved and the lower margin of the head is slightly sinuate. The shell has the usual square reticulations and is usually very transparent but in peaty waters becomes brownish. The size is small but variable; 1.8 mm. is a common measurement. The post-abdomen is narrow, the claws are armed with four or more teeth and a series of lateral bristles. The anal spines are eleven or more in full grown females and decrease only moderately upward. The processes of the abdomen are distinct. The males are smaller and strongly carinated above and of the same form as young females. The antennules are rather long, with a short lateral and a long terminal flagellum, which latter is more than twice the length of sensory setz which are partially lateral. The first foot has a strong claw and a long flagellum, while the second feet have a small spiny hook. There is a Single abdominal process which is not hairy as in D. pulea. The following measurements may be added: Female—Length 1.44 mm., spine 0.33 mm., head 0.26 mm., depth of head 0.46 mm. Male—Length 1.0 mm., spine 0.17 mm., head 0.20 mm., depth of head 0.31 mm., length of flagellum of first foot 0.35 mm. Ephippial female —Length 1.64 mm., spine 0.20 mm., head 0.385 mm., depth of head 0.8 mm., greatest depth of shell 0.94 mm. The ephippial females appear in July in the vicinity of Minneapo- lis, and at that time it is rare to find a female with the toothed crest developed. D. dentifera Forbes is closely related but has smooth claws. 190 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. * Daphina exilis sp. n.? PLATE LII, Fias. 4, 5. It is admittedly undesirable to describe a specimen instead of a species, but the form for which the above name is provisionally pro- posed is so peculiar and its locality so little studied that a description is given based on a single young female. It will be understood that the ovigerous female would differ in the length and position of the Spine, size of crest and form of the abdominal processes. A daphnid of moderate size with crested head, long spine and den- tate caudal claw. Nearly colorless. Head projecting in the line of the axis of the body, crested from the eye to a point cephalad of the heart, but truncate in front. Ventral outline nearly straight, beak not projecting, antennules very short and applied almost at the end of the beak, which does not lie between the valves. Eye of rather large size, with few crystallines, near the ventral margin. Pigment fleck small, nearer to the caudal margin of the head than to the eye.. Coeca narrow, strongly curved, Antenne short and stout, second segment of the sete longer than the basal. Fornix moderate. Valves sub-oval, strongly curved ventrally, dorsal outline straight from in front of the heart to the spine, which is very long and curved dorsad. In this specimen the spine is longer than the entire valve. There is no dorsal emargination between the head and body. Dorsal margin armed with spines beyond the heart, ventral margin spined more than half of the length. Valves marked with the usual quadrangular meshes. Post-abdomen narrowed toward the end. Anal margin sin- uate. Anal teeth about eight, nearly equal. Claw short and moder- ately curved, armed with a continuous series of spinules and a comb of fine spines near the base. Length, exclusive of spine, 1.15 mm.; length of head 0.38 mm., height of head 0.54 mm., height of shell 0.65. mm., length of spine 0.84 mm., diameter of eye 0.10 mm, length of base of antennze 0.26 mm., claw 0.09 mm. The abdominal processes in this specimen are not in their mature form. It is not certain that the dense hairiness of the anal margin above the teeth is an adult. character. It would appear that the crest is normally a strongly pro- jecting cephalic helmet, but this is but conjectural. Found in weedy pools fed by irrigation canals at Albuquerque. * Daphnia arcuata Forbes. Forbes 793. ‘‘Head helmeted, rounded in front, length one-third that of the shell, front concave, beak produced, extending beyond the sensory hairs of the antennz. Eye small, about midway between the mandi- ENTOMOSTRACA OF MINNESOTA. 191 bles and the front of the head, and about midway between the tip of the beak and the dorsal surface of the head. Pigment speck very small, less than half the diameter of a lense of the eye, and placed midway between the eye and the posterior margin of the head. The latter concave, the beak extended backward and applied against the margin of the shell. Swimming antennz reaching the middle of the shell, their hairs moderately robust, the first segment not longer than the second. No emargination separating head from'‘body, but the dorsal surface very slightly sinuate there. Abdominal processes all distinct, anterior much the longest. Caudal claw with accessory teeth, about six in number, the three proximal the largest. Anal spines about ten. Posterior spine of the shell given off from the middle of the valves, in the adult female a third to a half as long as the valve. Shell moderately coarsely marked in quadrangular areas, the lower and dorsal margins spinulose from the middle backwards. Length 2.0 mm., depth 1.0 mm. Heart Lake, Yellowstone Park.”’ Daphnia gibbosa Hellich. Hellich ’74 and ’77; Elymann ’87. Body large, very high. Head depressed, ventral margin strongly concave. Eye large, with few crystallines. Antenne long, scaly. An obvious depression separates head and body. Spine short, above the middle. Abdominal processes united. Anal teeth 17 to 19, dimin- ishing dorsad. Claws with a comb of teeth. Color reddish. Length 2.01 mm. Daphnia ovata Sars. ‘*Caput a latere visum ante oculum fere angulatum, margine inferiore leviter con ‘cavo in rostrum longum apicem versus attenuatum, extremitate tenuissima exeunte- spura visum ut in D. pennata cordiforme. Testa cetera a latere visa ovata, margine superiore et inferiore in femina adulta fere sequzs arcuatis, postice in medio spinam formans brevissimam vel omnino obsoletam. Processus anteriores duo abdominis dis- juncti. Margo posterior postabdominis in medio sinuatus, utrinque aculeis 20-22 armatus. Color albido—flavescens vel-virescens. Longit. circit 3 mm.’’ No one besides Sars seems to have seen this species. We suspect it is simply D. schefferi. Daphnia obtusa Kurz. Lilljeborg ’53 (pulex); Kurz ’74; Hellich ’77; Elymann ’87; Daday ’88. Head short, front rounded, ventral margin slightly sinuate, beak short, acute turned caudad. Eye remote from the margin of head. Crest absent. Body oval, margins convex, spine nearly absent. Post- Fi LS NE RN, OL Lh ae Semi |e en a ce : ; ui Pst Fy ueen wan Cao oc 192 GEOL, AND NAT. HIST. SURVEY OF MINNESOTA. | abdomen not ciliate, of moderate size. Anal teeth 10, nearly equal. Claws bipectinate. Abdominal processes discrete. Length 1.08 mm. It still seems probable that this is an age form of some species with longer spine. Daphnia alpina Daday. Daday ’88. Head short, somewhat produced ventrad, front rounded, ventral margin almost straight; beak rather acute, short, extending ventrad. Eye large, rather remote from the margin of the head. No crest. Shell almost round, ventral margin obviously rounded; spine absent or very short, simply forming an acute angle. Post-abdomen small, laterally setose, bearing 11 to 12 anal spines which are short and curved and slightly diminish in size dorsad. Claw with a comb of long teeth and a continuous series of fine spinules. Abdominal pro- cesses discrete. Length 1.2 to 1.9 mm., depth 0.9 to 1.15 mm. The resemblance to D. obtusa Kurz is very close, but that species has the sides of the post-abdomen smooth, the ventral margin of the head concave and the spine near the middle of the caudal margin of _ the shell. The shell is longer and more oval in outline. Weshould | wish to be very sure that these are not both old individuals of a spe. cies having the usual spine in younger stages. Daphnia hastata Sars. A large species of reddish color, with strongly depressed head, whose ventral margin is convex. Shell oval, with along spine. The abdominal processes are long and approximate. Anal spines Ilo. Length 3.0 mm. This species was inadequately described by Sars and probably should be dropped. Daphnia ornata Daday. Daday ’84! (serrulata); ’88. Head not separated by a depression from the thorax. Beak rather acute, short, turned ventrad. Eye distant from the margin of the head. Shell oval, margins rounded, with a moderate spine directed caudad. Post-abdomen scarcely attenuated apically with eight to ten curved anal spines, diminishing dorsad; sides setose. Claw with a basal series of spines and a continuous series of fine sete. Abdominal processes discrete, ciliate. Length 1.0 to 1.5 mm., height 0.85 to 1.0 mm. The ventral margin of the head in this species is more curved than in D. alpina, and this might well be a younger form of D. obtusa, though the sete on the sides of the abdomen are not noted in that spectes. RMTRT GEOTN MES fo ee a Le Men by ip aR Ae 7 \ 7 ENTOMOSTRACA OF MINNESOTA. 193 Daphnia schoedleri Sars. . Schoedler ’58 (longispina); Sars ’61; Hellich 77; Elymann ’§7; Daday ’88. Head arched in front, ventral margin gently sinuous, beak acute, projecting ventrad. Lye large, near the margin of the head. Body oval, spine long. Post-abdomen of moderate size, with 12 [14 to 16] anal teeth. Claw with comb of spines. Abdominal processes discrete but approximate [Daday] or distant from each other [Elymann]. There is wide disagreement between the various descriptions of this species. Daphnia brevispina Daday. Daday ’88. Head short, slightly projecting ventrad, front strongly rounded, ventral margin somewhat sinuate. Beak short, acute, inclined ven- trad. Eye distant from the frontal margin of the head. Shell oval, with a slight depression between head and thorax, margins arcuate, with a very short spine. No crest. Post-abdomen rather long with delicate lateral sete; anal teeth 12, curved, almost equal. Claw with a comb of spines and a continuous series of fine sete. Abdominal processes discrete, setose. Length 1.2 to 1.8 mm., height 0.75 to 1.2 mm. * Daphnia pulex De Geer. De Geer 1778; Hellich ’77; Lutz ’78 and ’79; Elymann ’86; Daday ’88, Matile ’90. Body large, stout and thick, rather opaque, reddish. Head broad, depressed, front protuberant. Ventral margin of head deeply con- cave. Beak acute, curved backward. Fornix high. Eye small, with few lenses. Antennules short, conical, extending but little beyond the beak. Antenne short, slender, evidently marked with scuta, with long densely pectinate sete. The shell is not separated from the head by a depression in mature females and is oval in outline. The ventral margin is much more strongly arched than the dorsal. Spine very short, straight, inclined upward and inserted above the middle of the posterior margin. Shell margins with short spines. Surface reticulate in fine quadrangles. Cceca short, clavate, curved dorsad. The abdominal processes approximate; the first twice as long as the second; the third small. Post-abdomen long, narrowed toward the end. Its distal end is rounded. Anal teeth 12 to 14, nearly equal. Claws curved, with two combs of teeth, the higher consisting of six to seven teeth, the lower of three to four. Length of female 2.15 mm., height 1.23 mm., spine 0.16 mm. It is at present impossible for the writer to unravel the relations of the numerous varieties and supposed species of the pulex group. Probably most of them are simple Syno- nyms. The following American varieties may be mentioned: 194 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. © * Daphnia pulex var. denticulata Birge. The lower margin of the head is said to be less convex [concave?] than D. pulex. The abdominal processes are less hairy, there is a continuous series of spinules on the claw and a larger number of anal spines—18 to 20. Daday figures claws such as Birge describes. * Daphnia pulex var. nasutus Herrick. PLATE XXXV, Fias. 1-4. This in some respects is more like the type. It has an elongate oval form with spine of variable length arising from above the middle. ‘The impression between head and body is slight. The ventral margin of the head is concave and the beak is curved caudad. The terminal claw of the post-abdomen is furnished with two combs of fine teeth. ‘The anal spines are 10 to 14. The abdominal processes are hairy. Neither this variety nor the above seems to possess the two teeth on the front margin of the claw. * Daphnia pulex var. pulicaria Forbes. This seems to closely resemble the type. The fact that the antennsz are ornamented with spines rather than scales is noticed. The first abdominal process is smooth, as it is also stated to be in the European form by some authors. The male is said to differ more, but compari- son of Forbes’ figure with that of Elymann reveals nothing of impor- tance. (Elymann figures spines rather than scales on the base of the antenne of the female.) [Daphnia pennata Sars. ] ‘‘Antecedenti (D. pulex) simillima, caput autem a latere visum latius, rostro bre- ‘viore, supra visum testa cetera parum angustius fere cordiforme, antice acuminatum. Processus anteriores duo disjuncti. Margo pusterior postabdominis in medio sinulo parvo et infra hune utrinque aculeis 16-18 armatus. Color ut in antecedente. Longit ‘0.24 mm.”’ Although admittedly very close to D. pulex, it is said to differ in the broad depressed head, which is uniformly rounded in front and deeply excavated in front of the beak, which is short and deflected. The post-abdomen has 16 to 18teeth. The antennules of the male are almost as long as the head, bearing a long pointed flagellum and a short lateral seta. [Daphnia curvirostris Elymann. ] The differences relied on to distinguish this species from D. pulex seem to us quite inadequate. The head is more depressed and this gives to it a quite different appearance. The male antennule is thick- ened slightly at the middle and the flagellum is longer. The hairy abdominal process is absent. ENTOMOSTRACA OF MINNESOTA. 195 Daphnia ventricosa Hellich. Hellich ’77; Elymann ’87. A large pelagic species without the toothed comb of the claw. The head is depressed, small, with rather protuberant front and long beak inclined caudo-ventrad. The short oval shell is deeper than the head, well rounded above and below. Spine long and straight, springing from the middle of the caudal margiti. The antennal sete are short and thick and have the first segment longer than the second. The first abdominal process is twice as long as the second, with which it is united. The post-abdomen narrows toward the end and is hairy lat- erally. Anal spines14. Claws with sete. Length 2.28 mm. Daphnia caudata Sars. Fischer ’54 (longispina). A large species without basal spines upon the claws. Head some- what depressed, about one-third as long as the body, ventral margin slightly concave; beak long, inclined caudo-ventrad. Shell oval, with no depression between body and head. Spine long, springing from the middle of the caudal margin. Eye near margin of head, with few crystallines. Antenne with short thick sete whose basa} segment is longer than the second. Post-abdomen narrowed toward the end. Anal spines 9 to 12. Claw with a row of sete on the con- cave, and two spines on the convex aspect. The two cephalic abdominal processes united. Length 2.3 to 2.67 mm. This species is said to resemble D. longispina. It would appear to be closely related to D. ventricosa. * Daphina hyalina Leydig. PLATES XXII, Fies. 7, 8; X XVII, Fic. 6; XXXV, Fia. 16; XLIX, Fies. 3-5; LILI, Fies. 1-4. Leydig ’60; Sars ’64 (galeata); Hellich ’74 (gracilis); P. E. Mueller ’68 (pellucida); Birge ’78 (levis); Herrick ’&3 The general form and appearance down to the minute details in this species are similar to D. kahlbergensis, with which it is almost always associated, except the head which is subject to an astonishing range of variation. A comparison of Figs 1 and 5 of Plate LIII, which were drawn by camera upon the same slide, illustrates the simi- larity. The body is pellucid. Shell, sub-oval, with long, straight, toothed spine as long as the body without the head, and inserted high up. Post-abdomen narrow with discrete processes, anal teeth about ten, terminal claw finely fringed or smooth. Eye small, either near 13 196 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. the margin and occasioning a prominence in the ventral outline or retreating from it. Macula nigra small or almost non pigmented. Gastric ccecca slender, Antenne weak. The typical form of head is that of Fig. 3, Plate LIII, but the outline may be evenly rounded. The range of variation is well shown by the various figures. The young have no horn on the head. The spine of the shell is nearly as long as the whole animal in the young. The male of our form is 1.2 mm. long, excluding the spine which measures 0.47 mm. The flagellum is a very little longer than the sensory sete, and there is a very minute lateral flagellum. A peculiarity of this species is the scattered thorny armature of the spine of the shell. There is but little change in the form of head with age. The form of the last feet is peculiar. The ephippium occupies comparatively a small part of the valves and the spine becomes very short and quite smooth. The sexual period occurs in September and October. (* Daphnia dubia Herrick.) PLATE XLIX, Fias. 7, 8. Our D. dubia may prove distinct. It is nearly related to D. hyalina, but the head is strongly crested all around and the eye is withdrawn, in young as well as old specimens, toward the middle of the head. This pecuiiarity is shared in this degree by no other Daphnia. The form is as in D. pellucida, but the spine is more slender and directed upward. The head is shaped much as in D. vitrea in the young, but is much less prominent. The older form has a shorter and more slender spine (none were seen in the ultimate or spineless stage). The head is more evenly rounded, but still well crested. The abdomen is very Slender and the anal teeth diminish rapidly in size from below upward. The claws are very short and armed down the whole length with fine bristles. The abdominal processes are well united at the base in old specimens, so that the second seems a small process of the first. The shell is very transparent and the spine is very long. Ina young specimen the spine was 1.0 mm., the body 0.7 mm., and the head 0.4 mm. In this specimen the spine was slightly curved, the head elongate with a slight ridge in front. Another individual had the spine 1.1 mm. long, while the remainder of the animal was 1.3 mm. This specimen also had a knife-like hyaline ridge on the crest, which was obliquely truncate in front; it also had numerous summer embryos in the brood sac. The spine was perfectly straight and but slightly inclined upward. Older individuals have a rounded crest as figured and noridge. The spine is relatively somewhat shorter but much more slender. The characters which most clearly distinguish ENTOMOSTRACA OF MINNESOTA. 197 this species are the well crested head, which in young as well as sometimes older specimens has a median hyaline ridge, the with- drawal of the eye from the margin and the very long spine. It reseim- bles D. galeata in earlier stages. It is very much like D. levis or, in other words, is in the group of D. hyalina. This form has only been found in autumn, September to November, Lake St. Croix and Rich- field in Hennepin county. [*Daphnia thorata Forbes. ] Forkes 793. ‘‘This species belongs to the hyalina group, and may possibly be entitled only to varietal rank. The distinctness and constancy of its characters, however, in collections made by us in Flathead and Swan lakes in western Montana, and the number of minor points in which it differs from hyalina, as most recently described, lead me to distin- guish it as a specific form. ‘*Tt is oval in outline; the long and slender posterior spine is placed at or a trifle above the middle; the length of the head is about a third that of the valves of the shell excluding the spine, and there is no trace of dorsal emargination between head and body. ‘The head is narrowed toward the base and elongated forward in a way to give it the outline of a bell jar with a flaring base. Its front is broadly and ‘regularly rounded, its ventral margin usually conspicuously concave and closely like the dorsal, although occasionally the head is straight or convex beneath. The posterior margin is either straight or slightly concave, and the beak stands free from the front margin of the valves, and by its extension downward not only covers the antenne but reaches clearly beyond the tips of the sensory hairs. The eye is of medium size, placed far back of the front of the head and equidistant from the tip of the beak and the dorsal junction of the head and body. The pigment speck is of moderate size, placed directly behind the eye, and much farther from it than from the posterior margin of the head. The antenne are moderately stout, entirely smooth except for inconspicuous transverse rows of minute appressed hairs upon both peduncle and rami, and a row of short, tooth-like spinules at the dis- tal end of each segment. The swimming hairs are rather slender, the second joint commonly decidedly shorter than the first. Fornices slight, arising above and a little behind the eye and terminating directly behind the antennz, above the bases of which they project but slightly. The lower margin of each valve is set with the usual spinules almost to the beak, and the dorsal margin is similarly armed for a distance in front of the spine about equal to half the length of 198 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. the latter. The valves are marked off by fine lines into large quad- rate meshes. The dorsal abdominal processes rise separately, the two anterior, however, in immediate contact at their bases. The first of these is decidedly the longer, but the third process is distinct, although low. The anal sete are two-jointed, the second joint the shorter. The abdomen is regularly narrowed backwards, and the anal groove is provided with twelve to fifteen teeth on each side, com- monly the latter number. The terminal claws are without accessory comb. The intestinal cceca are short, not longer than the diameter of the eye, and extend directly forward. Length 2.0 to 2.5 mm.; depth half the length, sometimes a little more. Length of spine variable, but commonly about equal to the depth of the shell.” As to the specific rank of this form we suspend judgment for the present. [Daphnia hermani Daday. | Daday ’88. Head broad, compressed, front rounded, beak round, projecting ventrad. Eyelarge. Macula nigra absent. Shell oval, with a long spine. Abdominal processes discrete. Claws without teeth but orna- mented with a continuous series of fine sete. Anal teeth six, dimin- ishing dorsad. Length 0.5 to 0.8 mm. This we may unhesitatingly regard as a form of D. hyalina. Daphnia sarsii Schoedler. Sars ’60 (carinata); Schoedler ’77; Elymann ’87 (carinata). A. large yellowish species with a strong dorsal keel. Head uni- formly curved, slightly concave behind the eye, with a long oblique beak. Dorsal and ventral margins curved. Spine short and curved, ‘springing from near the middle of the caudal margin- The abdominal processes long and united at the base. Claws without teeth. Length ‘2.5mm. The very insufficient description may help to place a form not recognized since Sars described it. When D. carinata King is finally placed among its congeners this ‘species will preoccupy Sars’ name. Daphnia paludicola Hellich. A large species of a dirty yellow color. Head depressed, front scarcely protuberant, ventral surface slightly concave, beak sharp, short. Antennules very small. Shell deep, oval, with a short curved spine springing from the middle of the caudal margin. First abdomi- nal process much longer than the second, to which it is fused. Post- ENTOMOSTRACA OF MINNESOTA. 199 abdomen small. Anal teeth 12 to 14. Claws with a series of fine sete. Length 2.18mm. In the male the lower margin of the head is excavated and the flagellum of the antennules short and straight. Daphnia longispina Mueller. Mueller 1785; Straus-Durckheim ’19-’20; Baird ’50 (pulex var. Jongispina); Leydig ’60; Sars ’61, and ’64 (affinis); Mueller ’68; Plateau ’70; Lund ’70-’71; Kurz 74; Hu- dendorff ’76; Hellich ’77; Lutz ’78 and ’79; Herrick ’84; Elymann ’87; Walter 788; Daday ’88; Matile ’90. A slender species of moderate size and transparent. Head not so deep as the body, from which it is not separated by a depression, slightly concave behind the eye. Beak long and directed caudo-ven- trad. Eye large, near the margin. Shell oval; spine long, situated above the middle line and curved upward. Two largest abdominal processes both directed cephalad and some- what united. Anal spines 10 to 12. Claws with a series of fine sete and two spines on the convex aspect. Length 2.0 to 2.5 mm. Flagellum of the male antennule hardly longer than the sensory sete. The young have three teeth above asin D. minnehaha. There is a great deal of diversity of opinion as to the value of this name. Not that there is any doubt of the existence of a widely dstributed form which in general is that intended by Leydig and others, but the variation is so great that the possibility remains that more than one species is included under the one title. P. E. Mueller recognizes two varieties depending chiefly upon the length of the spine. *Dapbnia minnesotensis sp. n. PLATE L, Fias. 10-12. Herrick ’84 (rosea.) The later descriptions of D. rosea leave no doubt that this is a distinct species. The abdominal processes are somewhat united at the base instead of ‘‘ manifeste discretis,’’ and the first is much longer. In many respects the species is near D. longispina. The original de- scription is given: ‘‘In form very like D. longispina, this species, which is the only representative of this smooth-clawed, unkeeled group yet found in America, might perhaps be appropriately united with that species. ‘“Body oval, moderately ventricose; head of moderate size, lower margin nearly straight; eye situatied in the anterior prominence. The beak is not very prominent. The upper outline of the head is slightly concave above the eye or rather less convex. The head is separated 200 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. from the body by a marked depression. The spine of the shell springs from the upper angle or is quite wanting. The post-abdomen is of moderate size, Somewhat narrowed toward the end. The claws are smooth, the anal spines nearly equal, straight, about fourteen in number. The abdominal processes are not coalesced or but slightly so. Length 1.50 mm. to 2.0 mm. The species was collected sparingly in a large gathering of D. pulex from a small lake in early spring. ‘‘The size and conformation of the abdominal processes are very variable and the long and very slender spine is frequently absent.’’ The antennules are very short. Males unknown. Daphnia microcephala Sars. A small transparent form, head only half as deep as the shell, slightly concave ventrally and ending in a short blunt beak. Shell elongate oval with a slender somewhat curved spine from the middle of the caudal margin. Abdominal processes nearly equal and united at the base. Analspinesseven. Claws without teeth. Length 0.75 mm. This is also a species requiring farther study. Daphnia cavifrons Sars. A reddish species with the head separated from the body by a depression, depressed, ventral border excavated, beak large. Shell ventricose with a short spine from near the upper angle. Abdominal processes nearly equal and united at the base. Anal teeth 12. Claw without teeth. Length 1.5 mm. I am not sure of this and the preceding. * Daphnia rosea Sars. Of moderate size, reddish in color, and resembling D. longispina. Head depressed and not separated by a depression from the thorax, somewhat excavated in the ventral margin, beak blunt. Shell oval, spine long, springing from above the middle and directed obliquely dorsad. The two abdominal processes thick, equal, discrete. Anal spines 12 to 14. Claw without teeth. Length 1.9 mm. The American form identified with this species is more like D. longispina. Daphnia aquilina Sars. A species of medium size, transparent. Head depressed, protuber- ant at the eye, excavated behind it, the beak lying in the same plane as the frontal projection and strongly curved caudad. LHye large. Shell oval, slightly separate from the head. Spine above the middle ENTOMOSTRACA OF MINNESOTA. 201 line very slender and short, directed dorsad. Abdominal processes long, approximate, the first twice as long as the second. Anal spines 16 to 17. Length 1.83 mm. Dapnia lacustris Sars. Very similar to D. aquilina and to D. rosea. The head is depressed and excavated behind the eye, the beak projecting ventrad below the fevel of the front. The eye retreats from the front and is large. The shell is oval and the spine is straight, springing from the mid- dle of the caudal margin. The abdominal processes are discrete but approximate. Post-abdomen as in D. longispina, with 14 to 16 teeth. Length 2.21 mm. This is doubtless to be reckoned among the varities of D. longispina. Daphnia dentata Matile. Matile ’90. I translate the description, 1. ec. p. 14. Body transparent. Head low and rounded cephalad; its ventral margin rather short and concave. Apex of beak directed ventrad [nach unten]. Antennal sete three-jointed, the last segment very short. Head separated from the thorax uniformly in adult animals by a tooth-like projection cephalad. Valves oval, extending into a rather short spine which lies somewhat dorsad of the median, longitudi- nal axis. Spine and the caudal half of ventral margins of the valves spined; dorsal edge without spines. Shell reticulated by regularly crossing lines. First two anal processes approximate and of equal length. Borders of the anal groove armed on either side with 12 to 14 Spines which diminish gradually in size dorsad. Terminal claws without the comb of spines but armed with a continuous series of very fine setz; on the convex side two small spines. Eye large, with many erystallines; macula nigra point-like. Length 1.20 mm., height 0.70 mm., height of head 0.25 mm., length of spine 0.11 mm. The male is smaller. Antennule somewhat curved; at the free end it bears, besides the sensory threads, a flagellum, which is some- what curved at the end and dark contoured at the base and is at least twice as long at the sensory setz. The lateral seta is situated some- what separated from the flagellum on the front (cephalic) margin of the antennule. There is the same cervical toothed process seen in the female. Abdominal processes absent. Length of male 0.78 mm.; height 0.42 mm. It would appear that Forbes D. dentifera is the American represen- tative of this species. It differs in having the cervical process much Ves *) ae ee a ee ~~) Or aa Ar. ee ee “=, Py we ea a af cs, 7 5 wag Dior hice ne oT Ae: Rare om : F ho" ho ove | f , : r Byes 202 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. further cephalad, i. e., over the base of the antenne rather immedi- ately in front of the heart. The beak in D. dentifera does not turm ventrad but caudad. * Daphnia dentifera Forbes. > PLATE LITT, Fie. 9: Forbes 793. Broadly oval, long beaked, species with a large eye, posterior spine high and with a prominent angle dorsally between heart and eye in the male and’ young female. Head broadly rounded, eye near ~ front margin. Fornices short, forming a prominent angle behind the base of the antenne. Lower margin of head concave, beak projecting. Eye large with numerous lenses, its diameter more than half the dis- tance from eye to beak. Pigment fleck immediately behind the eye and nearer it than the posterior margin of the head. Head crested, forming above the insertion of the antenne a rectangular process which in the young may bear two or three teeth. This process is re- duced to an obtuse angle in the adult female, disappearing in ephip- pial individuals entirely. Spine of shell long and slender, one third or one-fourth the length of the shell. Caudal ciaws smooth, anal spines 13. The two abdominal processes approximate. Length of female 1.8 mm. Male 1.0 mm. Very near if not identical with D. dentata Matile. This species differs from D. minnehaha chiefly in having smooth claws. Daphnia longiremis Sars. A species of moderate size and very hyaline. Head small and rounded, ventral margin somewhat concave, beak sharp, directed ventrad. Shell oval, spine short, straight, inclined dorsad. Antenne relatively long, extending to caudal margin of shell. Post abdomen similar to that of D. longispina. Macula absent. Eye small. Length 1.0mm. Apparently a pelagic form. We are not certain that ib represents an adult. * Daphnia magniceps Herrick. The peculiar form figured in the tenth annual report of this survey seems indubitably new and is distinguished by the peculiar shovel- shaped head, which is scarcely crested but is broadest beyond the mid- dle. The spine is long, the claws smooth, the abdominal processes united and the shell transparent. The eye is near the end of the rounded head and is large; the pigmeut fleck was apparently absent. Found with Daphnia minnehaha in a shallow swampy pool in autumn. ENTOMOSTRACA OF MINNESOTA. 203 Daphnia cucullata Sars. Kurz (vitrea). Very like the above, but the margin of head is not straight below, is, however, extremely variable and ends in a sharp angle. The eye lies nearly midway between the heart and the end of the head and near the lower margin. The two anterior processes of the abdomen are united for most of their length. Anal teeth five toseven. Claw ciliate. The flagellum of the male antenna is about as long as the ter- minal sete. D. apicata Kurz seems to be a large variety lacking the sharp spine: of the head. In the main it agrees quite well. Although the post- abdomen is broader than figured by Mueller, the number of teeth cor~ responds with Sars’ description. Length 0.95 to 1.11 mm. * Daphnia kalbergensis Schoedler. PLATES XXVII, Fias. 1-3; LIII Fias. 5-8. Schoedler (ccederstroemii, and berolinensis); Forbes (retrocurva). Rather delicate species of moderate size, inhabitants of clear and deep waters. Form oval, with a long nearly straight spine springing from near the middle of the posterior margin. Head very large and produced into an enormous helmet-like crest, which projects cepha- lad and may be somewhat or greatly curved dorsad. The size of the crest and its form are very variable even iu the same gathering. Eye small, with few lenses, distant from the ventral margin, macula want- ing. Antenne weak. Post-abdomen narrow, with from six to twelve anal teeth; claws weakly ciliated. Abdominal processes discrete. As above stated, the close association of forms in the same gather- ing ranging from D. vitrea to the extreme of D. retrocurva seems to: forbid their separation, even varietally. The case of D. vitrea is most open to doubt. The chief differences seem to lie in the small number (4) of anal teeth and the fusion of the two anal processes. A young specimen from Lake Minnetonka had but four large teeth and two inconspicuous ones and the anal processes were less distinct than in older individuals. All transitions could be-found. We agree with Hellich that this, at most, is a depauperate variety of D. kalbergensis. There seems to be absolutely no good reason for separating D. ceder- stremit or D. retrocurva, as the differences are largely a matter of uge and freedom to develop typically. P. E. Mueller gives the following measurements for D. kalbergensis: Head 0.9 to 1.0 mm., body 1.0 to 1.1 mm., spine 0.7 to 0.75 mm. 1 Oe Cen IO Te nly Oe ANE NE Ne eT 204 GEOL. AND NAT, HIST. SURVEY OF MINNESOTA. Kurz for his D. vitrea gives a length of 0.85 mm. plus 0.25 mm., the length of the spine. Judging from his figure, the head would not measure over 0.35 mm. Forbes says of his D. retrocurva that the head is two thirds as long as the body. Our specimens measured as follows: No. 1. 1.6 mm.; head somewhat more than half the body and almost exactly like D. vitrea in form. No. 2. Head 0.6 mm., body 0.9 mm., spine 0.5 mm.; about nine anal spines. Head in this case moderately curved upward. No. 3. Head 0.95 mm., body 0.95 or less, spine 0.5 mm.; or the head as long as, or, indeed, considerably longer than, the body and directed upward. The males have the crest much lower, the spine longer, and the form of antennules figured by P. E. Mueller. In the older females the beak is elevated above the antennules, as remarked by Forbes, but in smaller individuals there is very little difference between our speci- mens and Mueller’s figures. The claws of the post-abdomen have, besides the row of fine teeth mentioned by Mueller, a cluster of sharp teeth just at the base. Found, together with typical D. galeata and the rounded form, in a small deep lake or expansion of a creek not far from Medicine lake, Hennepin county, Minnesota. We have since found this species at a depth of 80 feet in Lake Min- netonka, and here also in association with D. hyalina. The range of variation is exceedingly great as indicated by the figures of Plate LITI. , Having given as fall a catalogue of the well known and accessible species as our circumstances now permit, it remains to notice the ex- istence of others which are either imperfectly described or the descrip- tions are out of reach. Daphnia similis Claus. PLATE XXXV, Fie. 5; LI, Fie. 7. The description of this species, which was bred in confinement from eggs brought in mud from Jerusalem, I am, unfortunately, unable to quote. Judging, however, from the figures which alone I now have access to, it belongs in the group of D. longispina, though in many particulars it resembles D. schefferi. The form is elongate, the spine short and springing from the upper margin. The antennule of the female is very large and flagellate, while that of the male is like that of D. sche fferi. The flagellum and hook of the first foot of male are rather small. ENTOMOSTRACA OF MINNESOTA. 205 W. Schmankewitsch described as new D. degenerata and D. rudis, from salt or brackish waters. These he regards as degenerate forms produced by the inferior aeration of dense waters. The author does not appear to recognize the modern distinctions of genera, so that, not having seen the work, even the generic position cannot be definitely stated. His investigations seem to show that the proximity of salt waters influence the form of the body, or, perhaps, that there is a con- stant interchange between the sub marine and fresh-water species. Daphnia brevicauda Chambers is an incorrectly figured and described Simocephalus. Daphnia bolivari Richard. Richard ’88. “*Caput a latera visum fere triangulare, latum, margine superiore recto; anteriore cum inferiore lineam usque ad apicem rostri eequaliter ac leviter arcuatam formante} rostro acuto brevi. Testa cetera margine dorsali subrecto inter caput et corpus leviter rinuato, margine ventrali aculeato parum arcuato. Spina teste longa aculeis multis ac validis ornata. In capite a latere viso linea circularis patet insignis distinctissime serie duplo aculeorum acutorum instructa, parte superiore modo levi. Ad apice dorsali et posteriore hugus linez sequitur linea alia eadem structura marginem supe- riorem teste usque ad apicem caudalis spine. Adest preterea linea alia in medis utriusque lateris testz, aculeis ornata. Antenne 1mi paris magn. 2di paris medi- ocres piliis brevibus sed distinctissimis ornate. Setz abdominales mediocres, ad ® apicem ciliis longis dense obsitz. Oculus mediocris crystallinis paucis perspicuis; macula ocularis rotunda, parva. Longit. fem. spina teste inclusa, 3.35 mm., spine, 0.8 mm.’’ This Spanish species is not sufficiently described to be allotted to its place among its congeners. The armature of the abdomen is abso- lutely essential. Daphnia carinata King. King 752-54. This form, though incompletely described, will be easily recognized when rediscovered. It belongs to the D. scehfferi group and is said to resemble D. similis Claus, being one of the largest of the genus. The head is armed with a crest but is depressed and uniformly rounded, The shell is oval with a long spine from the upper angle in the young female. Abdominal processes thick. Post-abdomen attenuated. De- tails of armature not given. Ephippium with four eggs. The eye ig somewhat distant from the margin. Daphnia gravis Schoedler seems to us but an extreme variation of the above as it was regarded by King. Daphnia kingti Schoedler is a very large species with the head greatly helmeted. The outline is nearly circular and rises above the level of the back. The shell is oval with an extremely long spine which is directed obliquely dorsad. 206 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. Daphina cephalata Schoedler is named from rude drawings by King, which, if they show anything, seem to prove that they rep- resent an abnormality, probably of D. kingii. The sac like disten- sion of the head is at the expense of the lower part of the head. Daphnia macrura Dana is identified by Schoedler with D. carinata King. Daphnia kisilkumensis Schoedler—D. vitrea Uljanin is apparently D. longiremis Sars. Daphnia newportii Baird, from India, is quite insufficiently de- scribed but belongs to the D. schefferi group. Schoedler mentions Daphnia brasiliensis Lubbock and Daphnia gran- aria Gay, from Chili. Haldemann’s Daphnia reticulata may be D. pulex and his Daphnia abrupta is Simocephalus, Daphnia lumholtzii Sars. PLATE LXVI, Fie. 6. This species from Australia is well characterized by acute depressed frontal spine and the flaring fornices which end in curved spines of *considerable length. The male and ephippial female lack the frontal Spine but preserve the long spine springing from the upper angle. Theantennules of the malesare very long and the flagellum two-jointed and about as long as the antennule. The claw of the first foot is greatly developed. The claws have no spines. The anal teeth are 12 or more. Abdominal processes discrete. FAMILY BOSMINIDE. Small cladocera of remarkable form, due to the great elongation and modification of the antennules, which are seated on a small con- ical beak-like projection of the ventral aspect of the head and form long, jointed, probosis-like appendages curved in various ways. The shell is laterally compressed and not sharply separated from the body. There is frequently a sharp spine at the caudo-ventral angles of the shell. The surface is reticulate, striate or smooth. Feet, six pairs. The first pair hooked in the male. The antenne have three and four-jointed rami and are very small. The post-abdomen is trun- cate and the claw is seated on a considerable prominence. Macula cerebri and cceca absent. As there is but the single genus [ Bosmina] we have included gen- eric characters. PF Me ae eR f Th ae * 4 ENTOMOSTRACA OF MINNESOTA. 207 These curious animals are often found at great depths in the larger lakes, though they may also occur in weedy localities. They are poor Swimmers and rarely caught in the net. *Bosmina cornuta Jurine. PLATE LXV, Fias. 3-5. Oval, almost spheroidal. Head high, concave below the eye, Beak long, its flagellum midway between the eye and end of beak. Eye large. Antennules curved like a hook composed of 10 or 11 seg- ments. Antenne as long as the end of the antennules, three-jointed ramus with five set, the four-jointed ramus with three setz. Shell high, greatest height in middle of the length. Back uniformly curved and forming an obtuse angle, with the straight caudal margin. Spines at the caudo-ventral angle short, turned dorsad. Shell hex- agonally reticulate. Post-abdomen short, truncate and excavated api- cally, with two anal spines. Claws finely pectinate. Length 0.4 to 0.54 mm. * Bosmina longirostris O. F. Miiller. PLATES XLV, Fie. 2; LXV, Fie. 2. General form oval, shell highest in the middle. Head high, beak short, flagellum arising from near the end of the beak, front pro- tuberant. Antenne longer than in 5. cornuta, three-jointed ramus with five, tour-jointed with four setw. Spines of shell short and straight. Post-abdomen short, truncate, unarmed. Claws on a pro- tuberance, pectinate. Length 0.31 to 0.35 mm. Bosmina longicornis Schoedler. Very similar to B. longirostris, but the front is not protuberant, the flagellum is midway between eye and end of beak. The spines of the shell are long, toothed ventrad and directed obliquely dorsad. Shell unmarked. The finely pectinate claws have at their base sev- eral large accessory spines. Length 0.36 mm. Bosmina brevicornis Hellich. A large species with depressed head having a uniformly rounded front. Shell higher than long and coarsely reticulate, spine short and curved. The beak is short and little curved, the flagellum being quite near the eye. The antennules have seven segments. The post- abdomen is large without anal spines and the claws are simply pectin_ ate. Length 0.55mm. MHellich says this differs from B. brevirostris P. E. Mueller, which has a protuberant front and long serrate Spine and the claws have seven accessory spines. 208 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. Bosmina bohemieca Hellich. Body large, slender. Head high, front uniformly rounded, flagel- lum nearer the end of beak than the eye. Beak short, rounded. Antennules long and arched, composed of 16 or 17 segments. The triangular spine above the sensory filaments large and acute. Shell as long as high, highest in the middle. Spine long, curved dorsad and toothed. Shell irregularly reticulate and longitudinally striate. Post-abdomen large, truncate and excavated. IJnferior angle ciliate. Claw protuberance long, unarmed. Claw with six spines at the base. Length 0.6 mm. Bosmina microps P. E. Mueller. Oblong, length much greater than height. Front not protuberant. Caudo-ventral angle of the shell without the spine, rectangular. An- tennules long, nearly straight, flagellum nearly midway between beak and eye. Length 0.5 mm. or less. The shell is reticulate and the antenne are very short. Bosmina maritima P. E. Mueiler. Oblong, longer than high, front moderately protuberant. Shell strongly arched above; spine long, directed obliquely ventrad. An- tennules slender, gently curved; flagellum near the beak. Shell smooth. Length 0.5 mm. Bosmina brevirostris P. E. Mueller. Oblong, length greater than height, front greatly protuberant. Shell arched above, strongly spined. Antennules moderate, straight- ish but inclined caudad. Flagellum near end of beak, sensory set remote. Length 0.6 to 0.7 mm. Color reddish. Bosmina diaphana P. E. Mueller. Gibbous, length greater than height, front not protuberant. A slight sinuosity in the dorsal outline over antennz. Shell very strongly arched without the spine, smooth. Antennules very long, curved, converging at the ends. Flagellum near the end of the beak. Length 0.6 to 0.7 mm. Bosmina lilljeborgii Sars. PLATE XLV, Fia. 3. Very gibbous dorsally, length and breadth nearly equal, front not protuberant. Dorsal outline sinuous over the antenne. Spine ab- sent. Antennules longer than the body, straight or slightly curved, divergent. Flagellum near end of beak. Length 0.6 to 0.75 mm. a Ph es a AM he ie SU eye ee, Ty, SS ; = ss ENTOMOSTRACA OF MINNESOTA. 209 Bosmina ecurvirostris Fischer. Body rounded, length little greater than height, front somewhat protuberant, dorsal margin strongly arched, antennules short and strongly curved. Flagellum midway between eye and end of beak. Seven to eight sete upon the cephalic aspect of antenne. Length 0.39 to 0.4 mm. * Bosmina striata Herrick. PLATE LXV, Fie. 1. Herrick ’82. This form is very imperfectly known, but resembles B. bohemica and may be identical, but that is a much larger form. Oblong, slen- der, greatest height cephalad of middle, front strongly arched. Hye large. Flagellum near the beak. Antennules very long, curved. Shell irregularly marked with anastomosing longitudinal lines pro- ducing a deformed reticulation. Spine large, curved, but not long. Ventral margin sinuous, ciliated cepbalad. Length 0.25 mm. * Bosmina atlantaensis Turner. This is not adequately described. It, however, affords proof of the existence of a fourth typeof Bosmina in America. JB. longirostris, B. cornuta and B. striata all have the shell marked and peculiarities of structure otherwise. The southern form has a smooth shell, long antennules, depressed spine, sinus between head and body, and fla- gellum nearer to the eye than to the sensory sete. The post-abdomen is broad and the claws toothed. The whole genus requires revision. Other species which cannot now be placed are the following: . gibbera and B. rotunda Schoedler. . levis Leydig, probably the young of longirostris, . londensis Norman and Brady. . obtusirostris Sars, probably is B. brevirostris. . lacustris and B. nitida Sars. . coregoni Norman and Brady, is B. lilljeborgit. . macrorhyncha, a species from the Nile. Bo bbood FAMILY LYNCODAPHNID Sars ’61; Herrick ’81. This is a rather small family with several genera of minute animals which are abundant only insummer. Many, and indeed most, of the species are among the rarer of fresh water crustaceans of this group, and a few are among the rarities which only now and then reward the 210 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. collector. This family undoubtedly is the link connecting the Daph- nide with the Lynceide, relationships to which are expressed by Macrothrix, on the one hand, and Lyncodaphaia on the other. The rank of this group as a family must be, of course, a matter largely of opinion. Sars was the first to adopt this view, sustained by certain curious transition forms leading toward Lynceidw. Later writers seem never to have found these genera and the group was again included with the Daphnide. The writer (82), npon the discov- ery of the Lyncodaphnia was forced to regard this group as of equiva- lent grade with the above mentioned families and again proposed the family name Lyncodaphnide. The genus Ilyocryptus is a little one side the normal course of the family and seems related to the lynceid genus Leydigia. The waters of the northern United States are very rich in members of this family. The aberrant family Bosminide finds its only connection with other Cladocera through this group by means of the remarkable Macro- thrix (2) pauper; and here it is only vaguely hinted at in the elongated antennules and angled lower margin of shell, as well as the presence of certain bodies near the base of the antennules. It has been affirmed that none of the Lyncodaphnide have an ephippium, i. e., the saddle- shaped thickening of the shell walls to include and protect the winter eggs; but I have discovered it in the case of Macrothrix tenuicornis Kurz and presume it may occur exceptionally in others. Kurz says that Ilyocryptus has no moult proper, but this probably refers only to the European J. sordidus. The American species differs from the generic description given by Kurz, and may be different in this respect also. In this family the regularity in the disposition of the sete on the antenne is broken and the fringing of these hairs serves the purpose of specific distinction. The antennules are always long and frequently differ considerably in the sexes. The pigment fleck is always present (Kurz is in error in denying its existence in Lathonura). In many forms there is no free posterior margin of the valves, while the lower is generally thickly beset with movable spines. The Lyncodaphnide will be distinguished from Ceriodaphnia, which they resemble, by their motion, which is a succession of quick bounds, while the broader Ceriodaphnie hobble along as though heavily weighted by the enor- mous mass of eggs with which they are generally laden. The abdomen is usually short and the anus is behind the terminal claws, but in Ily- ocryptus the claws are long and spined at the base. In the American I. spinifer the anal opening is elevated to a point nearly underneath the stylets, and there is a rudimentary anal czcum as in Lynceids. ; ENTOMOSTRAOA OF MINNESOTA. 2 ik Ame tht ng as al ite ES a car, TDA SL! Pcl iy’ 211 The males have the opening of the vasa deferentia in front of the claws, which may be absent; the antennules are also modified, being longer and curved. Jn Lathonura the abdomen is elongated posteriorly till it begins to suggest a transition to Polyphemus. The known genera and their distribution is as indicated below. Half of the known species are found in America, one-fourth being peculiar to it. i a | a Gusena. Number of| Eoropean, | 4,400, | Onlin) Total Species. 4 NIRCPOUNTLR cncc uaunete desis csvesscteneant 4 3 2 1 3 SUM OTULTaasenceels oa ceseece cites oo ubiaw nes 1 1 MAY A iteredaceeeites 1 | MO PAMOUNTER ce ciseosee en sveodoess Sees 1 RTE Wi Ree set ven seeeall ot aac cone recalerece ame eeeem : IME LOCELAS i aatce asst cdadenvce cal sense il Glee Weep a asic cle oan ell eaite asl bake esateeeeeneee § IA CAMUNOLEDETIS:. vseesseuel seeaenesees« 1 Re) Se) wate, Lag cella senavaee eee lceoe meced metee Ouiny Oma sitar «Rees siiate scewsenseacines s¢au'e 1 i dra ene ceeerstige 1 iy WEG Map uitde:e sc). tear ercscwene plete eV ale Dea har Wel : » ae Fah be ae Tee dh 216 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. *Lathonura rectirostris O. F. Miiller. PLATE LVII. Koch ’35-’41 (Pasithea rectirostris); Zaddach 744 (Daphnia brachyura); Lievin 748 (Daphnia bracbyura); Fischer ’52 (Daphnia mystacina); Liljeborg ’53; Leydig 760 (Pasithea rectirostris); Norman and Brady ’67; P. E. Mueller ’68; Schoedler ’58 (spinosa); Birge ’78; Gruber and Weismann ’80 (Pasithea rectirostris); Herrick ’82. The only species of the genus is distributed probably over the entire northern temperate zone. It has been found in America at Cambridge, Mass., and in the vicinity of Minneapolis, at both of which places it is very rare. The form is a rather quadrangular oval, the head being strongly arched to the beak which is much farther posterior than in Macrothria, in this respect resembling the Daphnide; the eye occupies the center of the lower part of the head margin, and is of moderate size; the pig- ment fleck is near the base of the antennules and well removed from the eye; the antenne are straight and long, with a sensory bristle near the base in front and two bristles athird fromthe end; the second antenne are furnished with a powerful basal joint, while each of the main subdivisions of the rami has its bristle, which are nearly equal; two of the terminal sets are toothed for the basal half and pectinate distally, but the others are feathered throughout; the four-jointed ramus has a spine on the second joint and a longer one at the end, and all the joints of both rami are ornamented with triple series of spines; the maxille are three spined at the end and are in almost constant motion; the first pairs of feet have curious comb-like bunches on some of the sete; the abdomen is very short and terminates in inconspicuous teeth, the posterior part of the abdomen being ornamented with teeth flattened longitudinally so as to look like spines from the side; the last foot is simple but bears a large appendage; the posterior third of the shell is fringed by extremely minute spines, but anteriorly by lanceolate stiff spines flattened longitudinally like the spines of the abdomen; the caudal sete are seated on a high prominence of the ab- domen, and are fringed along their whole length, not merely at the end. The female is 1.0 mm. long, the male 0.5 to 0.6 mm., in which sex the antennules have more numerous lateral bristles, the first foot has a claw and the back is less elevated. The semen bodies are irreg- ularly round with small nuclei. GENUS STREBLOCERUS Sars. In form like Macrothrix laticornis, head terminating in a long ros- trum bearing the long, twisted antennules. Antennules very large, curved backward and outward. Head not separated by a distinct ENTOMOSTRACA OF MINNESOTA. 217 depression from the body, very high, slightly arched above, abruptly curved below with spines upon the margins. The antenne& are large; four-jointed ramus much the longer, with four sete. Labrum with a _large process. Post-abdomen much as in Macrothrix laticornis, serrated or notched behind. Eye near the beak; pigment fleck small, situated below the eye at the base of the antennules. The shell is hexagonally reticulate, arched above and angled below; ventral margin armed with rigid spines. . Claws ciliate. Length 0.34 to 0.4 mm. Our Macrothrix pauper seems a near approach to this genus; both have a strong spine or claw on the first foot which projects beyond the shell, but there are many differences. M. pauper is 1.0 mm. long. S. serricaudatus Sars (Plate LX VI, Fig. 1) is the only species. GENUS DREPANOTHRIX Sars. The head separated from the valves by a depression; fornices mod- erate; rostrum rather acute, distant from the anterior edge of the valves. The form is subrotund; reticulate, with the margins of shell fringed below by long movable spines; pigment fleck present; swim- ming antenne with three ciliated sete on the four-jointed ramus, the three-jointed ramus with its basal joint armed with an unjointed, Strong, spinous seta and four ciliated sete on the remaining joints. The post-abdomen is broad. Intestine coiled. The male has longer antenne and a hook on the first foot. Drepanothrix dentata Euren. PLATES XLVI, Fia. 9; LIV, Fie. 4; LVI, Fia. 14. Acantholcbcris dentata—Euren. Drepanothrix setigera—Sars. Drepanothrix hamata—Sars. * Drepanothrix hamata Norman and Brady. This animal is only 0.5 mm. in length. The antennules are later- ally curved in the middle and ornamented with notches on the mar- gins; the pigment fleck is quadrate and rather large; the post-abdomen is truncate at the end, convex behind and ornamented with a series of small spines. Shell margins with long spines. Birge reports this species from Lake Wingra near Madison, Wis- consin. It seems to be repelled by light and is a bottom-loving form. Though it swims fairly well, the stiff setz are chiefly used as pushing poles. The species has been taken in Denmark, Scandinavia, Eng- land and France as well as America. 218 GENUS ACANTHOLEBERIS Lilljeborg. Body more or less quadrangular, head triangular, acute cephalad, bearing the antennules at the front. Fornix slightly developed. Head scarcely separated by a depression from the body. Antennules elongate, expanded apically. The three-jointed branch of the antenne has five sets, the four-jointed ramus has three, all being apical. The seta of the basal joint of the three jointed ramus is elongate. Labrum with an acute process. Feet six pairs. Intestine with a loop. Post- abdomen broad, armed with a Series of spines. Margin of the shell with long spines below. Ancantholeberis curvirostris O. F. Miller. PLATE XLYI, Frias. 1-4. O. F. Miiller 1785 (Daphnia curvirostris); Schoedler ’46 (Acanthocereus rigidus); Lievin 48 (Acanthocercus rigidus); Lilljeborg ’53, and ’58 (1igida); Leydig ’60 (rigidus); Norman ’63; Norman and Brady ’67; P. E. Mueller ’68; Lund ’70-’71; Hellich ’77. This rare species has not yet been found in America but may be confidently expected. The aspect is macrothroid, the whole ventral margin being long ciliate, while from near the posterior angle arise a number of greatly elongated setz. The caudal margins are armed with short spines. The macula is present but rather small. The an- tennules are elongate, expanded toward the tip, somewhat curved and armed apically with about eight unequal lanceolate processes and smaller spinules. The post-abdomen is broad, rounded distally. The claws have two small basal teeth and a series of small sete. The pos- terior margin is armed with a series of small teeth. Length less than 1.5 mm. GENUS OFRYOXUS Sars. Lyncodaphnia—Herrick. Body elongated, somewhat rectangular as seen from the side, great- est width and height of shell a little posterior to the heart; head sepa- rated by a depression from the body, truncate below; antennz and antennules much as in Macrothrix; four jointed ramus of antenne with no lateral setze; eye small, pigment fleck present; intestine twice con- voluted, expanded posteriorly, with anterior but no posterior cxca, opening near the ‘‘heel’’ of the post-abdomen; post-abdomen large, triangular; terminal claws long, rather straight, with two accessory spines at the base. . Ofryoxus is, aS Was Suggested, a curious transition form linking the Daphnide with the Lynceide. ‘ a M oa ones ans ee ate ENTOMOSTRACA OF MINNESOTA. 219 O. gracilis not only has the dise-like last foot colored but the swim- ming antenne are banded with purple as in Simocephalus rostratus Herrick and S. americanus Birge. The intestine has anterior cca, which is not the case in Lynceids, nor, indeed, in other Lyncodaphnide. The four-jointed ramus of the antennze approaches Lynceide in the absence of a lateral seta, but the other ramus is as in Macrothrix. The convolution of the intestine, the form of the post-abdomen and the situation of the anus are all of a strictly Iynceid type; moreover, the flattened appendage of the last foot is like that of Hurycercus. Even in the form of the shell there is a combination of characters; the anterior part of the shell has the form peculiar to Lyncodaphnide; but posteriorly it again expands and becomes truncate behind; the form in the adult is not unlike that of some Lynceide, but the young has a long spine posteriorly exactly like the spine of Daphnia. The latter fact is very instructive, for it indicates that the theory proposed (American Naturalist, 1882, p. 815) to explain the origin of this ap- pendage is probably the correct one. Professor Leuckart suggested that this spine was a balancing rod intended to keep the proper equi- poise over the center of gravity; but it is difficult to see why these long-bodied forms, in which the greater part of the weight lies “‘abaft’’ of the pivotal point—the base of the antenne—should be thus provided while the shorter forms are not. We conceive that it is an apparatus for effecting the moult of the inner lining of the brood cavity of long-bodied and tender-shelled animals such as Daphnia and the present genus. The great development of the head in the crested Daphnide may undoubtedly be explained upon Professor Leuckart’s theory. * Ofryoxus gracilis Sars. PLATES XLII, Fiaes. 12-15; LVIII, Fras. 1-3; LIX, Fia. 2. Herrick ’82 (Lyncodaphnia macrothroides). Sub-rectangular, greatly elongated, truncate behind, with a slight spine above; head and eye small, fornix moderate, beak truncate; an- tennules rather long, slightly curved, tapering a little toward the end, whence spring three lanceolate spines and several sensory filaments, five stout spines behind, above the middle, and several more slender ones; Swimming antennée very long, terminal sete smooth to the joint; labrum as in Daphnia; mandible attached behind a salient angle of the front margin of the shell; no abdominal processes; post-abdomen broad above, triangular; terminal claws pectinate, furnished with one very large toothed accessory spine and a smaller one; the first foot has a hook; the last foot consists of a large oval plate which bears poste- > PE eR TIE Ie oF is a ey gt RRP oe ce tp) ¥ 220 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. riorly the ordinary branchial coil, here shaped like a thumb and fore- finger. The young is of a different shape and bears a long spine, The male is known from figures recently published by Birge (’91). GENUS ILYOCRYPTUS. Form compact, short; head short, triangular, with large fornices forming a roof over the head; the posterior margin of shell nearly as long as the inferior; lower angle a broad curve; antennules two-jointed, basal joint very short, second joint straight, rather long; sete termi- nal, but one seta near the base; the four-jointed ramus of the antenna with but three (terminal) set; six pairs of feet, last pair rudimentary; tail large, as in Lyncodaphnia, anus elevated; intestine straight, with- out ceca, but an expansion near the rectum sometimes simulates one; the margin of the shell is bordered with long spines, which may be branched or simply pectinate. There is often, perhaps generally, a failure to entirely remove the moulted shell; when this occurs the newly-formed shell from each moult remains under the older ones till the animal seems to be wearing six or more overcoats, and the spaces so formed become filled with alge and filth till the animal is no longer able toswim. P. E. Mueller and Kurz, who seem to have seen only I. sordidus, agree that Ilyocryptus cannot swim, but poles along in the mud on the bottom by means of antennz and abdomen; our J. spinifer, on the other hand, swims freely till loaded up with old clothes and filth. This genus is also closely allied with the Lynceide. * Tlyocryptus sordidus Lievin. PLATES LV, Fias. 6, 10, 11; LVI, Frias. 15-17. Acanthocercus sordidus—Lievin, Leydig. Body higher than long; head small, terminating anteriorly in almost a right angle; posterior part of the shell margins covered with branching, thorny spines; antennules cylindrical; antenne short; four- jointed rami with no lateral sete; post abdomen large, broad; terminal claws with two spines at the base; anus in the middle of the posterior margin, which is very heavily armed with spines; a hairy abdominal process is present, according to Kurz. There are no anterior ceca (my statement that P. E. Mueller de- scribed such czeca was an error; see Notes on Cladoreca of Minnesota, p. 246). Length 0.78 mm. The tabulated comparison beyond makes a full description unnecessary. Birge reports this species from Wis- consin and it has been encountered in Minnesota. ENTOMOSTRACA OF MINNESOTA. 22% * Tlyocryptus spinifer Herrick. PLatsEs LV, Fias. 1-4; LVI, Fias. 18-19, 21. Herrick ’82, ’84, and ’87; Turner ’93. The description given in my Final Report, ete., is very brief, and no - comparisons were there instituted with the J. agilis of Kurz, which is its nearest ally in Europe. The paper by Kurz referred to gives de- tailed descriptions of the three European species, accompanied by ele- gant plates. We are able, therefore, to draw up the following dis- tinctive diagnosis of the species, hoping thereby and by means of the figures to show the relations of the four species at present known. It is almost certain that we have more than one species in America, and the careful description of the known form may make the detection of others easier. The size varies greatly; a full grown female with eggs in the brood cavity is nearly 0.90 mm. long and 0.70 high, while a smaller female measures 0.65 mm. long by 0.44 high. The form of the shell is nearest like that of J. acutifrons, the height being less than in J. sordidus, and the angle between the ventral and posterior margins less than in J. agilis. The entire length of the post abdomen in the large female is 0.56 mm. measured to the base of the caudal stylets, of which length 0.165 mm. pertains to the claws. The width of the post-abdomen is but 0.14 mm. Thus it is evident that the proportions of the post- abdomen differ greatly from any of the other species, it being very | long and narrow. The terminal claws are exactly as in J. agilis, hav- ing two Small basal spines and a few sharp serrations near the apex, anteriorly. Near the base of the claw is a cluster of small spines of two sizes, then begins a series of about 16 lateral teeth averaging 0.02 mm. in length and extending to the sides of the anus. Above this point the contour of the margin is convex and is ornamented with nine spines twice as long as the preceding. Then follow the promi- nences which bear the long and simple caudal sete. Besides the above mentioned spines there are four spines on either side upon the lower posterior angle of the post-abdomen which are four times as long as those of the previously mentioned continuous series (i. e., 0.08 mm.). Above, the abdomen is hirsute or thorny as in J. agilis, and the process for closing the brood sac is similar. It will be seen that the post-abdomen differs in armature as much as in form from other species. From J. sordidus it differs in the following points: The claws are not pectinate behind but are serrate in front, the anal open- ing is higher and the details of the spines vary; from J. acutifrons it differs in that the claws are not pectinate, neither is there a spine in front of the claws, and the anus is not terminal; from J. agilis it differs in that the shape is different, there are fewer enlarged spines, and the shape of the nine spines above the anus is different. The head is con- vex, resembling J. sordidus most nearly, but the antennules are much longer and more slender than in any other known species. They are 0.17 mm. long and about 0.016 mm. wide, while the longest seta is 0.084 mm. long. The antenne are almost exactly as in J. sordidus. — The labrum has the usual shape, as have the jaws and other append- ages. The margins of the shell are ornamented with spines simply pectinate or barbed as in J. agilis. In I. sordidus these spines are variously branched, and in that form alone of the European species, according to Kurz, is there a failure to perfect the moult; in our spe- cies, which has simply pectinate sete, the oid coverings are all but uniformly retained. The spines of the Jower posterior margin are from 0.16 mm. to 0.20 mm, long. Such are some of the chief peculiarities of the species, but, to make the relation between the four species of this little known genus even clearer, if possible, the following comparative table is appended. Mhe:shellmoulhed periodically... scsav-ves.ncctaacaceseeshascssederassencedae wee x rite : The shell not moulted Dwi retained: 2) ss... cssacesceesaneienccanedeceeneesareccns { 7 anne Antennules not more than eight times as long as broad.............2ee000 I. agilis. I acutifrons. Antennules more than eight times as long as broad............ceeeceeeeeeee I. spinifer. I. sordidus. | I. sordidus. Claw of post-abdomen: pectinate ro... 0.0.02 ncccssceses eae en clevedslesvaliadsesretnes T. acutifrons. ; I, agilis. Claw of post-abdomen not pectinate.........ccccerscsccscssenetascsccescosserees L. spinifer. ATSELONS GPINEMNHTONG Ol ClAWi.c sts ncactees.seces s+sesteoadeeuon Aeeee leases eas I. acutifrons. I. sordidus. Fine bristles or none in front Of Claw. .........0:sssessscesssocncesnsenniacecevess | I. agils. : I. spinifer. Amns-opening near Ghel@laws:.:.-.n-scsssecss-nccnuecedaes wee os-aceheeeast-aatieies I. acutifrons. I. sordidus. Anus about midway of the posterior border............... suadean easeeees sence I. agilis. I, spinifer. Marginal spines:of shell much branchedin ci. nsec ces csesenessncuncscrcwssess I. sordidus. I, agilis. Marginal spines nowhere much branched............... cae Seance cuetratee I. acutifrons. I, spinifer. Elongated anal spines on either side, four or five, very long.............. I. spinifer. I. agilis. Elongated anal spines MOTe NUMETOUS ..........0..0.ecerccvevere ccs ncscecses {2 acutifrons. I. sordidus. Upper (one to three) spines of the supra-anal series modified erent aculifrons. CMIAT OCH ie. eccece«cpekeapedesesscisns sconecses ce tleesccannae Mlcals taaeie aa tater taree «>. LL. agilis. I, sordidus. Upper’spines like the Others or. voc .cccc0.. veeccncns ctocncsonecseccavertscsesnviensese L. spinifer oe ee ENTOMOSTRACA OF MINNESOTA. Doe The above is extracted verbatim from the Alabama Crustacea, which Professor Birge should have consulted before saying ‘‘none of the specific characters are mentioned or figured”’ (Birge ’91). Professor Birge is inclined to identify our species with J. longirenvis Sars, from Australia. But ifthe Madison specimens have antennary setze nearly equaling the total length of the animal, they differ from all individuals of J. spinifer yet seen. The armature of the post-ab- domen is also different, for there are but four elongated claws at the inferior angle and a series of about 14 anal spines and six longer supra- anal teeth. We infer from Birge’s figure that the antenne are dif- ferent. It would be well that the Madison form should be more eare- fully described and figured and compared with other American species. Length 0.60 mm., height 0.46 mm., base of antenna 0.19 mm., four- jointed ramus 0.13 mm., post-abdomen 0.19 mm., claw 0.125 mm., long post anal spines 0.06 mm., antennule 0.10 mm. Ilyocryptus acutifrons Sars. PLATE LV, FIa. 7. This species is only mentioned in the appendix to the paper of Sars on the Cladocera from the vicinity of Christiania. The following is a condensation of the description. Head large, acute in front. Shell truncate behind, with shorter setze behind than below. Antennules shorter and thicker than in I. sordidus. Antenne long and robust. Abdomen with a short, obtuse process. Post-abdomen shorter than in J. sordidus, posterior margin continuous, anus terminal; caudal claws straight, very long, with two minute basal spines and a cluster of teeth in front. Pigment fleck almost touching the eye. Length less than in J. sordidus, 0.6 mm. In this species the moult is perfect. (See table above. ) *Tlyocryptus longiremis Sars. PLATE LY, Fia. 5. Sars ’88; Birge ’91. Professor Birge finds this species abundant near Madison. The original description is not now accessible. It appears, however, that the form of the post-abdomen is very similar to I. spinifer, while its armature is quite different. The sete of the antenne are very long, nearly equaling the length of the body. There are five to seven super-anal teeth, largest in the middle, an outer row of about eight long post-anal spines and an inner row of 11 to 12 post-anal denticles, besides several very small teeth near the terminal claw. | There are three or four denticles on each side of the anus. The moult is incom- plete as in J. spinifer. 224 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. FAMILY LYNCEIDE. This family, which is numerically the largest among the Cladocera, is, in the main, well limited, though there are transitions toward the Lyncodaphnide, which are quite direct. The genera Lyncodaphnia, Ofryoxus and Ilyocryptus lead toward the Lynceide unmistakably. Most of the members of this family are small, comparatively few ex- ceeding one millimeter in Jength. The head is covered with an arched shield, which frequently passes with no indentation into the shell of the body. This head covering generally extends forward and down- ward to form more or less of a Sharp angle in front, while in several genera it is simply rounded in front. It, in either case, arches over the more fleshy lower side of the head from which hang the two short antennules and the labrum, while the strong two-branched antennze spring from well up under its posterior expansion. The rounded sides of this shield, which protect the insertion of the antenne, are called the fornices. Above the insertion of antennules is a dark fleck lying near or on the lower angle of the brain; this is the larval or nauplius eye, which is the first to appear in all these small crustacea. This macula nigra is not infrequently as large as the eye itself,* or even larger, and in one genus it is the only visual organ. The anteunules are small and bear on the end several sensory filaments as well as a lateral flagellum. The antennules of the male differ very little from those of the female. The labrum is furnished with a process, which is triangular or semicircular and is usually larger than the terminal portion. The mandibles are as in Daphnide but usually shorter. Maxille are often conspicuous, but the first pair of feet serve, by a slight alteration at the base, the same purpose. There is rarely an indication of the sixth pair of feet, and the antenne have both rami three-jointed. The terminal part of the body, or post-abdomen, is usally enlarged, and the anal opening is near its base; the armature is usually considerable. The form of the post-abdomen is one of the best criteria for distinguishing genera and species—a process often attended with much difficulty. The shell is of various forms, frequently beautifully sculptured. The number of eggs produced at one time is limited, and the winter eggs are very often laid in the brood-cavity with no preparation of the shell previous to it; in other words, the ephippium may be absent. On the other hand, sometimes the shell is considerably modified, and generally there is a deposit of dark pigment in the upper part of the shell. The males are very rare and until recently few were known. The diligence of Kurz has added a great many, and we now havea * The name “ Lynceus” is derived from that of the son of Aphareus who was famous for the sharp- nameness of his vision. ENTOMOSTRACA OF MINNESOTA. 225 fair idea of the sexual variations. These consist usually in a narrower body and shorter beak, in a strong hook of chitin on the first foot and certain modifications of the post-abdomen. The hook mentioned is simply an enlargement of one of the terminal bristles of the foot, and serves to fasten the animal to the shell of the female. In one Ameri- can species of Plewroxus we find an approach to this structure in the female—an interesting example of inheritance of sexual peculiarities across the sexes. The alterations in the form of the post-abdomen consist in a narrowing or excavation of that organ to permit its intro- duction into the brood-cavity, and in some forms (Chydorus) this change can only be understood by observing the form of the shell of the female about to produce winter eggs. In general, as in other Cladocera, males are found only at the period when the females are sexually perfect. The ordinary method of reproduction is by virgin- bearing or parthenogenesis. In some cases it would seem, from Weis- mann’s observations, that the sexual method occurs only incidentally. The orifice of the male organs is between, or anterior to, the terminal claws of the post-abdomen (Hurycercus alone excepted). The males are usually but not always smaller. Plate LXI gives views of typical Iynceide. Fig. 1 is particularly instructive, for in it the details which can be usually made out in the living object are represented. The following points may be especially noticed. The large size of the pigment fleck, the large antennules (A?), the keel of the labrum (Lb.), the peculiar modification of the first pair of feet to assist the maxille (not shown) which are exceedingly small, the largely developed anal gland (A. g.), the form and muscular mechanism of the abdomen, which, however, is better illustrated by Fig. 10 of the same plate. Fig. 1 contains an embryo seen from the side with the partially devel- opedlimb. Fig. 3shows the appearance of a different embryo from be- lowand in anearlierstage. Fig. 2 illustratesthe relation of the brain to the eye and the very small optic ganglion. Fig. 9 of Plate LXIII gives details of the feet in another species, and the modifications seen in the male of the same species are sufficiently shown in Fig. 1 of the same plate, which also well illustrates the various sculpture of the shell displayed by this group. Figs. 4 and 9 of Plate LXIV show curious modifications of the post-abdomen of the male, and Fig. 7 ex- hibits the structural peculiarity of sexually perfect females which is correlated with it, or, perhaps, we may say, occasions it. SUB-FAMILY EURYCERCINE. A single species constitutes the sub-family, and it will be necessary to point out only those points which are distinctive. The ELurycercine differ from the true Lynceide and approach the Lyncodaphnide in having the digestive tract not coiled, with two cec, 4 226 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. in front and the anus at the end of the post-abdomen. Many eggs are produced at once. The male opening is at the base of the abdomen, as in Sididw. The general habitus is, however, lynceid. The males appear in autumn or when, by the gradual drying up of the water or other causes, the continued existence of the animals is threatened. GENUS EURYCERCUS Baird. Characters of the sub-family. Eurycercus lamellatus O. F. Miiller. PLATES XLVI, Fies.. 7, 8; LI, Fie. 6; Lae Fies. 5, 6; LXII, Fie. 19. Lynceus lamellatus — Mueller, Edwards, Koch, Zaddach, Lievin, Leydig, Zenker. Eurycercus laticaudatus — Fischer, Schoedler. A gigantie Zynceid, reaching the dimension of 3.0 mm. The figure of the male given will sufficiently illustrate the general form. The abdomen is broad and armed behind with a dense row of saw teeth. The eye is larger than the rather small pigment fleck, and the intes- tine is bent upon itself but not coiled. The last foot is found in few other Iynceide. Acroperus has the same, and Pleuroxus unidens also has a rudimentary sixth foot. SUB-FAMILY LYNCEINE. Intestine coiled; anus near the end of the post-abdomen; opening of vas deferens nearly terminal. There are no anterior ceca but usually a single anal diverticle of the intestine. Rarely or never more than two embryos produced at once. KEY TO THE SUB-FAMILY LYNCEINE. I. Head or dorsal line keeled or ridged; abdomen long; shell marked with diagonal striz. Camptocercus, 227, 228; Acroperus, 227; Alonopsis, 231 II. Usually no keel above, or, if keeled, the post-abdomen is not long. The majority are highly arched dorsally, and have comparatively short post- abdomen and pointed beak. The antennz are usually feeble and the motion slow. | A. Post-abdomen nearly round in outline, armed with very long, stout spines, terminal claw with one minute basal spine or none; greatest height of shell about equal to the posterior margin. . Leydigia, 233 B. Post-abdomen more or less triangular, armed with bristles; greatest height of sheil moderately exceeding that of the posterior margin; shell marked with hexagonal meshes. ENTOMOSTRACA OF MINNESOTA. DG a. Head nearly horizontal, blunt; post-abdomen prominent in the anal region. . . . . . Graptoleberis, 235 b. Head depressed, acute; Port: ahdaien excised near the anus, Dunhevidia (—Crepidocercus), 236 C. Post-abdomen more or less quadrangular, armed with one or two rows of small teeth on either side behind; terminal claws with one or two basal spines; height of posterior shell margin usually less than the greatest height of the shell. . . . . Lynceus, 237 D. Pcst-abdomen terete; greatest height of shell little ies than that of posterior shell margin; terminal claws very minute. ‘ Phrixura. E. Greatest height of shell more than double that of the posterior margin. a. Eye and first foot normal. . . . . . . . Chydorus, 260 b. First foot with a claw which extends enna shell. Anchistropus, 264 c. Eye absent, only the pigment spot used for vision. . Monospilus, 264 (Not noticed in the key. . Alona, 238; Alonella, 249; Pleuroxus, 243 ) SERIES A.—This section is proposed for the old genera Camptocercus, Acroperus, and Alonopsis, which seem to form a natural group though passing into Alona. GENUS CAMPTOCERCUS (> Camptocercus Baird). - This easily recognizable genus contains two groups, each with sev- eral nominal species, which are distinguished mainly by the width of the post-abdomen. In both the shell is elongated, more or less quad- rangular, longitudinally striate, armed behind with one to four minute teeth. The head and back are keeled and the former strongly arched. The antennules rarely extend beyond the beak and are commonly curved laterally. The eye is proportionately small. The post-abdo- men is long and furnished with a lateral row of scales. The terminal claws have a single basal spine and are serrate. There is an ephip- pium, and the male opening is in front of the terminal claws. SUB-GENUS ACROPERUS Baird. Post abdomen broad, margins parallel; anal teeth very minute, lateral scales large and usurping their place. Antenne with eight setae (2°). Three species are described, one of which is very abund- ant in Minnesota. * Acroperus leucocephalus Koch. PLATES LXI, Fie. 5; LXII, Fie. 9. Lynceus leucocephaltus—Koch, Fischer. Acroperus harpe—Baird. Acroperus sp.—Herrick. Acroperus striatus—Jurine, M. Edwards, Lievin, Lilljeborg, Leydig, etc., seems to belong here, but I am able to add nothing to the elucidation of the puzzle. Body rounded above, angled behind; head moderately arched and carinated. Lower margin of the shell pectinate, terminating in two 15 228 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. 5 ;eeth. The antenne are long and when reflexed the sete reach nearly +o the posterior margin of the shell. The posterior angle is not always as prominent as shown in Fig. 5, Plate LXI. * Acroperus angustatus Sars. PLATE LXII, Fie. 10. This species is distinguished from the former by the head, which is higher and very strongly arched. The dorsal contour is nearly straight. The antenne are shorter. The form of the post-abdomen of the male is iess different from that of the female than in the above. The length of both species is about 0.7 mm. The American form figured in Fig. 5 of Plate LXI differs from both the above slightly. The head is carinated and incurved almost as in O. angustatus; the antenne fall a little short of reaching the pos- terior margin of the too low and oblong shell; there is an obvious de- pression between the head and the body. However, in the main there is close agreement with C. leucocephalus, to which it has been previously referred. There is always a rudiment of an additional pair of feet. A. cavirostris P. E. Mueller, is not known in the female sex. The male has a twisted caudal claw. It is probably founded on an ab- normal individual. Acroperus alonoides Hudendorff. This species is only known to me from incidental references in Matile. The post-abdomen is said to be broader than in either of the above. The claws have only one basal spine. The crest is low and the macula is nearer the end of the beak than the eye. (Acroperus transylvanicus Daday.) ‘Carina capitis rotundata; testa corporis dorsali leniter rotundato; postice angulo indistincto; margine ventrali fere recto angulum inermem formanti, cauda apice rotundata incisa; unguibus caudalibus magnis, fere rectis. Longit 0.85 to 0.9 mm.”’ The figures do not greatly fill out this hopeless description. The form is short and so is the abdomen, but the armature of the latter has nothing distinctive. SUB-GENUS CAMPTOCERCUS Baird. Although the general form is similar to the last section, the body is usually longer; the post-abdomen narrows toward the end; the anal teeth exceed the lateral row; the antennze have usually but seven setze (32%). The species enumerated are so closely related as almost to baffle definition. " oA z ie 7 me “3p ws) To Pe a aes SU ae ie le eral ENTOMOSTRACA OF MINNESOTA. 229 KEY TO THE SUB-GENUS CAMPTOCERCUS (VERUS). I. Beak pointed. A. Head depressed. a. Pigment spot larger than theeye.. . . . . . bisSerratus, 229 b. Pigment spot smallerthantheeye. . . . . . maecrurus, 229 Be Head directed forward; 2 2.005. ew te ss Peetirestris, 230 be “Beakrtrmncatepelow.g10 5. 0) seen et wae oe) > latirostris, 230 III. Beak cleft below or with a forward projection. A. Antennules shorter than the beak. . . . . . . Jilljeborgii, 230 B. Antennules longer than the beak. . . . . . . #£=Yrotundus, 230 Camptocercus biserratus Schoedler. PLATE LXII, Fia. 4. Is very nearly related to the next, from which it is distinguished chiefly by the fact that the pigment fleck is larger than the eye. Schoedler overlooked the fact that in C. macrurus there is a lateral line of scales on the abdomen, and relied upon that character to dis- tinguish this form. (Schoedler says that the pigment fleck in C. mac- rurus is Smaller than the eye, P. E. Mueller says they are nearly equal, while in our specimens they are much smaller or nearly equal.) If much variability is found, Schoedler’s species seems to rest on a slen- der basis. The basal spine of the claw, however, seems to be peculiar in sitting on a distinct prominence. *Camptocercus macrurus Mueller. PLATE LXI, Fias. 10, 10a. Lynceus macrurus— Lilljeborg, Schoedler, P. E. Mueller, Kurz, Birge, Herrick. This universally distributed species occurs in our larger bodies of water and is not rare, though hardly abundant. The body is long and nearly rectangular; the head strongly arched and keeled. The keel of the head is extended down the whole dorsal line. The dorsal line is moderately curved, while the shell is but slightly excavated below. The head extends into a blunt beak look- ing downward; the direction of the head is somewhat variable (from vertical to an angle of about 30 degrees). The eye is much larger than the pigment fleck; the antennules are shorter than the beak, and have one elongated terminal seta. The post-abdomen is very long and has numerous anal teeth as well as a lateral row of scales. The basal spine of the claws is large and serrate, the claw itself being nearly straight and armed with an increasing series of spines to be- yond the middle. The lateral scales of the post-abdomen are incon- spicuous. The shell gland is long. The antennules reach to almost ee a Se a 3 ee FOS eee eee eS jp eA, tas ta aed ote : Lend “at aaa L. MER eS 230 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. the end of the beak, are curved and bear a lateral flagellum. The first foot of the female has a sort of hook (branchial sac?). The la- brum is armed with teeth on the posterior face of the triangular pro- cess. The intestine is very strongly, almost twice, coiled. The lower margins of the valves are feebly spined for three-fourths their length, and armed with from one to four teeth at the angle. Length 0.8 mm- to 1.0 mm. Camptocereus rectirostris Schoedler. PLATE LXII, Fies. 1-3. Distinguished from the above, which it closely resembles, by the form of the head, which is less rounded and directed anteriorly. It hardly exceeds half the height of the body, The beak is sharp. I am not sure that Weismann’s figures (1. ¢., Plate XI, Figs. 13 and 14) really belong to this species, for the drawing of the post-abdomen does not agree with that of P. E. Mueller fully. Outline copies of the former are given in Plate LXIJ, Figs. 1 and 2. The male has a hook upon the first foot. Not yet recognized in America. Camptocereus latirostris Kurz. PLATE LXII, Figs. 5-6. C. lilljeborgii, P. E. Mueller (?). Closely allied to the next, but distinguished by the position of the head, which is a little less depressed, and, especially, by the truncate beak. The dorsal margin is convex and crested; the lower outline is also convex. The claws are toothed more as in C. macrurus than the following. The basal spine springs from the claw itself and not from the post-abdomen as in the next. Length 0.9 mm. to 1.0 mm. Camptocercus lilljeborgii Schoedler. PLATE LXII, Fias. 7-8. Head depressed, rounded in front; beak divided at the end by the extension of the fornices. The terminal claws are pectinate for their entire length, and the basal spine is seated on the end of the post- abdomen. This species, in the main, closely resembles C. macrurus. * Camptocercus rotundus Herrick. The second of the two species found in America is this short, strongly carinated form, which is known from a single gathering. It’ differs from all the above species, with which it agrees pretty well in shape, by its more compact form; high dorsal keel (which extends the entire length of the body); the long antennules, which extend far below the beak; and the somewhat pointed beak. The head is much as in R a a a a Fé Ag 4 “f a a ‘a ‘ 4 4 a at t ~ a 2 § 4 ENTOMOSTRACA OF MINNESOTA. 231 the last, but it is not certain that the beak is cleft, although it has a peculiar form (not indicated in the figure) near the end. The length is 0.7 mm. The terminal sete of the antennules are very unequal; but in most points, as in the armature of the post-abdomen, the details resemble ©. macrurus. [This is probably but a variety. ] GENUS ALONOPSIS Sars. This curious genus includes three species of small Lynceids which exhibit a combination of characters. The form of the beak and head is like that of Plewroxus, which the form and sculpture of the shell otherwise resembles. The back is extended more or less in a knife- like ridge above, thus resembling Acroperus, a resemblance heightened by the excavated lower margin. The form of the post-abdomen approaches that of Acroperus, but in that genus it is of about equal width throughout and in this it rapidly narrows. The internal organs and feet are of the typical lynceid form, while the antenne are as in Pleuroxus. . The type of the genus, A. elongata, is apparently much closer to Acroperus than the two species which have been identified in America. Shell sub rectangular, high, produced into a ridge above; lower margin convex anteriorly, concave behind; beak rather long; anten- nules slender; antennz with eight sete; abdomen long, narrowed toward end, incised at the extremity; claw rather large, with median spines and a basal thorn; third foot with a long bristle. Male smaller, without the carina above; orifice of sexual organs in front of the claw, which is removed from the anterior margin. The young are more elongate and (sometimes) have hexagonal reticulations instead of the usual strong diagonal strie. Motion slow. Alonopsis elongata Sars. Lynceus macrurus—Lievin, Zenker, Leydig. Alono elongata—Sars. Acroperus intermedius—Schoedler. The shell is wide, the upper margin forming an even curve, mani- festly angled behind; ventral margin nearly straight, ciliated through- out, with a single tooth behind. Fornices large; head narrow, not earinate. Post-abdomen compressed, truncate at the end, armed with a Series of marginal spines and of lateral scales; caudal claws large, with a single spine at the base and two median spines followed by a series of minute sete. This form I have never seen, and it seems somewhat doubtful that the following really belongs with it. SO ay eo SOK Da ee REP er I, Ae ee = o m » > - ae ENTOMOSTRACA OF MINNESOTA. 245 meshes. Post-abdomen short and wide, rounded at the end, orna- mented by seven or eight clusters of minute spines behind as well as a lateral row of scales. Length 0.43 mm. Hellich says the pigment fleck is larger than the eye and is farther from the end of the beak than from the eye. Alona pulehra Hellich. Sars ’61 (rectangula and lineata); Hellich ’74 and ’77 (lineata); Matile ’90. We are influenced by Matile in not recognizing A. lineata Fischer and substituting Hellich’s name. Alona lineata of Kurz is said by Matile to be A. costata Sars. Body small, elongate oval, truncate behind and of a pale color. Greatest height near the middle. The upper margin is rounded, the lower one somewhat sinuate, with setz of moderate length. The beak is short, reaching nearly to the level of the lower margin of the shell; the pigment fleck is one half the size of the eye, to which it is much nearer than to the end of the beak. Post-abdomen short, broad and tapering toward the end, truncate, armed with seven to eight large teeth; short caudal claws with a small basal tooth. Shell marked with distinct lines running horizontally. The ephippial females are recognized by a deep color and the greater elevation of the back Length 3.8 to 4.00 mm. I am unable to satisfactorily differentiate the species of this group. * Alona costata Sars. PLATE LX, Fic. 3. Alona lineata—Schoedler, Kurz, P. E. Mueller. Alona modesta—Herrick. We need not attempt to unravel the perplexing synonomy. As thus defined the species seems to be common in Europe and America. Shell quadrangular, widest behind the middle. Beak of moderate length. Pigment fleck smaller than the eye and midway between eye and beak. Antenne with only seven sete. Labrum small. The shell is strongly and coarsely striped parallel to the shell margins. Lower margin straight or concave, armed with rigid sets. Ccecum long. Post-abdomen rather short, acute and excavated at the distal end. Anal spines nine or ten, equal, with a secondary series of scales. Claws smooth, except for a basal spine. Length 0.55 to 0.65 mm. The claw of the male lacks the basal spine. The Minnesota representative of this widely distributed species differs in some respects. The lower margin is nearly straight and 246 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. rather sparsely hairy; the beak is blunt, but, on account of the spread- ing of the extremely wide fornices, does not appear so except under - pressure. . The beak reaches nearly to the lower shell margin. The antennules are narrow, one or more of the sete being elongated. The dorsal margin is either nearly straight or strongly arched behind; in either case the greatest height of the shell is back of the middle. The pig- ment fleck is large. The post-abdomen is just as in A. costata, but the lateral row seems to be of spines rather than fringed scales. The shell is marked by rather evident or indistinct lines. The form agrees pretty well with Schoedler’s figure, except that the posterior shell margin is much higher. The antenne have eight sete, but the last one is very weak. The terminal sete seem sometimes to be spined, as figured by Schoedler, but in some specimens they are perfectly smooth. There is a circlet of spines on the second joint of the setose ramus. There is a hair on the inner aspect of the protuberance of the labrum. The eye is somewhat nearer the pigment fleck than is the end of the beak. There seems to be no occasion for separating the American form (Plate LX, Fig. 3), in which the length varies between 0.41 mm. and 0.55 mm. The smaller forms have the back most rounded, while a specimen 0.55 mm. long will appear very like 4. quadrangularis. Males are elongate; hook of first foot strong, accompanied by a heavy growth of small spines; terminal claw of abdomen with a minute spine. * Alona porrecta Birge. Sub rectangular; ventral line nearly straight; valves marked by longitudinal strie; beak short. Post-abdomen truncate, with about twelve teeth, three or four of which at the end are larger, and a row of hairs above the teeth. Male similar. Length 0.34 mm. Distinguish- able from the following small species in the armature of the post- abdomen. The lower angle of the post-abdomen is acute. The claws are not serrate, but possess the basal spine. The post-abdomen is said to re- semble that of A. tenuicaudis in its armature, but not otherwise. This species is not enumerated by Professor Birge in his List of Crus- tacea Cladocera from Madison, Wisconsin [1891], and we are left in doubt whether the species is abandoned or not. Alona stagnalis Daday. ‘‘Rostro longisculo, paulum curvato, acuminato; macula cerebrali oculo minore} jabro processu mediali glabro; testa corporis longitudinaliter, manifeste striata, linea dorsali rotundata, margine ventrali medio parum arcuato, setas ubique me- ENTOMOSTRACA OF MINNESOTA. DAT diocres gerenti, postice angulum obtusum, inermem formante; cauda brevi, apicem versus rotundatum dilatata, margine dorsali utrinque serie marginali aculeorum 7-8 sensim minorum et pleuribus minimorum equalium armata; unguibus caudali- bus inermibus dente basali uno. Longit. fem., 0.4—0.48; alt. 0.18-0.22 mm.”’ While doubting the integrity of this species we are unable to place it and quote the author’s description. Alona elegans Kurz. PLATE LXII, Fig. 14. Form rectangular; back slightly elevated, posterior margin high, lower margin straight. Shell covered with minute striations spring- ing from the region of the attachment of the head shield. Head rather large, pigment fleck smaller than the eye. The antenne have eight sete anda circlet of spines on the second joint of the inner ramus, and a single thorn on its first joint. The post-abdomen is short and broad, rounded at the end, and is armed with about ten anal teeth and a lateral row of scales. Length 0.4 mm. to 0.5 mm. * Alona angulata Birge. Dorsal margin considerably arched, terminating in a more or less obvious angle at the hinder corner; the hinder edge is convex, as is also the front margin; the ventral margin bears plumose sete. Beak pointed, extending nearly to level of ventral margin of the valves. FYornices broad. Shell obviously striated diagonally and less obviously marked by cross lines. Post-abdomen broad, truncate; about twelve anal teeth, with a series of scales and hairs back of them. The pig- ment fleck is much smaller than the eye. Male smaller; beak shorter; post-abdomen with a lateral row of hairs; anterior feet hooked; sculpture less distinct. [Birge.] Length of female 0.4 mm.; male 0.35 mm. Whether Professor Birge still continues this species does not ap- pear, but it is dropped from the list of Madison Cladocera. Alona coronata Kurz. Hellich identifies this with his A. pulchra, but with Matile we re- gard this as doubtful. The resemblance to A. pulchra [lineata] is very close, the outline being identical. The lower margin is sparsely hairy. The beak is blunt. A half circlet of teeth ornaments the end of the middle segment of the inner ramus of the antenne, The macula is but little smaller than the eye. The post-abdomen is broad as in A, elegans, not narrowed at the end, but broadly rounded. The anal 248 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. spines are represented by clusters of hairs and there is a secondary series of scales. Kurz lays great stress on the fact that the intestine is flexed rather than coiled. Length 0.35 to 0.42 mm.; male 0.3 mm. Abdomen only armed with a series of delicate hairs. Alona barroisi Moniez. We quote the description of Alona barroisi Moniez (88). This form is very incompletely described from a single specimen. Itis said to be very small and finely striate. ‘*Tl est extremement petit, beaucoup plus bombe sur le dos qu’aucun autre Alona et la bord inferieur de la carapace est fortement arrondi, rappelant ainsi les Leydigia. Ce bord est muni de courtes soies; l’ocelle est environ moitie plus petit que 1’cil, l’appendice labial est large et arrondi sur les trois cotes libres; le post-abdomen est court, son crochet terminal depourvu d’anguillon a la base, les dents laterales en sont courtes et larges et il ya sur les cotes serie de plaques, la carapace est finement striee.’”’ Island of Terceira, Azores. It is doubtful whether it can be recognized. I venture to add a few memoranda respecting the long list of names which have appeared within this genus and which for various reasons are not included in the above list. Unfortunately the list is incom- plete and can only serve at best as a sort of guide to the perplexities of the synonomy. A. anglica Hellich is A. guttata. A. acanthocercoides of various authors is A. Leydigia. A. aculeatus is Alonella exigua. A. angusticaudata Hudendorff is Alonopsis latissima. A. balatonica Daday is A. Leydigia. . camptocercoides Schoedler is A. tenwicaudis. . esocirostris Schoedler is Graptoleberis. . excisa is alonella. . elongatus Sars is Alonopsis. . falcata Sars is Leptorhynchus. . grisea is Alonella. . glacialis Birge is a variety of A. guttata. . inornata Hudendorff is A. coronata. . msculpta is Alonella excisa. . leydigia is Leydigia. . lineata Fischer is unrecognizable. . latissima is Alonopsis. . ninuta Poggenpol is insufficiently described. . modesta Herrick is A. costata. . nanus is Alonella pygmea. . ovata Baird is uncertain. BeRERpRRaRR RRR ERR RRP PD ENTOMOSTRACA OF MINNESOTA. 249 . pygmea is Alonella. . parvula Kurz is A. guttata. . rectangularis is A. pulchra. . rostrata is Alonella. . reticulata Bd. is Graptoleberis. . striata is Alonella. . suleata is A. quadrangularis. . Spinifera Schoedler is the young of some species. socors O. F. Miller is uncertain. . tuberculata Kurz is A. guttata. . tuberculata Hudendorff is A. coronata. . transversa is Alonella pygmea. A, testudinaria is Graptoleberis. . verrucosa Lutz is A. guttata. bb ph hh hh bb be Section B, Alonella Sars. In this group are included small species with a combination of characters, forming the link between Alona and Pleuroxus. An obvious character is the fact that the shell is usually partly marked by oblique striz, which run in two directions: first, a set extending forward and upward from the lower posterior angle of the valves; second, a set springing from the anterior and Jower angle, running across the others. At the central part where these two series intersect, they each become zigzag; the result is a series of hexagonal markings, which may extend to the middle of the lower margin. The beak is short and the fornices broad; the shell is more or less rectangular, but somewhat elevated in the middle above. There are usually but seven setze on the antenne, or the eighth is a minute hair; on the ramus having the lateral setz one of the terminal sete is frequently reduced. In many cases the whole shell is marked by minute strie in addition to the proper markings, but this is also found in some species of the true Plewroxus. Kurz gives, as a character of Alonella, the presence of but a single basal spine to the claw of the post-abdomen; but P. E. Mueller figures two spines on the claws of one of his species (A. exigua), and Schoedler figures eight sete on the an- tenna of A. excisa. American specimens of A. excisa and of A. pygmea both certainly have a very minute eighth seta. There remains, there- fore, positively no point which can be relied upon to distinguish these little Lynceids from Pleuroxus or Alona. Perhaps, however, these Species, aS a group, may be recognized by what has already been said. Three species are found in Minnesota. 250 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. KEY TO THE GENUS ALONELLA. I. Rostrum long, bent backwards. a aes ik ea ease Palla setae a es II. Rostrum short. A. Lower posterior angle toothed. a. Shell more or less reticulate. * Reticulated areas minutely striate. pulchella, 250; excisa, 251 ** Reticulated areas smooth. + Flead:depressed. 2). Se tie eee 2 IST eos {+t Head horizontal. . =. . : - . grisea, 252 b. Shell marked by lines running aiaeoncilly ipaatd and backward, *..2 3-5). .- . . pygmeea, 253 B. Lower posterior angle aritpobie sell ier etteeiaralig striate. sStriata, 253 Alonella rostrata Koch. Lynceus rostratus—Koch, Lilljeborg, Schoedler. Alona rostrata—P. E. Mueller. Pleuroxus acutirostris—Birge. Pleuroxus affinis—Herrick. Body long, rapidly narrowed behind; dorsal line strongly arched in front toward the depressed head; the lower margin straight, with 0-3 small teeth at the angle. The fornices are broad, but the beak is sharp; the pigment fleck is but little smaller than the eye, to which it is three times nearer than to the beak. The post-abdomen is long, very much as in A. excisa, but longer. Length 0.4 to 0.5 mm. Schoedler says the lower margin is concave and the angle unarmed, a condition not inconsistent with specific identity, as can be seen in many other species. The shell seems to be variably marked, but most conspicuous are the diagonal, curved strize. Schoedler compares the sculpture to P. exiguus; Kurz, however, leaves the impression that only slight reticulation is present in the female. The male has the post abdomen narrowed, ornamented with clusters of hairs behind, and the small claws have no basal spine, while the genital opening is in front of the claws. * Alonella pulechella Herrick. PLATE XIII, Fics. 1-3. A minute form very recently obtained is described under the above name. Although closely allied to A. evigua, this species is more like Graptoleberis than any other member of the genus. It is the smallest of the Lynceids, excepting A. pygmea. The shell is high and rather strongly arched; the posterior margin is short and armed with four teeth below, wiih point in different directions as in Graptoleberis. The head is short and the antennules long. The pigment fleck is of > ae & ENTOMOSTRACA OF MINNESOTA. 251 moderate size, but smaller than the eye. The post abdomen is short, rounded below, and armed with sharp and small anal teeth, besides. which is an inconspicuous row of minute sete. The claw is very small, and has a single very minute tooth. The shell is marked by reticulations, which below are regular hexagons but above pass into elongated meshes, and finally on the beak and head become longitud- inal striations. The areas are lined as in A. excisa. Thus this species combines the form of abdomen of A. exigua with the teeth of Grapto- leberis and the markings of A. excisa. Length hardly 0.27 mm. Motion active. The specimen figured contained a single large ovum. The head may possibly have been somewhat protruded by pressure. Habitat, vicinity of Minneapolis. *Alonella excisa Fischer. PLATES XXII, Fie. 10; LXI, Fias. 6-7; LXIII, Fias. 10, 11. Lynceus excisus—Fischer. Pleuroxus excisus—Schoedler. ? Pleuroxus insculptus—Birge. This species is closely allied to Alonella exigua; yet that species. shows appreciable differences (which can hardly be claimed, per- haps, for Plewroxus insculptus). The various authors who have written of this Lynceid have all laid emphasis upon the sculpture of the shell, almost to the exclusion of other points in the description. Professor Birge has found a quite different form, apparently, which has the same peculiar markings; and even the common Alona oblonga has a part of the valves covered by minute striations. Schoedler’s figure of this species is unrecognizable; but, as identified by Kurz, the species seems undoubtedly the same that is common in shallow pools in Min- nesota, during autumn, and probably also in Massachusetts. The variations to which this species is subject are considerable and may account for the marked disagreement in the accounts of our dif- ferent authors. Schoedler gives his specimens a length of 0.20 to 0.25. mm., while Kurz says 0.85 mm. Birge gives 0.27 mm. for the length of Pleuroxus insculptus, and our specimens varied in the same gathering between 0.24 mm. and 0.40 mm. Schoedler figures three teeth at the lower posterior angle; Kurz says ‘‘several (4)’’; Birge describes one or two, and Minnesota specimens show gradual transitions from an in- conspicuous angle to three or perhaps four teeth. These teeth are the extensions of some of the strong ridges or crenulations which mark the shell. P. E. Mueller’s figures of the shell and abdomen of P. exigua would apply to our species perfectly, save the absence of minute striations; Kurz’s statements with reference to the differences. between these two forms seem to agree only in part with those of eae ee ee re SS Pe es ae 252 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. Schoedler. I must here express my suspicion that the Plewroxus aculeatus, P. exiguus and P. excisus all belong under this species. I ‘have seen a small form which lacked the fine striations; and there ap- peared to me to be, at times, a slight indication of a second series of hairs upon the post-abdomen. The form is oblong, truncate behind, variously arched above, but usually with a rather low, evenly curved dorsal contour; the lower shell margin is either nearly straight or convex in front and concave along the posterior third, and is heavily beset with very long pectinate bristles. The head is moderately depressed, with a very broad, blunt and short beak (in some positions this beak seems acute, but it is an optical delusion); the fornices are very broad, covering the antennules completely; seen from above the head is broad and truncate in front; the eye is larger than the large pigment fleck, which is nearer it than the end of the beak. The antennz have eight setz, the last of which is minute; the five spined ramus has a strong thorn on the end, and the inner terminal seta is reduced. The post-abdomen is rather broad and truncate or somewhat rounded below; its length is very variable, being short in small individuals; its form is subject to concomitant variations. Theseven to eleven anal spines extend in a series of minute bristles above the anus. The lower posterior angle of the shell bears one to four teeth; the marking consists of wavy ridges and strie, pro- ducing, by the crossing of two sets springing from the two lower angles, a reticulation covering more or less of the entire shell. The head-shield and the spaces between these markings are densely striated. Color yellowish, often opaque. Length 0.24 to 0.40 mm. At times abund- ant. Birge alone has seen the males; his description agrees with Kurz’s account of the male of 4. exigua, save that the former speaks of spines, and the latter of thorns, along the post abdomen. Alonella exigua Lilljeborg. Lynceus exiguus—Lilljeborg, Leydig, Fric. Pleuroxus exiguus—Schoedler, P. E. Mueller. 2 Lynceus aculeatus—Fischer. Aside from the differences in the male sex as above indicated, this form is said to have a convex lower margin, a rounded post-abdomen, and the pigment fleck nearer the end of the beak than the eye. The absence of the fine striation, finally, is the most marked characteristic: Length 0.30 to 0.83 mm. Not identified in America. (?) Alonella grisea Fischer. This species is included here on the authority of Kurz. The shell may or may not be toothed at the lower corner, and is partly lined and partly reticulate; but the only character which at all separates this ENTOMOSTRACA OF MINNESOTA. 253 species from the above seems to be the position and form of the head, which is said to be blunt and nearly horizontal, as in Camptocercus rectirostris. Is this a transition to Graptoleberis? * Alonella pygmzea Sars. PLATE LX, Fia. 7. Pleuroxus transversus—Schoedler. Alonu transversa—P. E. Mueller. Lynceus nanus—Fric. Alonella pygmza—Kurz. The form is rotund, much like species of Chydorus in the highly arched dorsal outline; the beak is rather short and depressed; the lower outline of the valves is very convex in front, and barely sinuate behind, where it terminates in a minute spine. The shell is marked, as in no other Lynceid, by lines running diagonally backward, and only on the lower part reticulated, if at all. The post-abdomen is short, broad and rounded below; the claw has a single basal spine. Length 0.20 to 0.28 mm. This is the smallest member of the Cladocera. In form it so nearly resembles Chydorus that upon first sight the writer took it for a member of that genus. Our one specimen measured 0.25 mm. The shell is marked by plica- tions rather than strie, which arch over the back. Alonella striata Schoedler. This species is said to resemble A. exigua in habit and sculpture of shell; the form is quadrangular and not greatly elevated in the middle; the lower margin is nearly straight and fringed with bristles; the posterior angle is rounded and unarmed. The antennules with their sete extend beyond the beak; the pigment fleck is smaller than the eye and half way tothe beak. The post-abdomen is long and nar- rowed toward the end; there are seven or eight anal spines, and two spines on the terminal claw. Length about 0.5 mm. SUB-GENUS PLEUROXUS. Section A, Pleuroxus (verus) Baird. This group of Lynceids is most obviously defined by the long. beak, formed by the extension of the chitinous covering of the head. (There is rarely a beak in the sense of that word as applied in the case of Scapholeberis or Daphnia, but the antennules are simply attached to low prominences on the under side of a broad shield-like projection of the shell.) This beak-like projection is acute and often long and either curved backward or even bent forward. The fornices, or lateral 254 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. projection of the head-shield, are narrow. The form varies much, but. is almost always very strongly convex above, and the posterior margin is thus only a fraction of the whole height of the animal. In some American species the body is very much elongate, and these also depart from the characteristic habitus of the genus in having strong longitudinal striz instead of reticulations. The lower posterior shell angle has teeth which, in a few cases, extend across the entire posterior margin. The post-abdomen is slender, usually truncate and armed behind with a single set of sharp teeth on either side; the terminal claw has usually two spines and may be serrate. The male has a shorter beak, the post-abdomen is more or less modi- fied, and the first foot has a powerful hook. The winter eggs frequently have a true ephippium; and sometimes this structure is like that of Chydorus, toward which the round forms of this genus seem to lead. There are upwards of a dozen valid species, several of which are American. KEY TO PLEUROXUS VERUS. Beak not curved forward. A. Shellreticulate . . . . . . . hastatus, 254; (?) stramineus, 255. B. Shell smooth, except upon the front margin. . . . . . adunctus, 255. C. Shell striped. a. Shell very long and low. * With one tooth below. . . . .) gracilis, 257 ** Without a tooth; female with a ipa upon hie first foot. hamatus, 257 b. Shell high. * The whole posterior margin of the shellspined. . . . truncata, 258 ** The lower angle of the shell spined. + Antenne with eight sete; the anterior margin of the valves toothed. eee OM ~ eo. ee he a, Centiculatus; 256 tf} Antennze ith seven es i hes Teak ey ae MSE ee bn, eed ee ee Beak procurved (Rhypophilus). A. Shell reticulate (either strongly or quite faintly). . . . personatus, 259 B. Shell striped. a. The posterior margin of the shell toothed. . . . . . procurvus, 258 b. Only the lower angle of the shell toothed. . . . . . Uuncinatus, 259 (Not noticed inthekey. . ....... . . . trigonellus, 255) Pleuroxus hastatus Sars, PLATE LXII, Fie. 16. Pleurozus levis—Sars, Form somewhat oval, dorsal line strongly curved, posterior mar- gin short, with a tooth below; head short, beak very long, straight- ish; shell obscurely reticulate. Post-abdomen very long, narrow, ENTOMOSTRACA OF MINNESOTA. 255 with small teeth; claw with two basal spines. Color corneous. The sculpture consists of faint reticulations. The ephippium forms a truncation of the upper part of the shell. Length 0.50 to 0.55 mm. The male has a shorter beak; the first foot has a weak hook; and the Spermatozoa are spherical. Pleuroxus stramineus Birge. This form is the American representative of the preceding, if not identical with it. Birge mentions minute strie in the meshes. P. stramineus is said to be lower than P. hastatus, while its beak is shorter. Undoubted specimens of P. denticulatus exhibit the same differences, an increase in the convexity of the shell accompanying an increase in the length of beak. The form of the abdomen appears nearly identical, if we compare P. HE. Mueller’s Plate IV, Fig. 18, with the outline given by Birge at Plate II, Fig. 11. The color in both is deeps especially during the period when the winter egg is forming. The direction of the reticulations is said to differ, but P. E. Mueller’s figure does not furnish positive evidence of this. Length 0.6 mm. ~leuroxus trigonellus O. F. Miiller. Lynceus trigonellus—O. F. Miller, Lievin, Lilljeborg, Leydig, Fric. ? Pleuroxus ornatus—Schoedler. Dorsal line strongly arched; the beak rather long, straightish, pigment fleck smaller than theeye. Shell faintly reticulate, the mark- ings consisting of transparent ridges. Post-abdomen widest in the middle, attenuated slightly toward the end, which is truncate; claw large, with one long and one very small basal spine. The anal margin of the post-abdomen has a series of small spines, and the lower shell-margin is hairy. The post-abdomen of the male is somewhat as in Orepidocercus, and densely hairy; the first foot has a moderate hook. To judge from Kurz’s statements, P. ornatus Schoedler is not specifically distinct. Not yet identified in America. Pleuroxus adunctus Jurine. Monoculus adunctus—J urine. Very like P. trigonellus, but with the back more strongly arched. ‘The anterior part of the shell is striped. The beak is shorter than in P. trigonellus, but no other permanent differences are discoverable. The temptation to believe this a mere varietal form of P. trigonellus is great. Indeed, four species (the two here noted, P. bairdii and P. denticulatus Birge) are very nearly related. The ephippium, where known, is marked by minute punctation and a darker color. NPs mal ee eee re ee. ee eo a Ey £ ee a ly ee 2 oe * res ie Pas z ie t v vi ~~ > “4 Ra, A f : t Ce the it ENTOMOSTRACA OF MINNESOTA. 3815 GENUS ERPETOCYPRIS Brady and Norman. 1889. ‘General characters of the animal closely approaching those of Cypris; but the sete of the third joint of the lower antenne are short, not nearly reaching the apex of the terminal claws, and are not plumose. The second pair of jaws have branchial plates as in Cypris. The power of swimming is lost, and the habits of the animals, which creep along the bottom, are thus very different from those of Cypris.”? (Brady and Norman). Erpetocypris minnesotensis (Herrick.) PLATE LXXII, Fias. 2-2h. 1887.—Cypris minnesotensis C. L. Herrick (86), p. 28; Pl. IV, Fig. 2. Length 1.60 mm. This species is closely related to Erpetocypris fasciata (O. F. Miller). In F. fasciata the caudal margin of the abdominal ramus is smooth» but in HZ. minnesotensis it is pectinate. In /. fasciata the length is three times the width, but in F. minnesotensis the length is two and one-half times the width. The figures and the following description are from Professor Her- rick (86). ‘‘From any of the American species it is at once known by the great proportionate length of the valves, which are about two and one-half times as long as broad. Lower margin nearly straight, gently sinuous near the middle, dorsal margin gently curved, highest back of the middle, then gently curved; color light, with two inconspicu- ous dark transverse bands on either side at about the anterior and posterior thirds; scattered hairs upon prominences are found near the margins. Antenne (antennules) slender, seven-jointed, apex with two very long and one short spine, penult segment with tour long setze, antepenult segment with two long plumose sete above, preceding segment with shorter setz; second antenn with the apical segment very short and armed with one (?) serrate claw and a seta, the preced- ing with two claws and a few short sete, antepenult segment with three (four?) shortish sete, not reaching end of claws; mandible with strong lobed teeth and a Jarge palp; first foot with a large claw; sec- ond foot slender, ending in a small hook with a single weak seta; cau- dal stylets rather short and wide, with two strongly serrated claws, the other spines being obsolescent (?); posterior margin serrulated. Lucid spots of the shell seven in number, two being minute. Length of shell 1.6 mm.’’ Habitat: Minnesota (Herrick, 86). 2 at i Vk a Pe a: Sa ae ak ale “a CaaS . 4 D> a ae ee 4 Fy t 316 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. Erpetocypris barbatus (Forbes. ) PLATE LXXVII. 1879.— Candona ornata (?) C. L. Herrick (83), p. 113; Pl. XX, Fig. 1. 1893.—Cypris barbatus 8. A. Forbes (67a), pp. 244-246; Pl. XX XVII, Figs. 2-3; Pl. XXXVIII. This, which is probably the largest freshwater ostracode, is known to me only through the paper of Professor 8. A. Forbes. The follow- ing description, as well as the figures, is copied from his paper. ‘‘An extremely large, very hairy, oblong Cypris, with rounded ends and dorsal and ventral margins nearly parallel. Length 4.0 mm. Width 1.6mm. Depth 2.0 mm. A very little deepest at hind end of hinge margin. (Depth across eye 95 per cent of greatest depth. ) ‘Dorsal margin about straight for a great part of its length, the ventral margin very slightly emarginate or sinuate at its anterior third. The anterior end broadly and smoothly rounded, more obliquely above than below, the posterior somewhat obliquely rounded, the ventral margin being thus nearly half as long again as the dorsal. Seen from above the shape is symmetrical, a slender oval, a little more flattened at the sides behind than before; thickest, con- sequently, before the middle. **Color a dirty yellowish brown in alcohol, with a reddish-brown patch on either side above and behind the middle. Surface of valves opaque, very minutely roughened, and well covered with conspicuous hairs, which give this Cypris [ Erpetocypris] a decidedly hairy appear- ance to the naked eye. Hairs longest before and behind and length- ening generally towards the margin, where they project as a fringe, the most prominent part of which is a row of hairs borne on slender conical tubercles within the margin of the valves, The valves are equal and the shell fairly full, but not plump. ‘‘Anterior antenna with the basal segment obliquely channeled, partially dividing it into two, the distal part of which bears a single bristle on its superior surface, and two long, more slender ones, springing together from tip of the ventral surface. A short, subquad- rate second segment bears a single seta, about as long as the segment, on the dorsal surface, near the tip. From the distal end of the fol- lowing segment spring two long, slightly plumose sete, one dorsal, one ventral, the former much the longer. The fourth segment bears at its tip four long sete, two of which arise from the ventral angle and two from the outer dorsal. The following segment is similarly armed, and the distal extremities of the sixth and seventh are densely set with long plumose seté forming a stout fascicle, which extends beyond the end of the antenna a distance equal to the length of the antenna itself. sip eclietn Sy as I AA Vi EE NI 8 kta ire ig ie ‘ . A rl ENTOMOSTRACA OF MINNESOTA. 317 ‘The terminal segment of the palp of the first maxilla is a little more than a fourth the length of the basal, the latter with one subter- minal bristle without, and several terminal ones. Tip of last segment with two stout, curved, claw-like set, and four or five smaller, softer ones. Outer lobe of maxilla proper reaching to tip of first segment. of palp, nearly equaling it in diameter, also with two curved claws, shorter but much stouter than those mentioned above, three-fourths as long as the lobe itself. Besides these, two smaller sete and three or more sub-terminal ones, two of which are smooth, like the terminal group, one strongly plumose. A single plumose seta also springs from near the base of the concave surface of this lobe. The second and third lobes similarly armed at the tip, but with a larger number of curved sete, all of which are soft. Two of these, on the short inner lobe, are much longer and stouter than the others, and project directly backwards. The base of this lobe bears two plumose sete about as long as those just mentioned. The length of the inner lobe is half that of the outer, the middle one being intermediate. ‘“‘The second maxilla with about 12 terminal sets, which diminish in length inward, most of them slightly plumose, and two long slender setae, one springing from the middle of the inner margin and the other from the base. Palp thick, slender ovate, twice as long as the masti- eatory lobe, fringed with a soft silky pile. and bearing three more or less plumose setee at its tip, the middle one of which is the longest. Branchial lobe very small, semicircular, with three fully developed plumose sete nearly as long as the palp, and two much shorter ones, one delicate and smooth, the other stout and plumose. ‘“The basal segment of the second antenna trigonal, with one mod- erately long hair beneath, and two of similar length springing together from the inner side of the apex. The second segment subcylindrical, with two hairs diverging from the middle of the outer side of the apex, the under one of which is very short and weak, about as long as the third segment is wide, while its companion reaches about to the tip of that segment. On the inside of the tip of the second segment is another hair, similar to the above, and of about the same length. The third segment bears, at the union of its basal with its middle third, on the under side, set beyond a slight tooth-like projection, a jointed olfactory club, whose length is about two-thirds the diameter of the segment. Otherwise this segment bears no hairs except at the tip, where, upon its inferior angle, is one long, stout hair, reaching beyond the tip of the last joint, and upon its inner surface a fascicle of five plumose hairs, the four longer of which are curved and parallel, while the fifth is short and straight. The third segment is slightly longer than the second and about two-thirds as thick. The fourth segment is three- 318 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. fourths the length of the third and about two-thirds its diameter, slightly enlarged at the middle, where it bears, on the under side, a group of three long hairs, and upon the upper side two shorter ones. At the tip of the segment are a group of three long plumose hairs and a stout, curved, concave, acute claw, nearly three times the length of the last segment, doubly dentate on both edges. At tip of last segment the usually strong, curved bidentate claws, five in number, three of equal length, as long as the two last segments of the antenna, and two others about half that length. ‘‘Mandible with a row of six dark corneous teeth, more or less bifid, the series continued in an irregular cluster of tooth-like spines, and terminating in two highly plumose setz. The series of teeth with numerous accessory smaller teeth and spines, anf tw o transparent la mellze—slender, but as long as the teeth themselves—inserted between the first and second and second and third series, respectively. The lat- ter lamella is recurved and serrate on its concave edge. Basal segment of palp longest, the third next, second and fourth sub-equal in length, the second as broad as the first. The latter bears at its posterior tip three plumose set of unequal length, in a cluster, and a fourth larger, stouter, decurved articulate one, inserted on the outer side of the tip of the segment, The second segment has in front a group of three slender sete inserted a little behind the tip; and opposite to them upon a stout tuberosity another group of three long equal set, to which a fourth stands in the same relation as on the preceding seg- ment. On the third segment is a group of five sete similar to those on the anterior margin of the segment preceding, and, in addition, a circlet of six, attached around the posterior and inner margin of the end of this segment. At the tip of the palp are three curved claws, averaging as long as the two preceding segments together, with some slender sete intermixed. The so-called branchial appendage is about as long as the basal segment of the palp, and bears four stout plumose setze with a small accessory seta in front. ‘‘Rirst leg with basal segment columnar, distal portion partially separated, without hair or bristle. Second segment cylindrical, its surface smooth except for numerous transverse rows of exceedingly fine short sete, present also on the two succeeding segments of this leg. A stout bristle at anterior distal angle. Third and fourth seg- ments nearly equal (the third, however, somewhat the longer), together slightly longer than the second, the length of each about twice its transverse diameter. The third with a single apical hair at the ante- rior angle, and the fourth with but two, one of which is as long as the segment itself, and the second about half that length. -Terminal seg- ment with a very long, slender symmetrically curved, regularly taper- ENTOMOSTRACA OF MINNESOTA. 319 ing claw, with two short soft sete springing from its base. The entire claw somewhat longer than the last three segments conjointly. ‘‘Oaudal rami long and slender, slightly sinuate, the transverse diameter of each not more than one-twentieth its length; the basal fifth, however, considerably thickened. Rami smooth, except poste- riorly, where the margin is closely set with stout, short spines, length- ening toward the distal end of the ramus. Terminal claw slightly curved at the tip, contained two and a half times in the length of its ramus. Subterminal claw nearly two-thirds the length of the terminal, also slightly curved. Claw-like seta almost immediately above the latter, more slender, but two thirds its length. Besides the above, a short slender seta springs from in front of the base of the termina] claw. ‘‘The first and last segments of the second pair of legs sub-equal, each two-thirds the length of the second; basal segment straight, its length five times its width, with three slender setz, one borne upon the middle of its exterior side, and two near the apex, opposite each other. Second segment slightly curved, with a single slender seta near the apex, on its outer margin. Third segment with two terminal sete, one nearly straight, claw-like, about three-fourths the length of its segment, and the other curved and blunt.”’ Habitat: Yellowstone River, Yellowstone Park, Wyoming (S. A. Forbes); (?) Minnesota (Herrick). To my mind Candona ornata Herrick belongs here. But since the figure given by Professor Herrick is about all I have to base my opinion upon, it is not thought wise to enforce this opinion upon the public. GENUS CYPRIS O. F. Miiller, 1785. ~In both sexes the antenna is five-jointed. The natatory sets on the third extend to the tip of the terminal claws. The mandibular palp does not extend beyond the tip of the man- dibular teeth. The branchial plate of the first maxilla is large, bearing stiff, plu- mose sete. The first mandibular process is armed with two biarticu- late thorns. The second maxilla bears a branchial plate. The second foot resembles that of Cypridopsis. The abdominal ramus is stout, aud terminates with two more or less stout claws, in front of which occurs a short and behind which a long seta. Males are unknown; propagation parthenogenetic only. 320 GEOL. AND NAT, HIST. SURVEY OF MINNESOTA. Cypris fuscata Jurine. PLATES LXXI, Fias. 41-46; LX XII, Fias. 7-7p; LX XVI, Fia. 9. | 1820.— Cypris fuscata Jurine (98), p. 174; Pl. XIX, Figs. 1-2. 1837.—? ‘‘ adusta Koch (102), H. II, 3. 1838.— ‘* galbinea Koch (102), H. XXI, 19. 1844.— ‘ fuseata Zaddach (234), p. 32. 1850.— ‘‘ fusca Baird (5), p. 154; Taf. XIX, Fig. 7. 1850.—Candona hispida Baird (5), p. 161; Taf. XIX, Fig. 4. 1853.—Cypris fuscata Lilljeborg (118), p. 114; Pl. X, Figs. 6-9; Pl. XII, Fig. 5. 1868.— ‘ usca Brady (18), p. 362; Pl. XXIII, Figs. 10-15. } g 1887.— ‘‘ dugesiC. L. Herrick (86), p. 26; Pl. IV, Fig. 7. 1888.— ‘‘ fusca Sostaric (202), p. 47. 1889.— ‘ uscata Brady and Norman (31 . 73; Pl. XII, Figs. 3-4. f y » P. 73; , Fig 1891.— ‘‘ fuscata Wenzel Vavra (221), pp. 98-99, Figs. 33, 331-333. 1894.— ‘* fuscata C. H. Turner (215), pp. 16-17; Pl. VII, Figs. 41-46. 1894.— ‘ fuseata C. H. Turner (216). Length of the female 1.40 mm. to 1.50 mm. Height 0.9 mm. Width 0.67 mm. to 0.73 mm. The greatest height of the animal is about two-thirds of the length, while the greatest width is less than the height. The color is greenish brown. ‘The shell usually has attached to it furfaceous mat- ter, which Professor Brady thinks is desquamating epidermis. Viewed from the side the cephalic third of the shell is wider than any other portion. The caudal, dorsal and cephalic borders are con- vex. The cephalic and caudal margins have a narrow hyaline edge. The valves are not very transparent and are covered with short, seat- tered hairs. Muscle impressions near centre of the valve, about seven. Viewed from above the shell is oval, rounded behind and bluntly pointed in front. The greatest height is in the middle. The natatory sete of the antenne extend to the tips of the terminal claws. The terminal claws are stout, curved and longer than the last two joints. The distal half of the inner margin of each claw is pecti- nated with a double row of fine teeth. The two enlarged spines upon the first mandibular process are toothed. The extremity of each spine and the two adjacent teeth are blunt. The first foot is five-jointed, the third and fourth joints being dis- tinct. The terminal claw is long and stout, longer than the combined lengths of the last three joints. The second joint is stout and about as long as the combined lengths of the next two joints. The terminal claw of the second foot (Fig. 43) is about twice as long as the terminal joint. ENTOMOSTRACA OF MINNESOTA. 321 The feebly-curved post-abdomen (Fig. 46) is stout and short. The terminal claw is a little more than half as long as the abdominal ramus. The adjacent claw is about three-fourths as long as the ter- minal claw. Habitat: Cincinnati, Ohio (Turner, 213); Guanajuata, Mexico (Herrick, 86); Albuquerque, New Mexico. Cypris virens Jurine. PLATE LXXIV, Fias. 3-3e. 1820.— Monoculus virens Jurine (98), p. 174; Pl. XVIII, Figs. 15-16. 1838.—Cypris qibberala Koch (102), H. X XI, 20. 1844.— ‘‘ virens Zaddach (234), p. 35. 1844.— ‘‘ pilosa Zaddach (234), p. 36. 1850.— ‘‘ ¢ristriata Baird (5), p. 152; Taf. XVIII, Figs. 1, 1a-1i, 2-3. 1851.— ‘‘ ornataS. Fischer (63), p. 157; Pl. IX, Figs. 7-10. 1853.— ‘‘ virens Lilljeborg (118), p. 117; Taf. VIII, Fig. 16; Taf. IX, Figs. 4-5. 1868.— ‘‘ virens Brady (18), p. 364; Pl. XXIII, Figs. 23-32; Pl. XXXVI, Fig. 1. 1868.— ‘‘ pubera Fric and Nekut (70), p. 46, Fig. 26. 1870.— ‘‘ ventricosa Brady and Robertson (33), p. 12; Pl. IV, Figs. 1-3. 1872.— ‘* pubera Fric (69), p. 226. 1874.— ‘* virens Brady, Crosskey and Robertson (30), p. 124; Pl. II, Hibs 27-28. 1887.— ‘‘ Helena Moniez (135), p. 2. 1887.— ‘* virens C. L. Herrick (86), pp. 24-26; Pl. VI, Fig. 3. 1889.— ‘‘ virens Brady and Norman (31), p. 77. 1891.— ‘‘ virens Wenzel Vavra (221), pp. 102-104, Fig. 3; Figs. 4, 41, 47, 44; Figs. 5, 51-52; Figs. 36, 361-364. Only once have I encountered an American form which I supposed was Oypris virens. Then the specimens were accidentally destroyed before accurate drawings were made. Mr. Deming, however (Her- rick, 86), claims to have found this species to be quite abundant at Granville, Ohio. The following description is due to Mr. Deming. I have taken the liberty to omit much that is merely generic and to add, in brackets, some specific characters. ‘*Valves sub-reniform, the two ends almost equal, the dorsal side evenly curved, the ventral side sinuated, highest in the middle. The valves are covered with minute hairs. The hinge-line is sinuated and unbroken. The outer part of the shell is slightly lined. The shell as seen on end is oval; seen from above, oblong-ovate. Lucid spots, about seven in number, are found in about the centre of the valves; these are oblong and irregular in shape, often pointing towards the ventral margin. Isolated spots are found near the dorsal side. The color is olive or yellowish green, with dark brown spots near the dorsal margin and scattered throughout the shell * * * * * * x [The two biarticulate spines on the first mandibular process of the first maxilla are smooth. ] 322 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. ‘‘The post-abdomen forms two long, movable rami, which are well developed and terminated by two claws of unequal length, and in fine Specimens are serrated on their inner edge near the apex. The rami themselves are also serrated.’’ [In European specimens and in speci- mens taken by the present writer to belong to this species the abdomi- nal rami are not serrated. | Mr. Deming claims to have found the male of Cypris virens. Ihave reason, however, for supposing that he has confounded the males of some other species (perhaps C. crena) with Cypris virens. Habitat: Granville, Ohio (Herrick, 86). Cypris perelegans Herrick. PLATE LXXIII. 1887.—Cypris perelegans C. L. Herrick (86), p. 27; Pl. III, Figs. 7-12. 1894.—Cypris perelegans C. H. Turner (216). Length 3.60 mm. Height 1.72 mm. Width 1.40 mm. ‘*Carapace of largest size, elongate sub-oblong, sides nearly parallel, upper margin nearly straight, lower outline with two sinuses and two slight convexities, produced to form a slight tooth behind; greatest height at one-fourth the length from the posterior, equal to less than half the length; width greatest somewhat in advance of the middle, about four-tenths the length; color clear, pale yellow, with a well-de- fined pattern in deep brown, pattern consisting of a sigmoid band crossing the middle of the valves, giving off spurs at each flexure, and sundry other spots, as well as an anterior marginal band; surface shining, minutely dotted, slightly hairy at margins; lucid spots con- sisting of two large irregularly pentagonal approximated spots, with three smaller ones grouped below; appendages very Similar to C. virens; ~ antennse seven-jointed, slender, basal segment very large, third elongated, four succeeding nearly equal in length, fourth and fifth segments each with two long sete above, sixth with four long and one shorter sete, apical segment with four very long sete, fifth segment with two sete of moderate length below; antennules (antenne) slender, apical segment with two serrate claws and two slender sete, fourth (antepenult) segment the same, third segment with four long and two shorter sets, second segment with six long pectinate sete reaching to end of terminal claws; labrum with claw-like appendages bearing seven teeth, the inner being double, medianly the labrum appendaged with pectinate plates; the mandibles furnished with six strong teeth, two pectinate sete and several small spines, the palp being well-de- veloped; first maxilla with short lobes, the anterior of the one-jointed lobes with four very strong toothed spines; first foot with five seg- ments, the apical one being very small and bearing a single very long Pe LET eh Se TN ee eee 4 ieee” ah ate , 4 Says j 1’ U ENTOMOSTRACA OF MINNESOTA. 323 serrated claw, the third and fourth are equal and much more slender than the second; second foot slender, apical segment with two small claws and one delicate seta, caudal stylets elongated, narrow, serrate behind, with two straight, unequal serrate claws, lateral spine sub- terminal.’’ (Herrick, 86.) Habitat: Mobile, Ala. (Herrick 86.) Cypris altissimus Chambers. PLATE LXXIX, Fies. 10-13. _ 18—.—Cypris altissimus Chambers (41), pp. 152-153, Fig. 2. 1887. —Cypris altissimus C. L. Herrick (86), v. 27. Length 1.26 mm. Height 0.63 mm. ‘‘Valves oblong, slightly subreniform, highest about the middle, rounding regularly before and behind; the side view resembling some- what Baird’s figure of ©. tristriata, but less distinctly reniform, perhaps rather resembling in the form of the dorsal margin Cypridopsis vidua; it is, however, much more elongate in proportion to height. Brady’s figure of C. virens (= C. tristriata Baird) is alittle nearer to this species, but is too distinctly reniform. OC. virens also agrees with this species in the number (seven) of the lucid spots, and approaches it in their position on the shell, and in relation to each other, but they differ in shape. In this species, the extremities are more nearly equally rounded than in virens, the dorsal margin being evenly rounded before and behind the middle, and the ventral likewise, both before and be- hind the slight sinuation in the middle. But the anatomy of the ap- pendages differs more decidedly from that of virens, as will be seen by a comparison of the following account with Brady’s figures. Superior antenne with only twelve instead of fourteen long set, arranged as follows: There are two short sete (one longer than the other) from the third joint, which has none in Brady’s figure; two short and two long ones from the fourth joint, where virens has four long ones; three long ones and one shorter one from the fifth joint, which in virens has four long ones; four long ones from the sixth joint, where virens has only three, and three long ones and one short one from the last joint, where virens has three long ones. In the inferior antenne similar differences are found, and in the mandibular palpus even greater ones. The feet of the first pair appear to be identical in the two species, ex- cept that this species has a short seta on each of the joints three and four, which are not represented in Mr. Brady’s figure. His figure, however, shows one seta more on each of the joints two and three of the feet of the second pair than I find in this species, which likewise is much smaller than C. virens, being only one-twentieth of an inch long and one-fortieth high instead of one-fourteenth of an inch long and 21 6 PS PEPER aR MEN SO LPL Ge a tte? Bean a 324 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. one twenty-fifth high, as in virens. In ventral and dorsal view it also resembles virens. Surface smooth pubescent, with minute punc- tures. Color bright deep green.’”’ (Chambers. ) This species has not been seen by me. It certainly is very closely related to Cypris virens, and may prove to be that species. For the present, however, it is thought best to regard it as a distinct species. Habitat: Pond fed by melting snow, Mount Elbert, Colorado. A1- titude, about 12,000 feet. (Chambers, 41.) Cypris herricki \Turner. PLATES LXVII, Fias. 1-10; LXVIII, Figs. 40-42; LXIX, Fias. 32-39. 1892.—Cypris Herricki C. H. Turner (212), pp. 71-73; Pl. II, Figs. 1-10. 1893.—Cypris Herricki C. H. Turner (213), pp. 11 15; Pl. I, Figs. 33-39; Pl. a Figs. 40- 42. Length 3.0 mm. Height 1.70mm. Width 1.43 mm. In a lateral view, the shell is sub-triangular, highest near the mid- dle. The ventral margin is straight, excepting at the cephalic ex-— tremity, where, after a shallow concave notch, the margin is convex. ‘The remainder of the margin is strongly convex. From the above described ventral notch, a well defined, feebly convex, line passes dorsad to the opposite margin. That portion of the shell which lies cephalad of this line is usually curved laterad. From within the ‘cephalic and caudal extremities of the valves numerous hairs pro- trude. In a dorsal view, the shell is sub-fusiform, being widest caudad of the middle. At their caudad extremity the valves are slightly divari- cated, while at their cephalad extremity they are closely approximated. ‘The shell is covered with fine reticulations and minute hairs. In addi- tion to these, it is marked with conspicuous dark green bands. These ‘bands are arranged as follows: One, parallel to and almost adjacent ‘to the mesal border of the shell, extends from the caudo-ventrad angle ‘of the shell dorso-cephalad almost to the cephalad extremity of the valve. There it divides. One portion continues in the same course to the cephalo-ventral extremity of the valve. The other, turning ‘laterad, passes ventrad for a short distance and terminates in a sharp point. At the origin of this line there is a large, convex blotch, which ‘extends ventrad a short distance. Near the centre of the figure several bands fuse in such a manner as to form a hollow, sub-square figure. From the cephalo-dorsal corner of the square a tongue passes ventro- caudad into the square. The length of this tongue and the angles it makes with the sides of the square vary slightly in different individ- uals. Usually it extends almost to the centre. From this same angle of the shell a band projects ectad. After passing cephalad a short ae ¥ = ENTOMOSTRACA OF MINNESOTA. . . 325 distance, this band forms a convex curve and passes caudo-dorsad almost to the margin of the shell. From the caudo-dorsal angle of the Square a Short band passes dorso caudad and fuses with a broader band which passes caudad, approximately parallel to the dorsal margin of the shell. From this same corner another band passes caudo-ventrad almost to the caudal margin of the shell. This band is approximately parallel to the band just described. From the caudo-ventral angle of the square a band passes caudo-ventrad almost to the caudo-ventral extremity of the shell. In the caudal portion of its course this band eurves dorsad, otherwise it is approximately parallel to the band last described. From the cephalo-ventral angle of the square, a short band projects ventrad and then broadening, forms a boot-shape band. The short heel of this boot projects caudad and terminates in a point, the long toe extends cephalad and terminates bluntly. From the same corner of the square, a second band projects cephalad to about the ‘level of the toe of the boot. There it fuses with a spike-shaped band which extends cephalo-ventrad from near the cephalo-dorsal angle of the square to about the cephalo-ventral extremity of the shell. The head of the spike is at the caudo-dorsal extremity of the band. The two bands fuse near the head. The number of lucid spots is about eight. They are situated in the centre of the valve and ordinarily are inclosed within the square above described. Viewed from the ventral surface one valve overlaps the other in front. The contact line is sinuous, being laterally convex at the mid- dle. Viewed from the end the shell is oval in shape, the greatest width being near the dorsal surface. Antenne slender; the natatory setz on the distal extremity of the third joint reach almost or quite to the tip of the long and slender terminal claws. The mandible is stout. Among other sete, the antepenultimate joint of mandibular palp bears a short, pectinated, dagger-shape seta; so does the penultimate joint. The two biarticulate claws on the first mandibular process of the first maxilla are smooth. The extremity of that same process bears two sete as long as the biarticulate claws; one, which is curved and smooth, is situated at the outer angle and the other, which is straight and pectinated, is situated about the middle of the extremity. The terminal claw of the first leg is almost as long as the entire limb. The distal two-thirds is pectinated. The post-abdomen is long, slender and straight. The distal portion of its outer margin is pectinated. The terminal claws are curved and -are a little longer than half the length of the abdominal rami. ‘ ; Pik ri ay ee 326 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. | Habitat: Cincinnati, Ohio. Very abundant in a shallow canal q basin in Camp Washington. Up to date it has not been found in any other locality. re : LATE LARVAL HISTORY OF CYPRIS HERRICKI. PLATES LXVIII, Fias. 40-42; LXIX, Fies. 33-39. In this connection it is not intended to discuss the early stagesof Oypris Herricki. These remarks will be confined to what corresponds. to the seventh to ninth ecdyces of Cypria opthalmica Jurine. Not only that, but the remarks will be restricted to the external morphology. __ It is hoped to discuss the internal anatomy in a subsequent paper. % See The earliest stage here discussed has been compared to the seventh stage of Cypria opthalmica Jurine, because in thatstagetheappendages have attained about their permanent form; but it must not be sup- minal spine to the le gth of posed that in this Cypris there are only two subsequent larval ie ie beh. These stages are tabulated in the following table: y e. P $ St tle Stages.| Length. Height. Position of Dorsal Hump, Ete. Form of Post-abdomen. 1 Rudimentary; fewer spines- Bp. os A 0.90mm. | 0.57mm. | Some distance in front of middle. fea a jouer se ieee 7, ie Teeth on caudal margin of shell. than remainder of the ap- a ‘| pendage. . fr 4 4 * i i 1.32mm. | 0.71mm. | Approaching middle. ace xa elec: beer bt = Cy ee to to length of the post-abdomen. 1.38mm. | 0.84mm. | Teeth on shell much larger. greater than in adult. % 1,98 mm. | 1.20mm. | Near the middle. Ratio of the Jengtt as ; Teeth on shell large. shige ete © nearly Pag ~ |2,79mm. |1.é4mm, |Atmiddle. | © | Aboutasinadult, 1” oy v4 Teeth disappearing. ey. 2 Adult. | 3.00 mm. Atmiddla. e™ See ee ee hy an ks aE 8 Ba No teeth on shell. ¢ Pa Sea In Cypria opthalmica (Jurine) Claus found that by the time the seventh stage was reached, the shell had practically assumed its final — form. Inthe form here described there are pronounced differences. between the earliest stage here considered and the adult. In the adult of Cypris Herricki the dorsal border of the shell is. almost uniformly convex and the cephalic border of the shell is about the same height as the caudal. In stage A (Fig. 33), however, the shell is highest near the cephalic extremity, and the cephalic border of the shell is higher than the caudal. As the animal passes through stages B to D, the highest point of shell moves gradually towards the middle and the height of the caudal margin of the shell approaches. more and more the height of the cephalic margin. Sed SS £5 RY A? PO! oe Fe We ee ae Oe ats.’ SPN ir SRE See we RS VRE OS Fase Be Vg i cyan sith So oN eR ve ea a ! ENTOMOSTRACA OF MINNESOTA. o2T - In the adult Cypris Herrick the caudal margin of the shell is entire. But in stage A, the caudal margin of the shell is bordered with minute teeth (Fig. 34). In this stage the teeth are quite small and might easily be overlooked; but in stage B (Fig. 35), these teeth have become very conspicuous. Indeed, they are the characteristic feature of the shell. These teeth are present throughout stages A to D, but in stage D they have begun to disappear. In the adult stage there is no trace of these teeth. A careful study of the adult shows that the shell is covered with hairs. These hairs are very conspicuous in stage A. The shell of the adult is marked with very conspicuous dark bands. An effort has been made to discover at what period these bands appear, and to see if they conform to the rules laid down by Professor Eimer. The characteristic bands on the shell may be present in any stage from A to the adult; and when they are present they do not differ essentially from the markings on the adult. The chief points of dif- ference being variations in the width of the bands. In all examples of stages Cand D examined, these characteristic markings were found; but in stages A and B, they were occasionally absent. An examination of Fig. 35 will show that some of these bands are longitudinal while others are oblique. Professor Eimer has attempted to establish the following rule for the formation of oblique markings on animals.* Oblique markings first appear as longitudinal lines. These lines become resolved into dots, these dots, in turn, rearrange themselves in oblique lines. If these laws were applicable to the markings on Oypris Herricki, in stages A and B, where we have some specimens with bands and others without them, we ought to find some transition stages—some stages in which the oblique markings were represented either by parallel lines, or by series of dots. But such is not the case. The shell is either un- marked by bands, or both oblique and longitudinal bands are present. As stated above, in stage A the appendages have practically as- sumed their permanent form. The post-abdomen is a notable excep- tion. This appendage is quite rudimentary; not only has it not yet acquired the typical number of set#, but the longest terminal seta is as long as, or longer than, the remainder of the post-abdomen. This great relative length of the terminal seta is due, not to an over-devel- opment of the seta, but to an under-development of the body of the post-abdomen. That the post-abdomen appears to be the last append- age to development is rendered more striking by the discovery of C. Claus that the post abdomen appears before the formation of the sec- *@.H.Th. Himer. Organic Evolution as the Result of the Inheritanze of See Characters According to the Laws of Organic Growth. Translated by J. T. Cunningham, 1890. P. , Pp is < Cte +) Sib eee TOC SAN » Ch p Hae LOE SAY Basten Oo) Ab \ b ‘ : q it ee: 328 GEOL. AND NAT, HIST. SURVEY OF MINNESOTA. ond pair of legs. In stage B the post-abdomen has developed the per- manent number of set, but the ratio of the length of the terminal seta to the length of the body of the member is much greater than in the adult. In passing through stages C and D, the parts of the RO abdomen gradually assume the proportions of ahve adult. Every precaution has been taken to be sure that all the stages above described were stages of one and the same animal. . A definite number of each stage was isolated in saucers of water and a record kept of the number placed in each saucer, and also of the stage of growth exhibited by each set at time of isolation. The water used was collected from a pool which did not contain any Ostracodes which in the least resembled those under consideration. As a further pre- caution the water was allowed to stand in the laboratory a couple of weeks. The loss in volume was replaced by river water, taken from the city hydrant. I never have found any Ostracoda in said river. Thus there was no possibility of the water containing the eggs of Cypris herricki. The larval stages which were placed in this water — were examined from time to time. In every case the specimens devel oped into the adult form. The morphological differences between the shell of stage B and the Shell of stage A, and between the shell of stage B and the adult, are certainly as great as the morphological differences between the shells of closely allied species. The morphological differences between stage A and the adult are differences, not only in the shell structure, but also in the structure of the post abdomen. And these differences are aS great as those between the genus Cypris and the genus Oypri- dopsis. These facts show that shell structure of Ostracodes, when taken alone, is of almost no taxonomic value. These facts also have phylogenetic significance. These various — larval stages are resting stages in the development of Cypris herricki. Since it is true that the ontogenetic development of an individual is a rapid and compact repetition of its phylogenetic history, these larval forms must represent past stages in the evolution of Cypris herricki. As has been stated above, stage A corresponds very closely to the genus Cypridopsis. The main distinction between the genus Cypris and the genus Cypridopsis is the difference in the form of the post-abdo- men. Inthe genus Cypridopsis the body of the post-abdomen is but slightly developed, while the sete are quite long. In stage A, in the larval history of Cypris herricki the post-abdomen is in this rudiment- ary condition; thus it corresponds very closely to the genus Cypridop - sis. Not only that, but the unbanded forms of this stage correspond very closely to Cypridopsis hystrix Herrick.* Indeed, when this stage y, Bates L. Herrick. Contribution to the Fauna of the Gulf of pitts: and theSouth. 1887. P.30, Pl ig. 6 ENTOMOSTRACA OF MINNESOTA. 32D / was first encountered, it was supposed to be a Cypridopsis. While working at its anatomy a specimen with the markings characteristic of Cypris herrickt was discovered. This led to an investigation of the larval history of the crustacean. These facts give us avery strong hint that the genus Cypris has. been evolved directly from the genus Cypridopsis. Should future research show that all members of the genus Cypris have a Cypridopsis ‘stage, the discovery would give much weight to the hint. And if, at the same time, the internal structure should prove to be similar, the evidence would be conclusive. ‘ Cypris (?) albuquerquensis sp. n. PLATE LXXVIII. Length 0.5mm. Height 0.28mm. Width 0.35 mm. This is a small greenish hirsute shell about twice as long as high and much wider than high. Viewed from the side (Fig. 1) it is sub-reniform. The two extremi- ties are rounded, but the cephalic is broader than the caudal. The dorsal margin is convex, the ventral nearly straight. Viewed trom above (Fig. 2) the shell is a broad oval, widest near the middle. The cephalic extremity is a trifle narrower than the caudal. Hingeline straight. The terminal claws of the antenna are long, slender and non-pecti- nate. The natatory sete on the antepenultimate joint do not extend beyond the tip of the terminal claws. The feet are stout. For details consult Plate LX XVIII, Figs. 1-7. This species has not been encountered by the author. The descrip- tion is based on drawings furnished by Professor C. L. Herrick. Habitat: Albuquerque, New Mexico. The data at my disposal render it impossible for me to rightly classify or characterize the following species: ©. agilis Haldeman (78), C. discolor Haldeman (78), C. scabra Haldeman (78), C. simplex Hal- deman (78), C. vitrea Haldeman (78), CO. hispida De Kay (58). GENUS CYPRINOTUS Brady. 1885. This genus was first established by Professor Brady (26) in 1885 to include a peculiar form that had been discovered by Mr. A. Haly in “Ceylon. Professor Sars (195) in 1889 amended the genus in such a way as to make it include all the sexually propagated forms of the old genus Cypris. In this paper Professor Sars’ description has been P ; cs t 330 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. sufficiently modified to include the American forms that propagate sexually. It is presumed that Professor Wenzel Vavra, who objects to the genus Hrpetocypris (221), will also object to this one. The species of this group, however, are closely related both anatomically and physiologically, and it is thought that most workers will welcome the division of the old genus Cypris into the several genera here given. Shell rather thin, compressed, oval or sub-triangular, height ex- ceeding half the length, dorsal margin strongly arched, ventral almost straight. Valves usually unequal, the left valve overlapping the right. The free edges of left valve smooth, cephalic and caudal extremity usually bordered with a hyaline flange. The free cephalic end of right valve usually armed with tuberculiform teeth. Natatory sete of antennz reach beyond the tip of the terminal claw. Abdomi- nal rami are slender, with smooth or very finely pectinated claws. Propagation is sexual. Copulative organs are small, with an outer linguiform obtuse plate. The cylindrical core of Zenker’s organ bears numerous wreaths of spines. Cyprinotus incongruens Ramdobr. PLATE LXVIII, Figs. 9-16. 1808.—Cypris incongruens Ramdohr (173), p. 86; Taf. III, Figs. 1-12, 15, 16, 18-20. 1820.—Monoculus conchaceus Jurine (98), p. 171; Pl. XVII, Figs. 7-8. 1820—* * ruber Jurine (98), p. 172; Pl. XVIII, Figs. 3-4. 1820.— Hi aurantiacus Jurine (98), p. 173; Pl. XVIII, Figs. 5-12. 1821.—Cypris fusca Straus (205), p. 59; Taf. I, Figs. 1-16. 1844.— ‘‘ aqurantia Zaddach (234), p. 37. 1844.—? ‘* opthalma Koch (‘02), H. 36, p. 17. 1850.— ‘* aurantia Baird (5), p. 159; Taf. XIX, Fig. 13. 1853.— ‘‘ incongruens Lilljeborg (118), p. 119; Taf. IX, Figs. 6-7; Taf. XI, Figs. 1-4; Taf. XII, Fig. 6. 1855.— ‘* aurantia S. Fischer (65), p. 650; Pl. I, Figs. 29-31, 60, 61. 1868.— ‘‘ incongruens Brady (18), p. 73; Pl. XXIII, Figs. 16-22. | 1868.— ‘‘ fusca Fric and Nekut (70), p. 47, Fig. 28. 1872.— ‘‘ fusca Fric (69), p. 212, Fig. 26. 1889.— ‘* incongruens Brady and Norman (31), p. 73; Pl. XII, Figs. 8-9. 1891.— ‘* incongruens Wenzel Vavra (221), pp. 95-98; Figs. 32, 321-32°. 1893.— ‘‘ ineongruens C. H. Turner (213), p. 8; Pl. I, Figs. 9-16; Pl. II, Figs. 17-21. Length 1.35 mm. Height 0.75 mm. The shell is equivalve, one valve overlapping the other in front. The shell is yellowish brown in color and is covered with scattered hairs. Viewed from the side (Fig. 9) the shell is sub-reniform, widest near the middle. Both extremities rounded and of nearly the same width; the cephalic extremity may be a trifle narrower than the caudal. Ventral margin nearly straight, other margins convex. “ph SNR aera NC ai Salo a ee is c et, - \ bd Vy oe yer F ua ath bs: 4 ENTOMOSTRACA OF MINNESOTA. 331 Viewed from above (Fig. 10) the shell is ovoid, pointed in frout and rounded behind. The greatest width is caudad of the middle. Hingeline straight. Viewed from below (Fig. 11) the contact line is straight. The claws on the antenna (Fig. 13) are toothed. The plumose natatory setz reach to the extremity of the terminal claws. No dagger-shaped seta visible on either the penultimate or ante- penultimate joint of the mandibular palp. The biarticulate claws on the first mandibular process of the first maxilla toothed. The claw of the first foot is long, slender, finely pectinated and curved. The abdominal ramus is short, feeble and slightly curved. The terminal claw is long, slender, slightly curved, pectinated near the end. The claw is about two-thirds as long as the entire ramus. I have never encountered any males of this species; but since Wen- zel Vavra (221) has found males of this species in Bohemia, and since it is anatomically closely related to the other members of this group, I include it in this genus. Habitat: Rare. Cincinnati, Ohio (Turner, 213). Cyprinotus crena Turner. PLATES LXVII, Fies. 11-13; LXIX, Fies. 22-31. 1892.—Cypris sp. (?) C. H. Turner (212). p. 71; Pl. II, Figs 11-13. 1893.— ‘‘ crenata C. H. Turner (213), p. 9; Pl. II, Figs. 22-32. Length of female 1.23 mm. Height 0.63 mm. Width 0.60 mm. Length of male 1.14 mm. Height 0.60 mm. Width 0.45 mm. The shell is equivalve, very thin, the free margins of one valve are bordered with blunt teeth. The ventral margins of both valves bear hairs. Shell reticulated with contorted lines; the reticulations are most distinct on the cephalic portion of valve. Lucid spots about nine, sub-central. Color, various shades of greenish yellow. The caudal half of shell of male appears to be marked with concentric retort Shaped lines. Since the shell is very thin this appearance is due to the presence of spermatozoa or spermatophores within the shell. Viewed from the side (Fig. 22) the shell is sub-reniform, highest about the middle, cephalic and caudal extremities about the same width. Caudal, dorsal, and cephalic margins convex; ventral margin nearly straight, slightly convex at the middle. Viewed from above (Fig. 23) the shell is sub-oval, widest behind the middle. Caudal margin rounded, cephalic margin bluntly pointed. Hingeline sinuate. de | « ee 332 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. . Viewed from below (Fig. 24) same as when viewed from above. | Line of contact of valves sinuate. ae Viewed from end (Fig. 25) shell is oval, a little higher than wide. ¢ Antennules (Fig. 25) and antenne as usual in genus Cypris. Ee: The mandible (Fig. 26) terminates in four large teeth; between each 336 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. cot d i) GENUS DARWINULA Brady and Robertson. 1870. ‘Shell smooth, thin, and fragile. Carapace oblong, higher behind than in front; lucid spots ten to twelve in number, linear-oblong or — wedge-shaped, arranged in a subradiate manner in front of the centre of the valve. Seen from the side, compressed, oblong, sub ovate. Seen from above, ovate, acuminate in front, obtusely rounded behind. Valves unequal, the right much larger than the left. Antennules very short, six-jointed, and stout, strongly armed with short and stout curved sete. Antenne four-jointed, and bearing four or five strong terminal claws; entirely destitute of poison gland or urticating sete, the place of which is occupied by a single curved seta of moderate length. Mandible broad, truncated at the distal extremity, which is provided with six or seven small spiniform teeth; palp three jointed, its basal joint very wide and fringed with several curved sete, bearing also a small lamina, fringed with branchial filaments; second joint long, slender, and bs is four times as long as broad, slightly curved and dilated at the distal extremity, where it bears one long and two small sete; terminal joint more slender, about two-thirds of the length of the foregoing, and bearing at the truncate apex about six slender curved spines. First maxilla divided into four short setiferous seg- ments, and bearing a very long oblong palp, which is fringed with about twenty-four long branchial filaments, and has also four other long setze at its base. Second maxilla simple, short, and broad, trun- cate at the apex, and fringed on the distal margin with several slender spine-like hairs, bearing also a large, three-jointed, pediform palp, and an ovate branchial appendage of moderate size. Two pairs of feet of moderate size, five-jointed; second pair much the longest, and hay- ing the last joint armed with one long and two small curved sete; first three joints of nearly equal length; fourth and fifth, respectively, about one-half and one third as long as the preceding. Abdomen ending in a short conical process. Copulative organs of the male of complex structure, the basal portion of an irregularly-shaped plate produced laterally into an aliform process, and on the distal margin into a short, strong hook. Female probably viviparous.’’ (Brady and Norman, 31.) Darwinula improvisa sp. n. PLATE LXXXI, Fias. 1-3, 13. Length of female 0.68 mm. Height 0.27 mm. Width 0.24 mm. Length of male 0.70 mm. Height 0.23 mm. The right valve is larger than the left and overlaps it on the ven- tral side. In the female the height is more than one-third of the Ses ae pea © Fas ba reas Pa eer oe Pe yee ~ ies rea tele Pp: ENTOMOSTRACA OF MINNESOTA. 337 length and the width is less than the height. In the male the height is about one-third of the length. The color is yellow, with two green blotches, one on each side, in front of the middle. These patches of pigment are on the animal but show conspicuously through the trans- lucent valves. The female carries her young in the enlarged caudal portion of the valves. These are white and show distinctly through the valves. Viewed from the side the shell is oblong, depressed in front, broad- est caudad of the middle. The two extremities are rounded, the cephalic end is narrow, while the caudal one is broad. Viewed from above the shell is ovate-acuminate, widest near the caudal extremity. The cephalic extremity is pointed while the caudal is broad and notched where the two unequal valves meet. The antennules are stout and appear to be composed of only five joints. In this respect as well as in the arrangement of the sete this member differs from the corresponding member of D. stevensoni. The antenne are stout and are composed of five joints. The long terminal claws are as long as the combined lengths of the last three joints. The antepenultimate joint bears a conspicuous one-jointed appendage which terminates in one long and one short filament. Here we have another marked difference between this species and D. stevenson. The mandible bears a three-jointed palp, to the termiral joint of which is appended a lamina bearing several long curved filaments. The second maxilla bears a leg-like palp. The first foot is stout and five-jointed. Thesecond foot is not bordered by a fringe of hairs, For arrangement of the sete consult the figures. The second foot consists of five joints; the terminal claw is longer than that of the first foot. Like the first foot, none of its members are bordered with short hairs. For the arrangement of set consult the figures. The abdomen terminates in a pointed process. Habitat: The only specimens yet found were collected in a sand bottom reservoir at Atlanta, Georgia, Sept. 1, 1894. This reservoir is about three miles in circumference and is fed by creeks which arise a short distance off at the watershed of the state. AG arg ees peice lead eae ae SE NERA ay SNS CaN en ai eae CO RS Aes + Sa, a fs 7: ine, SV a se 7 i" hy i Koa PLATES AND Pea NATIONS \ _ EXPLANATION OF PLATE I. 10. One of the swimming feet. Limnocalanus macrurus Sars. \ 1. Left foot of the fifth pair in the male. 2. Right foot of the same pair. 3. Foot of the fifth pair in the female. 4. Abdomen. — : Eurytemora affinis Poppe. 5. Female from above. 6. Right antenna. 7. Fifth foot of female. 8. Feet of fifth pair in the male. 9. First foot. Pseudodiaptomus pelagicus Herrick. 11. Lateral view of female with ovisac and spermatophore. | 12. Fifth feet of female. 13. Fifth feet of male. 14. Portion of right male antenna. ee gibber Poppe. Fifth foot of male. roubaui Richard. Fifth foot of male. salinus Daday. Fifth foot of male. wierzejskii Richard. Fifth foot of male. richardi Schmeil. Fifth foot of male. incongruens Poppe. Fifth foot of male. lobatus Lilljeborg. Fifth foot of male. mirus Lilljeborg. Fifth foot of male. minutus Lilljeborg. Fifth foot of male. siciloides Lilljeborg. Fifth foot of male. theeli Lilljeborg. Fifth foot of male. franciscanus Lilljeborg. Fifth foot of male. signicaudatus Lilljeborg. Fifth foot of male. serricornis Lilljeborg. Fifth foot of male. laciniatus Lilljeborg. Fifth foot of male. franciscanus Lilljeborg. Antepenultimate joint of right male antenna. trybomi Lilljeborg. Antepenultimate joint of right male antenna. PLATE VIII. ZooL. SURVEY OF Minn., II, 1895. Ss tS ry ONS Peake Te Diaptomus ee 66 gracilis Sars. Fifth foot of male. amblyodon Marenzeller. Fifth foot of male. oregonensis Lilljeborg. Fifth foot of male. trybomi Lilljeborg. Fift foot of male. castor Jurine. Fifth foot of male. lilljeborgi De Guerne and Richard. Fifth foot of male. coeruleus Fischer. Fifth foot of male. glacialis Lilljeborg. Fifth foot of male. leptopus Forbes. Fifth foot of male. Signicaudatus Lilljeborg. Abdomen. roubaui Richard. Abdomen. serricornis Lilljeborg. Antepenult joint of right male antenna. | wierzejskii Richard. Antepenult joint of right male antenna. | | ZooL. SURVEY OF Minvn., II, 1895. PEA Eee EXPLANATION OF PLATE X. Fie. ie 2. 3. 4, B. 6. 7. 8. 9. 14. 15. Diaptomus lumholtzi Sars. Fifth foot of male. 6é 66 baccillifer Koebel. Fiftii foot of male. pectinicornis Wierzejski. Fifth foot of male. denticornis Wierzejski. Fifth foot of male. orientalis Brady. Fifth foot of male. zachariasi Poppe. Fifth foot of male. asiaticus Uljanin. Fifth foot of male. tatricus Wierzejski. Fifth foot of male. tyrrelli Poppe. Fifth foot of male. affinis Uljanin. Fifth foot of male. eiseni Lilljeborg. Fifth foot of male. laciniatus Lilljeborg. Abdomen. trybomi Lilljeborg. Abdomen. Heterocope saliens Lilljeborg. Fifth foot of male. 66 borealis Fischer. Fifth foot of male. 16. Broteas falcifer Loven. Third maxilliped. PLATE X. F Minn., II, 1895. ZOOL. SURVEY O m+ ees Te EXPLANATION OF PLATE XI. , pischura neyadensis Lilljeborg. Fifth feet of male. es nordenskiceldi Lilljeborg. Fifth feet of male. Heterocope appendiculata Sars. Fifth feet of male. Epischura nevadensis var. columbize Forbes. Fifth feet of male. a nordenskieeldi Lilljeborg. Abdomen. . nevadensis Lilljeborg. Abdomen. columbiz Forbes. Abdomen. = nevadensis Lilljeborg. Fifth foot of female. e nordenskiceldi Lilljeborg. Fifth foot of female. - nevadensis var. columbiwe Forbes. Fifth foot of female. Poppella guernei Richard. Fifth feet of male. Eurytemora velox Lilljeborg. Fifth feet of male. Beckella brasiliensis Lubbock. Right fifth foot of male. 5 triarticulata Lubbock. Right fifth foot of male. Centropages brevicaudatus Brady. Abdomen. as brevicaudatus Brady. Fifth feet of female. - ZOOL. SURVEY OF MInN., II, 1895. PLATE XI. i y ‘ x ‘ EXPLANATION OF PLATE XII. Osphranticum labronectum (Potamoichetor). - . , Male. Antennule. . ; Maxilliped. Fifth feet of the male. 7 re Palp of the mandible. ie End of the abdomen. Feet of the first pair. Kye. Cyclops ater. Female. Abdomen. Maxilliped. Antenna. Osphranticum labronectum. Maxilla. si, labronectum. Antenna. ZooL. SURVEY OF Minn., II, 1895. PRAT Xhk ‘EXPLANATION OF PLATE XIII. 4 ty SNES Alonella pulchella. Female. Reticulations. Post-abdomen. Alona modesta. Male. Diaptomus similis. Female . Jaw. Fifth foot of the male. Fifth foot of the female. Diaptomus minnetonka, Fifth foot of the male. Fifth foot of the female. Abdomen of the female. Diaptomus stagnalis. Margin of the last thoracic segment. a Sanguineus. Margin of the last thoracic segment. a stagnalis. Fifth foot of the male. Epischura fluviatilis. Abdomen of the male. me lacustris. .Fifth feet of the male. is fluviatilis. Fifth feet of the male. Diaptomus pallidus. Inner ramus of the fifth feet of the male. ag sicilis. Inner ramus of the fifth feet of the male. ZooL. SURVEY OF Minn., II, 1895. RIGA Gombe EXPLANATION OF PLATE XIV. . 14 tae ae *~ , ci i. oe ee Hie ny a, bt fe) & Female from above. Antenna and antennule. Foot of the first pair. Foot of the third pair. Foot of the fourth pair. Caudal stylet. Fifth foot. Sixth foot of the male. Antenna of the male. See, ee COND HW Specimens from Albuquerque, New Mexico. Cyclops viridis var. americanus Marsh. _ PEATE <1Ve Zoot. SurRveEY oF Minn., II, 1895. ae Ss \\ ae ‘: oy \ Pe JSS crete eS = ~N + gael! ey) < Be i=) ) Lol e oe oo bo ADs Cyclops phaleratus. | Outline of the male from above. Stylet of the male. Fifth and sixth feet of the inal Antenna of the male. Antenna of the female. Fifth foot of the female. Fourth foot. Cyclops fimbriatus. Stylet. Antenna of the female. ‘ Cyclops languidus. Antenna of the female. Fifth foot. BUAT Evil: Tis 8805. ZooL. SURVEY OF MINN., re 4 pea es ‘ ¥ Few ol ax r, E 4 Sin? * _ EXPLANATION OF PLATE XVIH. ¥ ey je Sar ‘ ey , ve SE ae - _ ee, Cyclops leuckarti. Slender form. Abdomen. Labrum. Antenna. Fifth foot. Feet of fourth pair. . (\s Feet of second pair. Feet of first pair. Antennule. Maxilliped. Mandible. P Cyclops phaleratus. | Ventral view of female. Part of the abdomen of the male with sixth foot. Antenna. Labrum. Pair of feet. Cyclops bicolor. Lateral view. Abdomen. Foot of the fourth pair. Antenna. Labrum. : Receptaculum. ZOOL. SURVEY OF Minn., II, 1895. PEATE XViit. | EXPLANATION OF PLATE Oo OAD Male. Under surface of abdomen. ; “feb eas Last joints of antenna of the female. roe The spine of the distal segment of outer ramu incorrectly shown as curved. _ . First foot. Fourth foot. Stylets. Fifth foot. Antenna. Abdomen. Fifth foot. Stylets. Antenna. Cyclops phaleratus. Female. Cyclops serrulatus. | | ie "ite, — Cyclops diaphanus. Cyclops gracilis, Cyclops varicans. PLATE XIX. Zoot. SuRvVEY OF Minn., II, 1895. ; EXPLANATION OF PLATE XX. We * ee i ue Z lost — AIS ee = _— = Fe AE “Se > 12. 13. 14. 15. 16. AT. 18. aD: 20. 21. - Cyclops signatus var. tenuicornis. Female. Mandible. Maxille. Stylet. Fifth foot. Maxillipedes. Antenna. Cyclops signatus. Abdomen. Antenna. Fifth foot. Male antenna. Cyclops parcus. Abdomen. Antenna. Fifth foot. Receptaculum seminis. Cyclops adolescens Abdomen. Foot. Antenna of female. Kye. Antenna of male. Cyclops signatus. End of antenna. PLATE XX. II, 1895. ZOOL. SURVEY OF MINN., at aie aE S ; mu Ki o iin e | EXPLANATION OF PLATE XX1. ry Side wee perce 16. V7. 18. 19. 20-21. 22. 23. Cyclops modestus. Side view. End of the abdomen. Outer ramus of first foot. Outer ramus of second foot. Fifth foot. Cyclops phaleratus. Fourth foot. Outer ramus of first foot. Fifth foot. Caudal stylets. Antenna of young, otherwise perfect. Cyclops fimbriatus. End of abdomen. < bicolor. Abdomen. Cyclops ater. Inner ramus of first foot. Outer ramus of first foot. Outer ramus of fourth foot. Cylons signatus. Fourth foot. ater. Inner ramus of fourth foot. a ater. Stylet. ‘ sp.2 First foot. ‘¢ gp.2 Terminal segments of fourth foot. parcus. Fifth foot. Chydorus globosus. First foot of male. PLATE XXI. ZooL. SURVEY OF Minv., II, 1895. LE AES. See A EEE afta EES eo ae KL ——_—<———— ~ = tk: ae EXPLANATION OF PLATE XXII Canthocamptus minnesotensis. ‘ag 1. First foot. | | a 2 2. Stylets. fas b fins» tim 3. Antenna of female. ae eo 4. Fifth foot of female. . sa ae 5. Fifth foot of male. . Sea BS: fi 6. Antenna of male. . to, Raa St 7. Daphnia hyalina (D. galeata). Young. Bt 8. Re 5s xe - Male. . 9: Camptocereus leucocephalus. Male. Pia Ae 10. Alonella excisa. Male. me eae ae : Cyclops insignis. in 5 i oY 11. Outer ramus of the first foot. is? «12, Fifth foot. ‘eg 13. Fourth foot. + 14. Stylet. i 15. Worm parasitic in arterial sinus of Daphnia schaefferi. : Be q \ # Bi 4 Rei i ay a aay 4. ie Ce ie oe : PLATE: XXII. Zoot. SURVEY OF Minn., II, 1895. SSS SES SS a PN mye A BAY ay aN Ay ¥ YAN oa 4, ; “ ie ! ff j ‘ ' ue ee : "7 jan , : ay PL PLPD DDD TPO d SSS SS POD Pe SS aoa > 10) he : Xe ae 5 é. ‘i r) ih t! Cyclops ingems. ve Apea ewe at, nt ae mary aN t u . a re on First segment of abdomen of ferpalee ess aks co vote Antenna. | Se yah Ae a ay . s een Oy Rie, Farge oe peter Fifth foot. ere eee Se Sere «“ ¥ Nar hee ao A Antenna of young male. — onan? aah he eats Stylets of mature female. Att BRIA } ee " Mi Stylets of young male. a a aoe Ste Maxilliped. Peay i ae “OSes Said Mandible. Ben? Goes he AIRE SUN RG eed if be > . \ Cyclops fimbriatus. 7 “ Female from above. . Antenna. ergy MMe eat RUA ae hE Terminal portion of abdomen. . Le Rasa Female fifth foot. Teather Second antenna. Nauplius form. PLATE XXV. ZOOL. SuRVEY OF MINN., IJ, 1895. ~ » m EXPLANATION OF PLATE XXXVI Female from above. b crhaaee Antenna. 1 6 ea ‘ Antenna of young. ee es. Abdomen of young. eh ae Foot of young. i Foot of adult. Fifth foot. Eye. (Should have been cut out.) a Cyclops serrulatus. Young from above. Daphnella brachyura. : Female. Lateral view. eke! Male. a fp Edge of valves. Abdomen of male. Abdomen of female. 2 ; Antenna of male. A i Cyclops fluviatili Men PLATE XXVI. ZooL. SURVEY OF MInn., II, 1895. vt EXPL ANA’ TON GSK 33" Fic. ; Neng oy ee eee 1. Of moderate size. 26g posi Se - 2. Antennule of male. f a Sbyekat pel Fee 3. Head of variety. SS As (0 Ra ts Seo Maga 4. Cyclops pulchellus (thomasi). Fourth foot. 2 2 5. « — pulchellns (thomasi). Outer ramus of first foot. 6, Daphnia hyalina (D. galeata). Typical form. nee 7. Cyclops thomasi. Fifth foo . Ht Sa ane te 8. “« thomasi. Stylet. . vat ae 9. Cyclops (insectus?). Fourth foot. tn ee 10. Bythotrephes longimanus. Female. S45: Os a ae 1i. A curious large protozoan; a. infundibulum frame work ; pulsating vacuole; c. nucleus; d. food and digested matt er ; e. xt protective rods; ae spicules of the infundibulum. ast be ay \ \ | t - sib, Sa oat 7 = eat Clie Wh v Eee a ee - i * ‘ » 72GB es 62! . j ale ? sent = aie PLATE XXVII. Zoou. SURVEY oF Minvn., II, 1895. Meu, > ie i i , ef 1+ Nie “— ts ,} . a hy a t . wa “ , * Soa Cyclops capittiferus Forbes; ee Fic. Ai feiss Sota ents 1. Female. mae Sue —s 2. Leg of the fourth pair. he terminal spine of the o Batra? St is represented too broad. eens as i ss Bs Leg of first pair. | sae ata . 4, Fifth foot. iS eae 5 Fae "A Leg wf first patty. cet ed Leg of second pair. ~ Rate Leg of fourth pair. erst ca Fifth foot. ae All the figures are copied from Forbes. - =. £ CID Ot Zoot. SURVEY OF Minn., II, 1895. PLATE XXVIII. > ar dy ; rene ¥ Nagao" Sven < re \ Sade Pa SS, ay PN ree ie <4 : YS i . | re) ? ON OF PLATE XXIX, — i. ; : ie AS ge apo a Canthocamptus illinoisensis, ‘ “ Fic. ; ; ‘ ' A oe bp ee oh z 1. Antenna of female. SRS SE) De repre Lan aes : sf 2. Fifth foot of female. — | Be Phat e t Rne e teem Lyi 3. Antennule. ~ Sica NaN ee he te te z 4. First foot. Ee eae REEL Sah ys. 5. Caudal stylet. ~ Rare ce been gi i ce oa Canthocamptus northumbricus var. americanus. 7 e 6. Fifth foot of female. aa 7. Antenna of female. in eee. 8. > Maxtiliped. Reese yt 9. Caudal stylet. ‘i oe 10. Antenna of maie. ’ ane Ti ite i 145° First foot. ol aah egeer vce © ae 2 ames Beh Li) HOUnt toes, poets ee A ee tae ede oh ie 13. Fifth foot of male. ee en fsa Boe i4. Frontal area. cts en ae 15. Canthocamptus tenuicaudis. Stylets. Res 16. - ~ tenuicaudis. Fifth foot of female. - : \ " é b ae ie: Cyclops serrulatus. ese Be". 17, Fifth foot. Sah 18. Fourth foot. 19. Outer ramus of first foot. : Canthocamptus northumbricus. 20. Inner ramus of third male foot. saat 21. Beak. = 4 22. Maxilla. PLATE XXIX. ZooL. SURVEY OF Minn., II, 1895. * od Re Ria ok TE * ‘ neh Mae \<9 , oe Choe weal Vie x ant 1 Syerehen y oi See Lar $ Py Pm tie ng ty ageing 1a ether ARS | | eh eae jae ¥ i . \% Se Tay ae . Immature female. — = a, d - ae Gyetond’ varicans Bate ‘aa teed : * i Se, Ae a8 9, Female from above. 38. Caudal stylets. _ 4, Antenna of female. 5. Maxillipedes. 6. Feet of first pair. 7. - Feet of fourth pair. 8. Fifth foot. Cyclops ‘genie. Sars, 9. Caudal stylets, after Schmeil. 10. Receptaculum. 11. Fifth foot. PLATE. XXX ZOOL. SURVEY OF Minn., II, 1895. Ler! + _ th i Ne Pen Sak Si) ha Ey gt PH RPO SERS NOD ASEAN Hy | ED Naa oti 125 et ae babi a Saletan rea i , a ‘ + ms Ay Vide Sire res an ; SRE AC, SO 7 P) “eer -. oe, t Antenna of se _Antennule. Rome cee tk SN Ta End of mandible. | . = Nee of Anterior maxilliped. nt a ea Posterior maxilliped. prea c eig Sree Caudal stylet of female. . Os Pay tat PUES ee First foot of female. Saad i Outer ramus of second foot. pao ge res Third foot. . het Shite A Fourth foot. pr he Sea Fifth foot, (a) variety, (b) type. sty Caudal stylet of male. The union of the two setee is import figured. They form a U-shaped sumone union. Be . ie - 2 PEATE XXXI. ZOOL. SURVEY OF Minn., II, 1895. oe; ; : t 4 J 1 _ EXPLANATION OF PLATE XXXII. ‘ Marshia albuquerquensis. Fig, 1. Antenna of male. 2. Antennule. 3. Fifth foot of male. 4, Fourth foot of male. 5. First foot of male. Marshia brevicaudata Herrick. 6. Male. 7. Caudal stylet of male 8. Fifth foot of male. 9. Fifth foot of female. 10. Antenna of female. 11. Posterior maxilliped. 12. Antenna of male. 13. Second foot. Zoou. SURVEY oF Minvy., II, 1895. PEATESX xox, hh et iy Cyclops signatus var.* tenuicornis. Caudal stylet. where the inner aspect is ciliate. Fourth foot of same. Canthocamptus northumbricus var. americanus. Caudal stylet. Maxilliped. Fifth foot. Diaptomus hircus. Left fifth foot of male. Right fifth foot of male. Fifth foot of female. / Diaptomus sancti-patricii. Fifth foot of male. Fifth foot of female. Appendages of penultimate joint of right male antenna. Figs. 6-11 are after Brady. ZOOL. SURVEY OF Minn., II, 1895. PLATE XXXIII. Se SS SS att ? Jim aa ie a. a) er EXPLANATION OF PLATE XXXIV. acter Cyclops parcus Herrick. Camera pinnae vi) female, elongate form. 3 2. Antenna of female. The relative length of the sete of h joint is not quite accurately figured. te Caudal stylet of elongate form. Receptaculum seminis. Fifth foot. Foot of first pair. Foot of second pair. Foot of fourth pair. PLATE XXXIV. Zoot. SURVEY OF MInwn., II, 1895. tee Yann eZ Vl lis 1p Llltll Lie +, EXPLANATION OF PLATE XXXV. Daphnia pulex var. nasutus. ‘¢ similis. Outline of head and (a) beak. Leptodora hyalina. Seen from above. vf hyalina. Larva. Latona setifera. Female. Limnosida frontosa. Female. ; Seay ms frontosa. Antennule of male. Holopedium gibberum. Female. Sida elongata. Head outline. ‘‘ erystallina. Head outline of young female. “ erystallina. Antennule of male. ‘ erystallina. Antennule of female. — = hyalina) “D. galeata.” Outline of head. he “DD. vitrea.” Outline of head. ZooL. SURVEY OF Minn., II, 1895. PLATE XXXV. oy Py Cpe eee 4 BI NAA Ah Ne 45 i XXXV EB Mf 2 OF PLAT y 1 . ION Ai al coe ANAT Ras tae Fie. 5 ~Maxilla. Alona sp.? Pseudosida tridentata. Female from above. — | . ‘ Antennule of female. End of post-abdomen. First foot. ie. Moinadaphnia alabamensis. Bis Post-abdomen. Antenna. Female viewed from side. Antennule. One of the feet of Pseudosida. ATE XXXVI. =f PI ZOOL. SURVEY OF Minn., II, 1895. _ EXPLANATION OF PLATE XXXVIL. a4 - ¢ HAY Bes) 0 ery wry Sida crystallina, i ete, Be ates Sehr see ee _. 1. Female. . . Pik eae oh ee 2. First foot. RS oun ere of Daphnella brandtiana. 88 by ‘ 7 f Sy: od 7 es ¥& ' . Side view. ‘ EL, wis Dy ere. ae 3 4. Antennule. Raa Rte | 5. Inferior angle of shell. ¢ Wo _ 6. Claw of post-abdomen. PLATE OSX VI. 1895. ZOOL. SURVEY OF Minn., II, \ Y, SS S ELIE RS en ae pe Sry ae Pets" METAS Ie, [ON OF PLATE XXXVI. Latonopsis occidentalis 1. Female from above. = ‘ 2 as 2. Ephippial (?) female from the side. = ae 3. Ordinary female from the side. ; es 4. Antenne with usual armature. aie © Ey. ‘ 6 . Inferior angle of shell. . Antennule. PLATE XXXVILII. i ar oos: ZooL. SURVEY OF MINN., iM he ay fans % . Moina rectirostris Mueller. : Fie. $3 Se tae Pet ni, ; 1. Female with summer ova. EE ke aan pax 2. Portion of the shell near the postero-inferior angle. _ 3 . Post-abdomen. Se ea 4. Antennule. — Moina brachiata Jurine. 5. Female with summer ova. , 6. Antennule. The lateral flagellum is omitted. 7. Post-abdomen. | ge 8. First foot of female. 9. Moina paradoxa Weismann. Ordinary form. IG Se Oe gh dP Oa Oo ke era EE ie ae + ited or is ZooL. SURVEY oF Miwvn., II, 1895. PAT Oe de 3 bi Ae sos oe aan erect i Said yi at ary tee va wie we ¥ “ i 4 Ue Pals beret = F Y awe i x3 ya * = rf 1 hn Ver ete w% 4h Far) (ER SS . Tage Ne ‘ oe eoeseey ey) ORE ATTA EEF ‘ Pp ae Sie s Bee CesT GM Neate Jasa ‘ 4 9 srt ie Bas ae OF PLA ee 8 aete yeas ee Pere) yy de we - Moina paradoxa Weismann. pagal femiile with ephippium. — Antenne omitted. : se Male, from the side. } Ri “hy Adult female with summer eggs, Soom hou below. < View of the head, from the side. St, stomach; cw, coecum Br, brain; anl, antennule; J, flagellum of same; 2, Te cesophagus; ey, eye; da mandible. First foot of male. Rat Antennule of male. ~~ First foot of female. — . All the figures are camera drawin gs from New Mexican sp 7001.. SURVEY oF Minn., II, 1898. PLATE XL. SSEESsy Ht » Bho, wi ma ne Crane ’ MAN verily iy) y $ : Y TION OF PLATE XLI. ; Fic. 1. Moina paradoxa. Abdomen of female from Minnesota. ar ee * Spine from post-abdomen. : 2. * — rectirostris. Post-abdomen. bi) apa 3. ‘* paradoxa. Head of female, showing: (a) eye with pigment _ Es and lenses, (b) supra-cesophageal ganglion, antennule | - with (c) its muscles, (d) itsnerve, and (e) its terminal yan sensory filaments, (f) the cecum of stomach, (Gi ee optic ganglion, (h) stomach, (7) cwsophagus, es the oS muscles which move the eye, also part of the jabea f 4. ** paradoxa. Antenne. eee 5. * — rectirostris. Ephippium. ets! eee 6. “© paradoxa. Ephippium. ; roi eee v¢ at “ Seminal cell. | é : sant Ware st A group of seminal cells less magnified. &. * _ rectirostris. Seminal e¢ells. Ha 9. * paradoxa. First foot of male. Sarees 10. * yeetirostris. First foot of male. (From Weismann). Lk. $$ te Male. (From Weismann). 12. Ceriodaphnia rotunda. Head. ; 13. * punctata. i 14. Mf pulchella. =“ Me 15, cs reticulata. — ‘‘ ; 16. ee quadrangula. ‘ 17: ph “3 “¢ (Variety. ) 18. st . Post-abdomen. | So eee 19. é _pulchella. i ; Naan 20. cs megops. Si ; Raa D1 ¢ reticulata. 2 ferns 22. ‘ laticaudata. ig 23. : rotunda. + ‘ie Figures 12-23 are after P. E. Mueller.) ee i Rs: Pe Zoot. SURVEY OF Minun., II, 1895. PLATE XL) ai es Aaa ta Ceriodaphnia rotunda. Male (after Kurz). Ra ae Sr. alabamensis. Female. sous Ce ee “ veticulata. Post-abdomen of 1 aise with oe line vas deferens (after Weianen) a fs ‘pomsbrs? 5.848 pease aca had poe Ceriodaphnia scitula. — ~~ Head of female. f Pa RES a oa Post-abdomen. Eee ee tae Antennule of male. ene ait | inte ae _ . Semeri cells of wale.icj sate ta ae veen, Niger ot ea Scapholeberis aieyitans Adult female. pas eea ai Sd ia angulata. First foot. Be nce eae ee armata. Adult female. eat ie ae ‘ a 3 armata. From below. - Ofryoxus gracilis. Young. Labrum. Antennule. . ; m Wi Aspe ee Last foot. Purple pigment in lower part. ZOOL. SURVEY OF Minn., II, 1895. Pin hE ocb he: Sonatas IRCA RR ME Ab’ Tania Ba eich ae Le Ndsite ‘ i : a ia ean Moina brachiata. | +} Leg of fifth pair, after Lund. beg of third padre.) Vein. ened Ceriodaphnia reticulata. Leg of fifth pair. be Sere - Scapholeberis mucronata. Post-abdomen. Foot of second pair. Foot of fourth pair. Female, seer from above. 7 \ PPA Ey OI. Zoot. Survey or Minn., II, 1895. N 22 : S Sey Tt Sens ree SS ej n \y Ce css mm. . x wey } > o -f 3 . PoE Pare tt tsa ene .¢ woe ’ c = 4 ivae AP7 neve f , zt ia pte pf t3 é if ai { cal 4 J Ceriodaphnia scitula (small tens Ephippial female. 2. Bosmina longirostris. — bie co aac 2 ue ‘“ lilljeborgii. After P. E. matin Oe [ene 4, ‘« _ Hook on the first foot of Maples oF eet epee 5. Scapoleberis mucronata. Se eh 6. ‘* cornuta. Head. oa 7. ‘© angulata. Head. = ee 7a. ‘‘ angulata. Angle of shell. eas Sh, a 8. Pleuroxus denticulatus. Male. eae _6, sLower posterior angle of shel neg t j a Buryeerens Jamellatus. 7 : { . i’ A s . te 3 ss 7. First foot. Pa Sat ae oe tet ats haan eee i: a3 : 8. Caudal claws. * , % atolls 228 og St See: ae i a > - <= SF 37 a ow Pape Bae b Df oa Werk a ' tree biked te ~ =e ~ 4 <“™ ZOOL. SURVEY OF Minn., II, 1895. PLATE XLVI. & fi , Snirah a: Merete ry ae se CROEG Wit ~ a r \ en reg? of yy Pe NS PAY Pare Ns rT Pate © “fe Gy? +5 (Wileg eae 3 rey pow ee 3 TENANT IRS FG9 ele Me ea x Ea te t 4 NY ir Si. ay" ASG, ¥ 3 * Ry sia poche " ae =<" Re UN Diaptomus pueeHiseinpienet Marsh. Fifth foot of male. 2. Abdomen of female. . Me ey 4. Fifth foot of female. Diaptomus birgei Marsh. ey betas | 4. Fifth foot of male. | NS A cen) ee cr 5. Fifth foot of female. ; 6. Terminal joints of male antenna. Canthocamptus minutus. 7. Lateral view of male. [‘‘a, testis; d, caphalie Rorie ae CG, ioe Ss sinus or dorsal vessel surrounding the intestine; d, anus; Gon A i | -csophagus; f, frontal : SenSOEY plate.’’ ] - i 8. Caudal stylet. : fa _ 9. Antenna of male. 1 tones 10. Antennule. . 11. Foot of first pair. i 12. Foot of second pair. Seine 13. Foot of third pair. a Be 14. Foot of fourth pair. ic ee neg 15. First maxilliped. a ag as - 16. Mandible. | aes «17. Spermatophore. . sia ae 18. Foot of third pair of male. ie ¢ 19. Foot of fifth pair of male. mare a : i. 20. Foot of fifth pair of female. ha z 21. Maxilla. : aa M "ata 3 | hae ae - ey o ES ee) ; SNe) S PEATE: XEVIT, Ni (thea ei Zoou. SURVEY or MunNN., A ad tan era , ‘ Ae Phyllopod Larve. HF oa as ert = Pao Reeder Lhe Sept 1, Larva of Limnetes 0.33 mm. long. AL, first antenna; A . ming antenna; Md, pupnetgrn palp; a hog * lens; m, muscles of rectum, pS naY ay e eee pte we ; ( } ; i fe pi : Lint =, sf Larva of Chirocephalus. ; 3 2. Vite from below. : MEPL S hee Ce ele ‘ 3. Caudal stylet. SEES GAC ea 4. Head, showing organs of one side. D, liver. ei ‘ 5. Muscles of swimming antenne. — ~ 6 Maxilla. a ay ay | 7. End of abdomen of an side individual. ye ak deo AS ' 8. Mandible and palpus () in this stage. ne Hee 9. Antenna of female. $ Ae 10. Antenna of male. p, inner ramus; g, frontal organ. ay dee 11. Part of Limnetes older than Fig. 1. La Pinca my 12. First abdominal segment of female seen. from below. “This plat i Re illustrates the relation between the Phyllopoda and the Cladocera on one hand (Limnetes) and the lace cts on the other eaogie: oS cephalus). PLATE XLVIII. II, 189s. ZOOL. SURVEY OF MINN., ain oe bil re Feb, cat 2. tea 6 px 8. 4 ' b 4 , ’ P Hl m oY fe . ‘ t > iMeiah ss. BGs 2a. Post-abdomen. Na dey ee ehaha. Young female. ; ese Head of female. sient sa 5 ~ j Ps hy) it * ! ‘ - nF HE) ~ Daphnia hyalina. Young female... i 553) eka | Young. Be tie coer Post-imago. — ‘ead > - Daphnia dubia, Young. ie Older female. ° . 4 « j 7 ; ; tx eon Ae ‘ st srs te é -” 7 aia eye ne fe ZooL. SuRveY oF Minn., II, 1895. PLATE XLIX. ae ae RE SR ‘ah tthe a qt ie es eee ey: eet Eye See pG Le te ax . - > < nat Ris ryveh waa “—. oe \TION 0: eA BAGS 47 in SS J Sy PASH IRSA. As Seay Mt eee ire ' Fie. a / ¢ Se oa arte 1. Daphnia Tidnnehaha: ‘Male. 1 ee oe) hee — minnehaha. Part of feet of first and second | pair. 8. Canthocamptus hibernicus. Antenna of female. — See 4. fe hibernicus. Fifth foot of female. ree Aa wig «palustris. Antenna of male. s ry ae ie 6. es trispinosus. Fifth footoffemale. Ait. et minutus. Young, AE ON 8. eas minutus. Nauplius form. 5 ataey ane 9. Pseudo-sida tridentata. Adult female, antennule, labrum, a of shell, and post-abdomen. —— fey , 10. Daphnia minnesotensis. Young female. | Be ee Li. ‘‘ —minnesotensis. Post-imago. — -:12—~— © minnesotensis. Beak. Ay J iv PEATE 1. ZooL. SuRVEY OF Minwn., II, 1895. Ae ey x Pe A os) a Yes 79 d ~ F ; Bhs A ahmed Say BAPE AA MO ROY ~ steed ASS. alt ak Fathi chet a ; SUE Ae a PIER tig ar “ptt Oy Gets LEGS Mane ART are oR Mae M AL Nc aad Pam 02a a MERE E ne hy eh ee aE eX Daphnia scheefferi. Post-abdomen of female. Post-abdomen of male. Male antennule, S Brain and nerves. Inf. co. g., infra-cesophageal ganglion with et nerves to antenne; c., cesophagus; n. f., frontal nerve; g. opt., optic ganglion; m. opt., muscles which move the eye; p. f., pigment fleck; n. opt., optic nerve. Posterior part of embryo. Eurycercus lamellatus. Heart, showing the anterior bifid por- tion between the lobes of which is the arterial opening and valve. The vaned arrows represent deeper currents while the unvaned indicate superficial ones, The dotted line rep- resents the position of the pulsating membrane separating the venous from the arterial currents and seen in section at (a). Daphnia similis. Anterior part of the nervous system seen from below. a, optic nerve; b, optic ganglion; c, frontal nerve; d, nerve to antennules; e, commissure connecting upper and lower cesophageal ganglion; f, nerves to antenne and mandi- bles. [After Claus. ] PLATE LI. Zoot. SuRVEY OF Minn., II, 1895. Ln i EXPLANATION OF PLATE LIL. rd : | Daphnia minnehaha ha 1. Ephippialfemale = Bae 3 2. Post-abdomen, ey ee eye Se ee 8 »~-Antennuleof male aaa a ene CRY “x Batt Daphnia exilis. ath, : x 4, Female. — ; . , 5. Post-abdomen. — Ait ee Cn \ hb Simocephalus vetulus. . 6. Caudo-ventral angle of shell. The markings are on the « lamina. sake & ns a 2 ie Sia 7. Marginofshellcephalad. = Ne . 8. Post-abdomen. : i 9, Head. | - a ~~ -f ZooL. SURVEY OF Minn., II, 1895. PICA Eee EXPLANATION OF PLATE LIII. ie of as figure 5. ’ 2. Head of a common form. of ie above species. --3..-—s Extreme development of the crest. (dg Ee : 4, -Embryo illustrating the early development of the helmet. eM Daphnia kalbergensis Schoedler. 5. Typical form, from Lake “Minnetonka. enone 5 6. A form of the above taken from the same gathering. : x es 7 8 7. Post-abdomen of the above. ‘aerate . Extreme development of head resembling D. retrocuroa ‘For from same gathering as the above. psa 9. Daphnia dentifera Forbes. patie from hae =e Wyoming.” ” ni ere +4 Zoot. SURVEY OF Minn., II, 1895. PEAT Has it: rT nay aie eels VORCE E HRRe Ruck tain Vetta Pre CRA 18 5 DE er Spe ANT SRD RRS RR GOR 25 vi~ ¢ Piet ned teet aay ata 2 SEN 5 tir ms Hee, BRA 2h iy apes sy EAT eas panels Si Pay ase (hots Cee bit we \ Ne ae Stns ee . na wits td oes tae Pumas: cote hy) Sar ec a! 4 reed | “ae Ae taniale 1 2. Post-abdomen of female. ty ees iy SI ie i 8) _ 8. Post-abdomen of male. ‘ 4. Drepanothrix dentata. Post: abdomen of male. 1 Macrothrix tenuicornis. 5. Head. sf igen ; : 6. Post-abdomen. — TES ; 7 eee 7. First foot. os 8. Antennule of female. Macrothrix laticornis. 9. Head. 10. Post-abdomen. ; 11. First foot. 12. Portion of dorsal ridge of shell. PAE LIVE 1895. ZOOL. SURVEY OF Minn., II, vo aS af LANATION OF PLATE LV. Pi * md 2 a" H SOMA D TS wwe _ Ilyocryptus spinifer. Lateral view. Head, from below. Post-abdomen. Embryo. Ilyocryptus longiremis. ES sordidus. Post-abdomen. tg acutifrons. Post-abdomen. ch agilis. Post-abdomen. ef agilis. Head. x sordidus. Antennule. i sordidus. Spines on free margin of shell. ZooL. SURVEY OF Minn., II, 1895. PEATE: Lvs EXPLANATION OF PLATE LVI. Sania ‘ : -Macrothrix tenuicornis. __ a WT: IG. t vay A. Hts Lateral view. ANAS NS cca, en ge ASS Lath Vea la. Labrum.— oy cele, Ls Gt ee ihe! eerie ret 2. First foot. rea AEA Ngee Yi ah orcas RE 8. Antenne of young. HER Pe) Se CO as oe _ 4, Maerothrix pauper. Piste SACK Tee ae 2S. - - . ’ + ‘ f ‘a . bs jf : ; pee Macrothrix rosea. 5, Antenna of male. va | sO erage Uae aie i 6. Spines of shell margins. _ Pe, Renata 2 Se 7. Post-abdomen. fees Se So pie Macrothrix laticornis. Pee i: iy 8. Male. eg ‘ 9. Semen cells. | : ia 10. Pasithea rectirostris. Male antenna. | at: Macrothrix rosea. Post-abdomen. ‘s oe VD. . tenuicornis. Post-abdomen. ; » “Seen a rosea. Post-abdomen of male. ies +) < 14, Dispadotheds dentata. Antenna. - eh \ i hte Ilyocryptus sordidus. i F 15. Marginal spines. : 16. Antenna. Pes 17. Post-abdomen., 2 a Ilyocryptus spinifer. 4 ! 18. Lateral view. 18a. Marginal spines. A 19. Antenna. fe, ‘ -20. Macrothrix tenuicornis. Heart and accompanying vessels. . ~s ata ae 21. Ilyocryptus spinifer. Post-abdomen. ei ZOOL. SURVEY oF Minn., II, 1895. PLATE LVI. ase oy “2 ANATION OF PLATE LVII. eee Lathonura rectirostris, i eutin in pineal cavity; h, P heart Female, from side. | . Head seen from below. _ Maxille. First foot. Ovary. Antennule Last foot. ZOOL. SURVEY OF Minwn., II, 1895. PLATE LVII. A ae 7% vm ‘ a oe: poh EXPLANATION OF PLATE LVIII. ” i ee 4 Wr. ere Ae . ety Ofryoxus gracilis. Fic. Adult female, showing coiled intestine, elevated anus, long an- tennule, elongated seta of second antenna, anterior cxca, etc. 2. Post-abdomen. 3. Antennule. 4-6. Polyphemus pediculus. Young and adult females. Zoot. SURVEY OF MinN., II, 1895. PLATE LVIIT. SS MTT 7 Yf LU Ce th i bats: 5 os sat Ss ¥ 5 \ Feneet at did Se BIE Ee j eh keh oy as Sigs wa pity soe ies SS ea | eet Bieta eR eae Soh ie gp > Mong Fy a Si Ne, , y & - SpReS NTE LENG At ALLS LIU a Se ¥ - ie , ; ' é we ae ee, | \ Pel SEAS HS Spe. ; er: ed; Polyphemus pediculus. Swimming feet. Ofryoxus gracilis, First foot. y ~ oy ae - Macrothrix tds Female. End of post- -abdomen. Antennule. at Leydigia quadrangularis. First foot. ¥. we on Osphranticum Taba eiton Antennule. Fifth foot of female. Zoot. SURVEY OF Minn., II, 1895. PEATE LYTX. Plt Rahs Si lt ee ¥ 7 1 + fy whites FP LAE ES - 2 1. Pleuroxus hamatus. is Br Ure Ans Tis, 3. Alona costata. ane 4, Leydigia quadrangularis. ct oh Le Butyeoueant lamellatus. — 5. Male. Y DE AE TOME EA ST Rin Oo \ Sere) 5a. Posterior margin. ; att Mie aetsc 6. Antenna of female. Woah 71 Von Ra RA aT, Alonella pygmea. fede aM Eurytemora affinis | Poppe. - i ‘ — my Female. | 5+ see 9. “Female abdomen. © Heat yi es . : 2 Ke 10. Male. ‘ Sf I EB Ei Sone pal eh 11. Male abdomen. pane ait jp vipgeien 12. Fifth feet of male. or BLS x 13. Fifth feet of female. A 14. Jaw. Ke TB. Antennule. 16. Nauplius larva of this or a related species. ZooL. SURVEY OF Minn., II, 1895. PLATE EX. ATE L: ‘ ERD Pit foo M Wee, 2 eS 2 ‘ : f : a | ile tang Ret - ; ie ete ite 2. Sone Airy fed “2 “i i oe eae ial fg: y; i 3. BAN A, fy ae ge { 5. 2. it 6. i 6a. , ce 8. ; a 10. 10a. - Foot of same. : | ~Acroperus leucocephalus.. _Post-abdomen. Alona quadrangularis, Female. A?., antennale; Lb., labrum; Ma., mandible; Pp. -a., | post abdomen; An.,anus; F. c., musculus flexor caudalis; HE. @; us- culus extensor caudalis; A. g., anal gland; n. aie nutritive globule in embryo; t., tail of embryo; sae BI III, IV, V, Bek pairs of feet of embryo; mx., maxilla of embryo; at? +, antenne of embryo; at?., antennules of embryo; H., heart; sh. g., shel gland; ov., ovary; Md. m., muscle of mandible; At?, m., muscle of antenna; H., eye; Sce. g., supra-cesophageal ganglion; He f, pigment fleck. Brain, eye and pigment fleck of § same. Pleuroxus procurvus. | Female. ~ Alonella excisa. Female. ‘ Shell of same. Antenna of same. . Alonopsis latissima. Female. . s latissima var. media. Female. ‘ Camptocercus macrurus. a Lower angle of shell of same. PLATE Lak 1n fos loo) ll 4 Z S| om ° Ss a > a4 2) op) a c () N \ : . eet] i } oe q Roe PAE cae lg * Wer re Th Hy _ . m AA ' A 4 of * , i \ ELM a Oat hs Oa) SORES Oe Dy 7 BRS i appt ¥ ‘ eh AS APOE By eta ; tN fog, LEAS ce bb BES . care oP Mi teas ~ bt is cet ok , ai ight eC ‘ yo? | eS © Camptocercus rectirostris. Fie, 1. Post-abdomen of female. 2. Post-abdomen of male. 3. Male. . 4. Camptocercus biserratus. Head. 5. et latirostris. Head of male. 6. yi latirostris. Head of female. 7. i lilljeborgii. Head. 8. 4 lilljeborgii. Post-abdomen of female. 9. Acroperus leucocephalus. Post-abdomen of male. 10. is angustatus. Post-abdomen of male. 11. Alona tenuicaudis. Post-abdomen. 12: ‘* dentata. Post-abdomen. 13. ‘¢ dentata. Female. 14, ‘‘ elegans. 15. ‘¢ intermedia. Post-abdomen. 16. Pleuroxus hastatus. 17. Leptorhynchus falcatus. 18. Phrixura rectirostris. Post-abdomen. 19. Kurycercus lamellatus. First foot of female. - 20. Alona sanguinea. Shell markings. Monospilus tenuirostris Fischer. 21. Lateral view. 21a. Head seen from in front. Figures 19 to 21 original, others from Kurz, P. E. Mueller and Schoedler. ZOOL. SURVEY OF Minn., II, 1895. PAE Bs eee! DRE 4 AP tT mn) ee & AL i oe a Us rE ar ee mea? 2 ea beter ery Vidar x rx ete y W 4 Pie | L*e 5 a ty ily SAS eas te eS, mid aay es ~ Alonopsis nti ae ay Alona glacialis? Female. nalts oat a i i Be as Bf) otk Welt Male. 3 pie Gl pee Alone satiate (?) var. . tubereula Hak ss Ae Lateral view. — hotly | Sr ouck Wek tema 5B. Post-abdomen. i So eeentae 3. _Labrum. ; | a a Hh Se ee a 7. Antenna, setose branch. ; em se ae ; oe 8. Alona glacialis. Antenna. — 2s EA Se Sea ay 9. Alonopsis latissima. Feet. | Subs YS ea G0; 11. Alonella excisa. Details of shell sculpture. _ 1 a rie BL Lt ate See Pleuroxus denticulatus. — 10a. Outline of eqhippium. es) 12. Female. : i set sagt 13. Common variety. | 14. Alona glacialis (?) var. tuberculata. ZOOL. SURVEY OF Minn., II, 1895. PEATE. Xr \ EXPLANATION OF PLATE LXIV. wy » ¢ 25) , i] y " \ Chydorus globosus. Fie. a = ‘aft OO eer * 1. Side view. ; rs hi eee case | 2. First foot. “ie Bee dt 5] ae ee 3. End of post-abdomen. 2 teva et oh ae 4. Chydorus sphericus. Post-abdomen of male. ite 5. és nitidus. Post-abdomen of female. ra iG. as nitidus. Head. | as “eo Es sphericus. Ephippial female. : 8. = sphericus. Female. ; ; 9. Bi globosus. Post-abdomen of male. 10. ce sphericus. From above. — da $ ovalis. iS 12. 25 celatus. : BA 13. Dunhevidia setiger. as , 14. Alona affinis. 15. Pleuroxus gracilis. | ag 15a. im gracilis. Antenna, Bs = 16 ie i ; Zoot. SURVEY OF Minn., II, 1895. PIA TEU Xiv: Sand ees ath fetracs . Pet tava ne Sehr te: A » Bosmina striata. x longirostris. M cornuta. 6, 7. Pleuroxus procurvus. 8. Graptoleberis testudinaria (var. inermis). 10: Acroperus sp. 11, 12. Graptoleberis testudinaria (var. inermis). PAIRS Ie xeVe Zoot. SURVEY OF MINN., II, 1895. yy aie SY (lanl ~ ‘EXPLANATION OF PLATE LXVI. ‘ by Lal @ Streblocerus serricaudatus. Female. -Macrothrix borysthenica. Antennule. Pleuroxus griseus. Female and post- aa Ceriodaphnia cornuta. Head. Post-abdomen of same species. Daphnia lumholtzii. Female. Leydigia australis. Post- abdomen. eel 2 3 4. i 6 7 ‘ PEATE Mx Vas SuRVEY oF Minn., II, 1895. ZOOL. by ; Axial r oe GYRO AaE EXPLANATION OF PLATE LXVIT. ; My iene se Cypris herricki. - 9 a Dorsal view. oo Lateral view. "tes One of the first pair of antenne. One of the second pair of antenne. — Mandible. ; 44 First maxilla. . | Second maxilla. First foot. Second foot. Post-abdomen. SU, woes (f 8. 9 0 I. Cyprinotus crena. \ Lateral view. Mandible. . Feet. ZOOL. SuRVEY oF Minv., II, 1895. PLATE LXVII. Vv pa ’ £ ef REA RSP ERE DY 5 EY Soe Ba) Sina Bete : i Se Eee FETA MPTP SA vce sd XPLANATION OF PLATE LXVIIL 4 Ps) Ke a eee SC Ea Cypria inequivalva. Lateral view, female. Dorsal view, female. Ventral view, female. Antenna, female. First foot, female. Second foot, female. Abdominal ramus. Verticillate sac. Cyprinotus incongruens. Lateral view. Dorsal view, female. Ventral view, female. Antennule, female. Antenna, female. Mandible, female. First maxilla, female. Second maxilla, female. Cypris herricki C. H. Turner. Larval stage A, end view. Larval stage A, dorsal view. Larval stage A, ventral view. Zoo. SURVEY oF Minn., II, 1895. A PAE eV nite, ¥ ae ee : . a a ¥ ey. / AN ¥ Fie. a Fis 18. 19. 20. 21. 22. 23. 24. 24A. 25. 26. 27, 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. 39. PP, Weel wt a One ey ae ee A Re Mk AR re ak ee Soa’ Ube ort sy Pied, Bs ) an) .” “ Cypris incongruens Ramdohr. First foot, female. Second foot, female. Post-abdomen, female. Portion of shell. Lucid spots. Cyprinotus crena. Lateral view, female. Dorsal view, female. Ventral view, female. End view, female. Antennule, male. Mandible, female. First foot, male. Second foot, male. Post-abdomen, male. Verticillate sac, male. Copulative organ, male. Cypris Herricki C. H. Turner. Portion of ventral margin of shell, female. Stage A, lateral view. Stage A, teeth on caudal margin of shell. Stage B, lateral view. Stage B, dorsal view. Stage A, post-abdomen. Stage B, post-abdomen. Stage B, ventral view. ZOOL. SURVEY OF Minn., II, 1895. PLATE LXIX. ” Peer eS TE Py aaes | Mest ine ec ch da a t 4 ~ 4 : Pye ; A . \ PARES SiP ATi We heP = I Ge Sota eor.e oe ae | } a Suh Bae marae karen? ay0k eet hire eee hut UTR UReE. 2 4 1 yet Be Sa ure Cypria exculpta Fischer. Lateral view of the shell of a young specimen. Second foot. ; Lateral view. First foot. Shell markings. Antenna. Post-abdomen. Second maxille of male. Cyclocypris lzevis Miiller. Antenna. Post-abdomen. Second foot. Cyprinotus burlingtonensis Turner. Antennule. Bit of shell. Tip of first maxilla. Dorsal view. (Fig. marked 692, middle of plate.) Mandible. Post-abdomen. Antenna. First foot. Lateral view. Second foot. Figures 12 and 13 have been cut out. Zoo... SURVEY OF Minwn., II, 1895. PEATE hx Peery rer % EXPLANATION OF PLATE LXX1. 7 . Candona ecrogmani Turner. ‘ Re ert Cp - 1 Fie. eae. _ 24. Mandibular teeth. $ tie nt aa Antenna. Ste Sensory seta from Pe ae palp.. pat Antennule. : 28. Post-abdomen. 4°. 29.. “First foot.’ , ; Phi 30. ' Tip of second foot. ra RN Ne 2 Me 31. Mandibular palp. geht Bae .) ; ; ~, .©-82. Dorsal view. MA cid ae MERE: 33. Lateral view. Been cis: ot Poot he 34. Candona acuminata Fischer. Post-abdomen. A ira Bar Candona delawarensis Turner. 385. First maxilla. 86. + Post-abdomen. Ponies BY. Dorsal view: . .. 38. Ventral view. eh cute 39. Lateral view. | : 5 ota ‘ 4\). Antenna. ’ | = Cypris fuscata 41. First maxilla. ; 42. Antenna. 43. Second foot. 44. Mandible. 45. First foot. 46. Post-abdomen. ‘3 PRATE, bX, SuRVEY oF Minn., II, 1895. ZOOL. Fie. 2a. a 7b. Cypridopsis vidua. Female from above. . Antennule; 1b, antenna; 1c, first foot; 1d, second foot; le, man- dible; 1f, maxilla; 1g, labrum. Erpetocypris minnesotensis. Female from side. Antennule; 2b, second antenna; 2c, first foot; 2d, second foot; 2e, mandible; 2h, abdominal ramus. Cypria exculpata. Lateral view. Notodromas monacha. 4d, second foot; 4f, second maxilla; 4f,! second maxilla; 4h, post-abdomen. Cyclocypris modesta. Male from side. ‘*. Female from side. . Antennule; 5b, antenna; 5e, first foot; 5h, abdominal ramus; 5x, copulative organ. Cypridopsis newtoni. Side view of female. . Anterior and posterior margins. . Antennule; 6b, antenna; 6c, first foot; 6f, maxilla; 6y, lucid spots; 6h, abdominal ramus. 2 Cypris fuscata. Side view. Female. Dorsal view. Antenna; 7d, second foot; 7h, abdominal ramus; 7y, lucid spots; 7p, a magnified portion of the anterior margin of the shell. Figures drawn by ©. L. Herrick. Alabama Crustacea. PLATE LXXIf. oan s : ‘ 4 {Py - EXPLANATION OF PLATE LXXIII. - TSOP OL PS Lateral view. Dorsal view. Labrum. Jaw. Abdominal ramus. Natural size. Cypris perelegans. PLATE LXXIII. Zoou. Survey oF Minn., II, 1895. EXPLANATION OF PLATE LXXIV, Bee Oi Ree re Cypris virens (Jurine.) Labrum and both pairs of maxille. Second antenne. First foot. Second foot. Jaws. Caudal stylets. The following figures of this plate are not noticed in the text: Gammarus dubius Herrick. Streptocephalus sealii Ryder. Harpacticus chelifer Mueller. Laoponte mississippiensis Herrick. Canthocamptus mobilensis Herrick. 7Z.oo1.. SURVEY OF MINN., IT, 1895. PIA execs abn Aah: ©. a 7 ae bse ke Cypria opthalmica (Jurine). Ventral view. ‘ Lateral view. hoe a Da ae Posies Dorsal view. > ; -Cypris.. Dorsal view. oat Cypridopsis vidua. Lateral view. eae ie vidua, Ventral view. a taper amas Cypria opthalmica. End view. Cypridopsis vidua. Dorsal view. ve ma ae as vidua. End view. tae Candona fabeformis. Dorsal view. aed? “ fabeformis. Lateral view. “ ZooL. SURVEY OF MINN., II, 1895. PEATE, GXxv. \ _ EXPLANATION OF PLATE LXXVI | Conn or Antenna. | ee sis "2 oe Second foot. “eh ELEN, (oe) gems Abdominal ramus. ? Cts Ae eo Cypridopsis vidua. Abdominal ramus. | Cypria opthalmica. Mandible, gill missing. Candona fabeformis. Antenna of female. Cypridopsis vidua. Antenna, ~~ Candona fabeformis. Abdominal ramus. Cypris fuscata. Muscle scars. . ) d Zoot. SURVEY oF Minn., II, 1895. PISA Ee TeOxeviip EXPLANATION OF PLATE LXXVII. < 4 Le te? ry q ri e hers \ . ~ : fi * - S g ‘ ae Z ) ‘ : a i i : 7 Erpetocypris barbatus. : Lateral view. , . Antenna. _ Caudal ramus. This plate is copied from 8. A. Forbes. PEATE OLX XVIE melt pia, i “ + «EXPLANATION OF PLATE LXXVIII. ry PS et oN Cypris albuquerquensis. Lateral view. Dorsal view. First foot. Mandible. Antennule. Antenna. Second foot. The figures on this plate were made by Professor C. L. Herrick. PLATE LXXVIII. Zoot. Survey oF MInn., II, 1895. [hit \\ wut) eu) i a the RAS ry ad A : ae be. nega , , Up ekay ey 3 x 2y TE LXX Jr2s dp a eur 1 , S _ SO SP Se SO ra a 10. 1. 12. 13. Cyprinotus grandis. Dorsal view. Lateral view. Palp of first maxilla of male. First foot. Second foot. Mandible. First maxilla of male. Abdominal ramus. Antenna. Cypris altissimus. Second foot. Muscle sears. Antenna. Abdominal ramus. ZooL. SURVEY OF MInNN., II, 1895. PLATE LXXIX. EXPLANATION OF PLATE LXXX. ce Q s CONIA w . 10. Candona peircei n. sp. ets 3 | eat ~ Antenna of female. - Antennule of female. Antenna of male. Second maxilla of male. Lateral view of male. Ventral view. Second maxilla of male. Lateral view of female. Abdominal ramus of male. Copulative organ of male. Abdominal ramus of male. ZOOL. SURVEY OF MInwn., II, 1895. PAT ee ke. \ EXPLANATION OF PLATE LXXXI. ~ ] a; “ —* > y ‘ 4 ie Darwinula improvisa n. s ‘Fra. et ae ue? 1, Antennule of male. Rise | ib sss Tip of second foot of male. a iernraN ey, 3. Antennaoffemale. ss ¢acnevsuses sedges ee tenes Reeth te aeoneeee 244 (63) — ETISED Soi osc escuitsdessuonsuscpacd stunt bebsue ppapnign pba acc euugt ied ote Ree hice a eee eee ae 248 PUGIATAR wetness cc sescoeastese ed ub UadidascugnvaenoeAtden cabeeaee ents 2438, 242, 244, 248, 249 MORN MED. 3 «concn 5044 dhse venesateSscrndaey'ssinwnnCcoshpatbi'aloaminhandl nese ea eee te aaeee nee ne 248 PUSEU TEATS uci duns cad eenbectaet en fede aibe enicherane chars Mammen OTs iit eetalicnadeciashe ah Geyer ee eee 248 ANGEL Eda. sstatasee cuscecenorenpac space sae tenes ee tee eae 244 (62), 237, 242, 243, 275 NAGUBETIS s esedas s. seodsbavas sovees cosdaesés dogs ve tqacsetaumer uae: eee cee ans ee 242 TADIBBLINA, 05 stow ees oa ivber bates sens benwacw te dand cea taseeeemec dae bea. apoio ai aaa eee 248 MEPIG chi s5 5 du donee s dodnadoavnctaondcovtsa vans aneggey dee unueae Save Pear uce eet anne san aa 242 Ley IIA co. ca tpecsSeesies to owaore de Osabonbea caaseesh aoe ea cased y suse Maan ak gen hanes oe eee 248 BV GIP doccccs scadadvep es ovatus ceingurnsaie sap sesen aleeetur ngs misewesaaatigs danse tena ate ee 234 WTB AGA se jeecssls aztec dectcsseceeneerstas Weereoen tare eres en eee eee eee 245, 247, 248 MAUIMILD 16,55) ne oielssan dap ann'sasdcedhe ten canbon tyete bana hbeen Ueetecdueaaae cesthaas eeeant aie annem 248 AH OUERER, cass c 2 vas phos cease vavee Dike sasieceaue cedure Lila een (13), 245,°248 MONICA 2.sc ca pcssanewared neste c ceee co lteloeoycoees ness Wnee eee icoed Cue ae aan eee 240 MYMIVUS: 5 2 ciate ssc accsneccesldars be edsccieigencvusmedavadesatcercamesw arena as canes shes Soe eey .t Senne mma 248 LG: oa ah ds oa oo on -sedes vdecdaversuctaapes ake tasaPele ee cade atceeteeeena nd ee ee 241, 240, 251 OVALD Tee secncschectcctquvsiness coc sducdeneate bodeesmeees cen ih Gonene tatoo sor as none eee 248 DBE W Uo esos se olcs Sinesede Ue sudo-; cote gua ve cat eemasie tec cee tes eae Seen 248, 242, 244, 249 parvula,var--tabercalata sis csi. ccectasna tious tatbeckeces canuunendees tA Reenen eee 243 PIOLECCLA fos casccs heen so catesesen os tings scnenena se soe ca con cuheeceas Coat eee nak cane eee 246, 275 | LLG Lc ee ae OES PPE Mun SEPP Sopr Soba iy AEST yl ee PCa efi e 245, 247, 249 PY MM BA iss vests vessecadaseccossaesea nels dadeasoe laGusvs! sng ctusches sperma cr omen eames a Sheet Rianne 249 quadrangularis................ As waschee deme tater tart ereaae 240 (61), 234, 237, 246, 249, 274 POOH MLA. «oo saya ka swale ones echesevesad aig se net tey tetenme cya ce ceeeehtnk cout ae iene ane 245 TeCtanPUlaris..:<..seacecaves Aste decet gecesesicenetsaden code lean Mwecusnttuedees rete oet anceay aemeame 249 WOULCU AGA, Sst took kev atav sla ces Oy posman bolle cies etace taee pelteles oie eae ae eee 236, 249 MOSUIAUA. o02ceccecaceve tain ssmsensstoccnotidneod cevsetumert scutee eres mae on es tener oste nace eae 249, 250 SAIS RING {asi . otis ccenasaassdeadens sooeece cece subegh teovh cohen teenie eae eons 239 (62) BOCOIS <5s5c0cccccdeseheresvens seosncsesavoreveddcicadeancch ne deck cecscere secssadaveccencsns dtcen teas eemne 249 Spimilera. 2.0... srccirssldet vavthaoTdadany ee ston Batt doetn aoe die eee a ee ee 241, 249 SUA MALIS. sii 0s oscivdbe sda va cee'd cSocuebasacddnc soetedeaaee tack weeden weet teeta sae eRe eee 246 Grebo 500 ot A isdaveafesbacew tec dcusl Uneentens odpe sete cence lee beate eee he nee ea «249 UU LCS 1: Sap ret a ice eee eer aie eid eur) chy sO Mer eae cn eer a SAE eee ee 240, 249 PEMUICAUG IB. 3 o...5 pennies vice sia pabdeceanesdeneanecy bene eee es Glee eee 242 (62), 246, 248 LOSEUGINATIAL 5.5.0 -5cstsecnce, ses aweseasieeucatenendan cas evmene at eee bee eae eete ee eee 235, 249 UP ANSV CTSA. 2 oisiod oss. «sts venacans aetiwtep vd odo nceneereaeanladdotee ss saat eneeee eae anne 249, 253 UU POV CHA GAL ci... hicdcedeaconendt hong ete shee ae aeateee A Giode deeinkta sc aa aeeneee 243, 244, 249 WELTU COSA. conn cccwate ates cetouuene cos s¥ceoeen dacciotasetbsdentendarnsds «teas EEeE eee aemeem 243, 249 Alonella............ As SCENE NOS brderik MANCSSo k 249, 235-238, 248, 249 OX CISR ved ecoajcccsna des egeaGaiee eaatonGene ces caeuate coer teeet 251 (22, 61, 63), 248-250, 259 ORIG HA U.. skis saws sloaceae Res coc denclocmee seen cick ieee rave yar eeeennems 252, 248-251, 253, 259, 260 SUISOD.icbsc'es eve endce ies vacoweceee'an cece ceeecadeueypecehius sodeeaeemeet eee amen e aee tence eae 252, 248 PULCHella se. is ackbordwes ove exe sone 15 ute wae ne eee a cktes Ne ae RE ce eee oe 250 (13) PYG MBA we cso oe ssavtau.dcstasnweradecee achiowssdadeees team seem aamestaeees 258 (60), 248-250, 259 TOSETALD.L oe cicliscdabusvesescevasenns vet vee os Leucesc dca ek Sede Saad ade ORpRane ne ct eee 250, 249 SELINGA. 3255 1.5 cockbvens bcoceceassaees mcewer vende hae ecuad on ae ac a ins See eee ate 258, 249, 259 INDEX. 509 Pe NUREMNE RMSE Eee Sen ec eriev ea dev ievin sh on seu cp ielveciscueWcacdnes. cesave-donstesax 231, 143, 237, 248 PROMI Livia eet nee eniets Cabins Uicioastosteoracoicauh condos dateets iceessluas sicwec cp evedesah bees 231, 248: JAGISSIING teesces.sccresesss “an ES tary A Re re Ale A a RS 232 (61, 63), 233, 248: MEP ee RULED VATS COIBG aoicacasisesssesesdand sare sianvelea tae sou dunnannetplindaadcan eget . 282 (61): PRVECAUUS EG ONINUIS cor rae lentes thc oow tie ae nc ccna snasnlcce. ce snare Weep uss dese dese Soest evacpoesies 264, 257 RUE UM ALM ccaenae ray ietianut esc scicddiieulgne tine ava chap wspaciieau'or clades sashes es te svaes eneebeMoetde 264 UPON RENIN UMIMNER SE, (50 22 POs SOE ch), Sec vescpaides sous sNcomeds Speusancciun cuales odeomeete sie 145, 146. PRU MME WEIR iis. \tbecsmaciccccaces cides vedas sbeceventsts ses ckepeseasbodniecheesocecentRseatesedentaveceus 1386 ASV SIGNS. Shed ogee Ane SS Ane ape nq ease q oad bGee Foor oS SHOE eoane Lar esanoce sagcecr eric 135, 136 2) SLED TEE oc dnd Soh dadichon: deer CaP OOC AIEEE 00 BIGde docgd da EBCon aes co diddrnuis a suterenadsascecoacciice 136. PERINAT Se ei RS A AP Be oe i ap ire It Ey SAT Ao RE SORE OE oe Ee 294 SNMMMNAPU ATER ERED oes Sac ohne vik op cbeva cares tvs seth dustacdsagnddenesarcsiates leshelameccrseie tap ameas 9, 280: HEMIDECICE Ned DTASIRIONBIGY oce2s5 ccoscad Sbceesoce cases suncenovacates deveasaa Gseecececeehuscentamarstee (11) DUA ULIC UNAM entre tacnses tocdecekvndet ees covas dcloateroos vances teieecees Peidandusinescene duces teers (11) RM INMNUE GE Soe ce SECs ce ceva tac cukens sousts abe paces Sevonal «used 2CG (sp.? 45), 143, 214, 215, 272 HIUPATITACHS IN ee eas cnteon sic ctsclais eve bt pues osisieia sfaee atten raatebapebissiee ean uieVa eenatsleae 209, 273. TIO MO HTL Caer ees cee teneccen lave secs teacrecbesk tence Tesceneheapestne's aie 60 sige be avis cea deins evelstieten aaa 208 SPE VICOTTRIG Soe oey eGo, oe articles cosa ein cco a caecsesstabins cade sed aees nas Miaegenaeeces sacs damian 207 PRE VALOR DIS ous caisc rast hancaess oes tosis cco none wend ddidas dean naes cooedene ie cmaanes 208, 207, 209: CORED OWT rc evscecciansasapsecécesce>ndeccacasscsstdtasideslec¥ecedvasscsensclrersaaswsransawesunsralaces 209 CURTSTY TIED, ABE GONG Rep ROS HORE A EEE EMCEE CEP REC EEe t eee cede Ven eeeocaaceneeen 207 (65), 209, 272 IEPRVELOSULIR Mrs oc occ cule ccs ce couch c/ssaletelade canis aaeseebevacdsecdew nieces ra ae dossiers smc stlabiatamnslt 209 MURCUPDAATIALs Root ass soecidercnaseenesied seer secede delsivesasisisouanievnenrs saabindhisdeainssueeliemoseensl eee 208 SUMOLA denote ae alls cute wiedelieaainicncenesanlanayailsaclacceids'sior taie'altise’s sSols'vse'segr'seirisaiiaialeatvaduenaeueis 209. MAGUS OLIS ebucere nk cecncek octnGee eces ances sce vonachhsceas Seu cules sive tineGincawen ae seen seetuassieMatapeiienn 209 NERA Set ae eo Ge asacl tes caniculests auigdeased ancwecbsepdnadss desea mesaslemctesacsiadassehoaseaneees anata 209 MOR OMPALL I Ot Go ocactgdas an'ace shave cuvabedtnce'ce) sues eshoceueasonlavore'ys Sdpaauanan 208 (45), 209° TONE OUISIS eee coeonc ci Re ketariococcc ce akanceb sone baies'e wits selecels clonic cise cise aelsine slstiet quem scwiatamelteneey 209 RC OLE ope kha nok ces ocr ti Gos exstncceaaed bomaegps sb he'ebie ab tnpseeusesaitdedeneneMewakeaeeep 207 Mi AEAUROM RUIN cance oat ouoylacaasswas> 1275 cia>adseh vauadiauaveascemtspscversesaetmasaye 207 (45, 65), 209° MACTOTHYNCHA.,..........cecceeescececscccsscvcccccccescecetacecssceescucsssees secssenscesedenwenens 209 TENE A SS oo cc doe ak oh alin ndten son Share taal Oho wad la'e 64525 Aas banasaanefannee sapien te ane eee 300 GLOP USUI. fc oSes set sede. ddgapmacosstney bpsowsk dus atin den Meseneneaele Gestereantcea ee 300 (71, 81) CLODMANIANAL 2s... toc oc cee cscednacs taeceesiesysosp eieeeesvcusibincsesisissam anit cislusisieinniaias(s Fobcasueneteas 300 GOLA WATONSIS: /55t cot.ccucyeccacwarpee angina “sa ebiaethnahendudeesnedd stasis mpantivage theese 308 (71) GAP HANA. o07- 2 se oncnee senciadste qe asbniscaldnenes nes /en ect sittin ta crecislanae i neaineiteaas ieee eet te eee 299 PALE COLITIS cast hc'asbsula ty eee pe anelacstpeeca sta eenemenpARes ine dachodiaente Sie eee 299 (75, 76) TRS PIG oe on aca cc aves sue cu eater cetievedad ey tees eeeraastet ae amene 129 PTACILIS( ener ce cwerseseccecss pene Donec sedescvanidhescisuetdswtullevatuestmeionsusennecterenteeeet eee 129 DUDEPNICHS A si cds ots earsanes ; bv ompinaadaiasacbu Sashienie dene teen aah eine tae aie 134 (50) NGVTIGUSK os sociacesncise bate cacch’s sdvects saeteseeeus hess sie sasenaade nates testetendsn eset ee enemas 129 AWINGIGENSISs 212.5 's's.scesacCheaeecacecucesdevep counw seein lan edeameaseeleenenet Caen ceeenten 1382 (29) AUN@AVIS! 2h ecciceccdac ay segucthccedoesetscerceencous cadetdesceee qoene caleawa eee nee aad astedeeh Samarra 129 MATCOGICUB: c::ccecveveesTacds vosissseasce'aeSatmoot cede cleedarenend astoetatmens engiean call astteae a manne 129 ATTN ESOLEMSISs 52 orsicascacs eoearuniastaccetebacance es ssea ete nsedereee erence aaatane ceeteeeas 135 (22) TMT EML DUS aycaaniey teenie tet es i ansatouns bang ake manets ovanoacadacevasneae packs Sock ocesured insite’ szade anger anes 110, 111 lucidulus Vosseler (—strenuus)..........ccces cesseseenecsconseecresensenseneeseseesees 92, 100 maarensis Vosseler—macrurus. WMACHUOUS ccudevccctsvatesns cisacsccantscocopadteccpoteacte varnesnevynenssensisonsslantesaelnsecssanasty 113 magniceps Lilljeborg (=? @quoreuS)......-..c0esceseeeeesseenenseeee seneeecenseneeereesesens 122 magnoctavus Cragin (fluviatilis Herrick)............ccesesseeseseeeeeeeesenereverecenes 114 margoi Daday (—fimbriatus) ..............-cssseeseesscseecesseneeeeee seseesescneceneceeceans 121 MINMIIUS............ cece ec seeceeeeeeceeceneccncarencece enenseeaeesecsensaneeeaee saneaeeneaeeaes 103 minutus Miiller (—Canthocamptus; of Claus—diaphanus)............s0s.seeseeeeeee 117 MIMGHGBETIS Co oicchonseieccs Vaccocsadsvesstwesseccncceunetecanestonvane «ash aecadubasscmansncae 108 (21) TLAVUS....cccececececsctcccsccncccsccssecsceccceeceeeseeseesassssessescsenseasooreesewensswewessesecnnes 102 nivalis Daday—? obesicornis Templeton—male of signatus. obsoletus Koch—? leuckarti. odessanus Schmankewitsch—saline var. of bicuspidatus or helgolandicus. PELHOTGIGES esac k et tceccace ccuoeends tone sree benae Cove de geselgcsstes ce sages © Seton caches vecetna 98, 97 oithonoides var. hyalina............... fives taceaucwaaraneees (otiuesiceitsehacl@saeeunaeantncaancsts 97 Orientalis Uljamin (—varicans)...........sscscsessecssccenceecee eoneueesssseessenseccesecsers 116 ornatus Poggenpol—?; of Rehberg—clausii. paradyi Daday (—Strenuus. )........ccsssceeeeeessennecenceeneerecensensneeeceeseneceanseaaness 100 DIRE a coictcpisoy vay caus tow nendeeeds'acevcce se sneees ve 98 (20, 21, 23, 34), 90, 95-97, 99, 118 pauper Fric (—fimbriatus)............ssccccsececccssscceeeeeecsneeesensssecceessneeceeseeanees 121 pectinatus Daday (—leuckarti; of Herrick—bicuspidatus)...........0..sse0++0 96, 101 PECHIMIfFEL. ..............ccecccesccscsccceecsseonsensaranses paccescreeseessecccsenscoseesseners 111,113 pennatus Claus—signatus var. tenuicornis. pentagonus Vosseler (==prasinus).........sssecesevevseeesscnecsrnseeeeeecesesesenseaes 113, 115 pentagonus var. vichyensis Richard (—prasinus).............-++ BA Se a ORAS ne tons: 113 at H ne ae ‘ 514 INDEX. 2 Cyclops perarmatus Cragin (==phaleratus);. rc. s0scinssgeenes vooknweurincopenes) aves tankvaemegeenten 120 PUALOLAUHE cc feo cee w vi osis caSsoniv ins cncend -Siiea kexts deoemee ae 120 (17, 18, 19, 21), 117, 118 poppei Rehberg (=fimbriatus)...........5..ccees soa nancuastnassoswsicaedndedvengseaeebenens 121 PYBSINDS cc. icas et sascomseb roan ssereee ch vunaceas catbepemecade bus acu deus crave letasen pease teeta 113 pulchellus Brady (—strenuus)..........ssceeeeeeeees 101 (27, 28) 93, 99, 100, 103, 111 ~ Pulchellas var. HAVHSS. sii, 28s ssse cen one ons iosans siaeptomenancen be bace the Gap aelyenaaelane ace te aeons ie aan 200, 201 PECUREA Lasse ssccecseescosennsdesaipsnhs'es en pedases tes gu nbaee4) hecesnenn ices seman keel eam 190 > ALEINSONI 6535502 ivctsnonses soon sect tdnneosee arnt sseis aaeenensensedenGetat a see macva dea cee eae 188 DUTILD 5505 0cocensoseceesccnaesvade=tncadpese apes bs appesctes kassvenessononnt ne kapes = aeaes cope 176 DOLOHNONSIS hes s.ccee3sdeenesscncossascae se soliweninsngsascgreanniener see soneMban ees sie eaten 203 bolivari...... PERCE EOE THERE EEE EE OOOOH THEE OPH OHETEH TEESE SHEE EES OFFER ERE EE EEE HOTT T ESET EEE SHEE EEO EE 205 - Daphnia INDEX. 517 RPUENRIRIN ER er BO cast te tcran he ee deas al Te nrenath gets axeddspamsewaa peas naam chat pecuecp eke 162 RRM Reale tei tab ane na laelag's dui- avons Sup aaielu Gk ees seen’ ot wb asec ongeac Coch Se-vNag wi eeaee 216 DYASiLIONSIS:. 60. :ccses Ruddunis dshcesagencecleseseseae AaRR sabe Meat te eka cues oeeen Mae duomt eek 206 RIRCNMCIAG CR eete nat tie), Get stlook prepa ScameGchGcstpst ache aeaceau'te sectetaswecaSonccce towels cacetene 205 brevispina.......... Peter ease tugs cesar tare aaneasoch cebee Mares «ase whan uhsodatante a Gnleyaoed 198 See MEME R an Ena a tabh ciise Ten feyiry senda cera, evoey el rs dcadeas cavstere 205, 189, 198, 206 GAMERA .c.- cosets» 92: Melee excNan seieunitas vedeen avast aaaal inwueantaaveagecuatp eects tgenstl anata 195 SDA REMVIES MRR ecteat ete wel licacose ces Siacac cro epesay es nse tes mvalsices sce e op uocen tenon aes ae 200 MRL eres ord a cas eo seen a itn sogiasin Sos design naka ve aah vs nda paiponenste ceases tooeadties 203 PRIME MRE detest acloe ste oan ecisese sae cnaWesited«sowsapeyanasadake'see vende \aedenos tn cee eee 206 INI ME Roe ANNs Sata ceuk acca wiol oases ss ases peipey bees ve oa dsaats eubecteeleod ate 188 GPVSEAUINA. . 052.2. nececeasces SSslesine¥ ven nluw gives puoats esas ayreshes nods fatieacksyt ts useua coommereee 147 RMS ae sy ae ass. Se ep waves cst vtvenarals Saf oo 8 S.cs coesay elses anaeadionaip Sea ¥akov seem 2038 SRE MAE OU Uy Mis Pond, Fano 2 ac Gets csisies anasedqiaadedesicntarstauter eapela 194, 211, 212, 218 Gegemerata.........ce...eeeseeeesseesesseceseveccasseresscessssccsseres as stay niglaledis sSamoatawaae eeleate 205 BPEL DH Lia Pe tetas pcedees dasha deott dasutaelesncsenocceeceeestscet rs Se dodaeanernaenes pease ae 201, 202 SEM en a Ys 1d Catia ra sena seaiues¥acadunasccesecenesvak 202 (53), 188, 189, 201 MMB RU es Mid bic T os tilt ete phdincl« Jo vcansedkcces «sansassiedontapaadecragck sade eecteee 196 (49) SPU MBN ce radia a Onauh x Sha 4 Wu's nfo sins ininin usaiside scidueh a hen ehncavewAoesadoienes posse us chds yaad seaeaty (22, 27, 35) 195, 197, 204 SIME asi vaewistew raves thee he Uwenuvnyacts's necisdu es CevaninsanssiausuartdapwonneWseradaciteceaeuddetes 191 PERBGUIS eve prosnerkeccvejanuesnuastace viene cnaceesBberccs unaceccocssepopusuanpanedsededcecdncwacetootves 195 Eun Anan cestle aden se vate'- tis vanes soe Sant asesesush occas einsacaveponeancecesecamecee net no eee 206 PRMEEMORccfe sc 'c'nsinfesaxelevs vaivsinsuin'gshmseuiscussevees ese tencaceds acppasapasnodyaaxeccna cescuneetanaeeoeeens 205 EMER Suited got, sess 1. oz ooh 24s puns thro daw aonsns prapen ada uceoed tujche py i ceases ead ae 192 IESE ATAN eed celpe ee aesv snde seer ae mma sadjen casas, Rervastas cps repasrsacenetaeseactiagede oh cocemer ante 198 MRR RMIRA Riis gu vis kieta coms sins Ponca ad ga nat 2S cel6 ds Sales 195 (22, 27, 35, 49, 53), 196-198, 204 BePEUSRAN 7 otrs anon aubral tn ine aasael seuideccwbvin a caivye Ecdnasec inet spomseeat 208 (27, 53), 195 NREMIN BEE ca San Sau eRP GA sia oclo anhns samcdeenoRGne Padgiecapas f caompu sotasNaateacton tae’ 205, 206 RUPEE CTISIS 6s. naitee cence ss ch adacsd vec oo sodegedetacecaasesnatic cae sacs on carat tes sons noe hee teas 206 MERCIA EIS Reese tre cinsdd twas se sacs acerca Sok onde sateca nie Gate vias sap eat noetns anecae aoa tenets ceLamae 201 ENS ee mene aeiecd sess icelicaiss anes saslitenusuesioucs adheatesea since snore cmenueniteraot seseenane 195, 197 PRL EPMIMI A yt tes ovaxcMacnnaaerncnsaach ss casein Riehl eb Senmnty's ate Sa Wades capes ee nee 202, 206, 272 MIMI MECAUIIGN Js 2 ohn voces En nniesaeancesteceds don osusnh'sass shieee 199, 189, 193, 195, 200-202, 204 MMII. ne cook acsis ics thre sae tie ois Supe eawkat aah 4a eaba says sunsgnsedees ean ivecr pete 206 (66) TRACTOR MSU Is aries deities weiss ausacuscslcpedciseabecsevijsus ca cata aatcseluescissnstionancene aseaeeeeeaedt 162 HISeMONAM rena cas nist a'aacos sseaebabev alascoucspsisecsessaptoncne aveeadessloee sack ccertiscscacscesCenemeee 206 MERE ERs sirenaicefen Se 45 ance’ cei gies avons cbaei rh oxvaenceApuepeawes ee Galena dante adh hdtes sisindnnea es ghenine 187 ACB taeda, oe oes coho arn ao ude stan cottandntcnabasnpseue rad evusdsadsiacinesent cae indian ek 202 SUMPTION LEN ace Fiche a etn ens es staaian saat adtenteh? os onaciestd.0aa Sete Snipdaoweh seenesk eign seme t inca 200 LIT GLC LCT URI Fier An ie Sy COP RE ee ee RR 189 (49, 50, 52), 199, 202 RRMA NME MELEE Ce ces ttc e ast van sn since hon clesus Wah igeensiuny sgeivaat carescperetsbicese (eee 199 (50) INC LOM MU ret ecnes desltd onahaes tac cle poe saree sea sere onaee's edaceWcec tases one reidenoesamsceuoa tempest 174 PMAUICTON AUS VATS ACU LE TOS UALR oc. cape sjsineosns ce wenaseeselonesanwaesass crsicciccdsacecneceeasuer ees 175 DVN HACIA cece snaneancede + tuenecnert carlusacsoest one sea cee taser oceendaesnsdecsavenesasmoasecematte 216 MAE REED Binet ts gone con phad ams orca Ant seu bank one cotsienstun rains dled cacinevasvacAmcmaacte nated 206 PRISM esc ceed enn eee aah at isk cer ee ten week ae cclesca ecw suin eoapelisv aapscosaetercaeas 191, 192 REC Mbemeenseeeetne ce ch ees aereniencascateniascdecassecces tention ccaahcascsscueiuate fecedanssaeesacee 192 WRRAPEM Irs sarah Sagincan sh tae cogael Gotmcaies «Water scsane sue ox eateupincntones qrvesbetuccaveseace yaenen 191 PemneR ile phaceascate neta catmeixaAcateccalesiph cnsaroe lacus dubecaldeecasrace nates scusiyp sap berets 198 518 INDEX. Daphnia pellucida............ SSeeknnbansepevgeswebrd ssbsueres WonesueveWoh bush suse acne clash Gy ehioeuanntine 195, 196 MONNAGA Sos ak caieenae net Sesdetes esagcese sesahses sesaenaeeses aetulsenactesnecaereeesaes3 soo LO4, 187 ISIELACER « ‘isa a vb owaccbe yd anil Wewtecdaereeg sive dunWoahenvca vedas sdunscswaceaue Weve dadeasmnepecees 187i, PULLER (inn cans seeunsshotestaen oreccls eoeteeeeaneee 198, 184, 187, 189, aah 194, 200, 206, 272 phlex ‘var. donticulatar. id. ceigscs sens cethasedbatsloaacocesucceemonarsa eeeee oe eee SaBic 194 pulex var. Lonpispinaiiv.. <<. ics decsveavess dacescdodddevecste coddeddeceasaabocn@aaede evar oaeaee 199 PUleXAVvaL. NASUHUS 3s. d..wossssdeceee cecwedeeeceeenme cee ces ee ec HeM OR bile eveee 194 (35) Pialex war: PuUlicar dies ico. sFiccelapscavonds sevendsercsdedsvaetemaeeens Roomnse ces seasetasene 194 quadraneulaaies-ccasaceeeeecers seusaedesbescsostarase¥etemescotrasraseaney caveat wentarsasee: meieme 172 TECULTOSLTIS) wes seeb ene esbocece sarees SewiswsisconcuaedcesO Gorden tone Den Gueee ecvenreeu Rou cene es seoeeel 63 reticulata ...............+. Piacoa tS alow a paewecdoes Ueeseeencct heuer sueenetetsaeemeMer ster 170, 172, 206 TELLOCULVA: wiht ence dave sovoadevacs Séevedenecesces Saviked dcedeeceateroccnst seaseae sone nce cena: 203, 204 TONGA ss vecsasaceudshees sewestes sueceome tas Wasa Seppe ceoue pubes vel cesertsceuecnen 200, 199, 201, 214 | TOLUNGGE ccenocaeeasaces setacsibe ondccsondecseenadensecss tes ates tauad vente vecatenneees acai te oeeenaaman 169 POLONADEAL., ca.0.0s «oti -esesnsedessovaccoscadetheuge svandectans anumata corse hteete eaten neem 173 PUGS! os .decccedage sieeve needs ceeboadnusyecce eadeen tance eset as Sete aeent picereiae rata een tence aaa 205 BAPSUL 0.2 olvs Sccle soe tocecasoancccdes lease dgeveetcecoreupsedecoedty bacec ote atseceuiteteicass aermeae 198 BEMPCH EEL we) ca cnscactegasevecsueestssaudeavevdtesatinesnemteee ts 187 (51), 182, 183, 191, 204-206 SCHOCHILOTE 5.4 05.cc.decesgosuscdorascherscnidejueeestonvassestives cotisarometerccnese tee aaaceeene marae 198 BEVLU AGA oi 32 ses Levcssceewencdoesgd otiskasedsvaree, sogecedeetaeteccsan cece nct: hadaecceeeenas 179, 192 SUE Aarscawevssitce hececseeaakevencevusdseeseaseooareeee SWedad cous Uaccpeencer ec acwenteceaececstae 144, 178 Crt ee ean enn DMO hlanmee hs) " ROR Ondo REE) 2.04 (35, 51), 205 PHOTOG io osia.d 1 as aahatedsnccvesncual aadadssdatdl cadens Syba de ukeabes nar ratte Meret anne teat eemmane 197 PVETIBEICOSS 1.4 vijclrossvoaieusessicaue scoters tess ocuidelc tages cohen censor comnercemeaneen Joovearcaeelatneee 195 VOUMI Aes cerscdscnaedessdvanscasedsaccddeansasettcaseseaeen snandscce ccc raacaadmcnsMcd apstee eee itan aaetenae 178 WALTER, cee hststiedoasde sasdeosesstates acesancsdeasestewotessece’ ESCM Sete: (35), 196, 203, 204, 206 yD 1 101 C1 Paap ay eo 152, 142, 146, 160, 161, 210, 215, 216, 218, 224, 271 Circulatory ssystem Of... .221isi.2s6 ade castes voauecveacscscsuascapatas celdeesuemes 152-160 (51) | Da MOIMESS 3.2.00. .cccctecsacdesscicvcuacsctesnesadptaks luton sou chsmessssiec-syeesntet eae aie ena 142 DE WNT oo os. 03s ceaedscabanianecapbacuse swoxaensllevsen de caaantny tot panne cutest aashay hee 336 TIN PLOVISA 5. ovearves svete cceersesee che cles poutecetss veut ensdereknorsaevapecoceton ibeaeanse 336 (81) SPEVENSONL 5.5.4: iecwesseccosvoccsmocceccsescoccaacasuopestesavene sumer ssatna mmescniaeekie: Waeea eames 337 DAT WITKTIGS. «05.5 vcsegsaccedescrcaseck oan sescaseunUersonaspeesuemepsarycnave geet anuaine 335, 294 Development of Cyclops, 122; of Cypris herricki, 326; ot Daphnia............ 182 Dia phanosoma brandtianwM. s.iccccc caddevaeaeieies 7'7 (8) longicornis var. leptopus ............ccscecsrereeees aoatslecisnastacnatinena sn dcacie ren deeeaeer cae 64 MMM Neen an es dvips den tacsk «okies sus DburnceKee avgesneass combed tabwivadantthaccusasce aeaieine (10) PRR NER ane Cag ca tiees anche pak uaen seuiceel aa ata canth obuasants sedeunetemanemedean 71 (13) MMAR SEA acti coay et ebacs tees acts s%slekis cays abanfchelsspedbundebauneesaasy,scdoadvestesey 59 (8), 60 PUNO AME adic ceiase dn ran posves va lacebestadesiceneat cal Canons chayee hs se aualaey nrg to aassd thatp sedis cetorwaspahevessyeunas 81 (10) Heterogenesis in Cyclops............scscsecsrseeccneeeeasenseescrssseeessneeeesesneneseseseeeans 122 MAGIO COI 20. oon os poset ice cwccccee event ecsceracnesipcesecagnesson vencocaneedees 151, 143, 146 PHOLO PS GIA. ............00. 0.0 cesccseeceseeeteverccccrsccnsecesvacscsansessecseesces saceeeces 151, 161 GUDMSRUNES fobs ic iia3. seo ccacsoenene foes canssosanseccondsvecescerccsescosesnded soccnmnee 151 (35) TehthyOpHor pia. .................cecceeensenesecneenecentssnoeseccaccaeuevcossases soscasaessuaescees 86 PIG OCEY DUNS coos is ..00n seecesensaccneness 220, 143, 210, 211, 224, 233, 237, 265, 266, 273 GE TIROMB Ee ettatanin ds ssccec ar Weeicee tiene 294 MADMAN TE cosa y8 rainciada Geason see scadss as Ubdtiwesnveekae's tapsiwasenieps 238, 143, 210, 237, 248, 274 ALATA OCETEOIMI EN otecuedincroccostalaedocbee cece bedcatocie es seh seeecaeemacuteans sae aaeeke 234, 235 ARTE LTS sete eae Meee ec eoebrae ct iatscsitands s anc cscintuo descent diac aeigtneseteg dceracee te ves 235 (66) GQUAGTANSUIATIS, (.5.0052 0.00, cos> snnbece senccodvsrenonevoanae sae cnscuaseserndes 234 (59, 60), 274 SU RTN IRE eon coca ee oss eeawas ia supiealtesieaeci ae vsah Goncee ch tceevashastnoe mpeg sanes teasems (48) RERUNE TROVE AULD BNURS oo sece coer ae ca cece nak cercadetatenebanecsntescbecncetesceeadostabsecrartenroes 48, 47 MEEMAOT UB LAIE SE oe sade cyan ts av iae ole dou Gaopensesgianaces an Re cwneradednibinss texas Pane ee esc, 49 (1) WILACRHTUS VAL pAUCUUS.. :2 coup ac «he oh so cinns ov ce woaccosenesaarns degeecsenes nesses ae scnessstaeeNareep 49 RUF GTIG TR oat thee oo aide bck ae avo waa e Sack cee see beeite teraSceaes Mase ls sus esent notgeeieneatssmeapeatets 49 EWEN NAME PEIGN TM oe aes |e sot che aise Jak baie toss es 0's gap drs gent eaRabvapaney glib Gr veaax dn 148, 143, 161 MEISIRLOS Acne cael det tire die cc ideta nat cm weconn ae Siteeme 251 OXIPUWUS ges ccs ada sceodeoe secede savidustetcnceestecsuone etesene seetaemaiiaed 259 EPATIGVOTS UG nic fechas cd hoes ds oes oieige welay Has baie ae ssey = vinvelneD device sonia eee es «35s aaee eee ss eee 253 : SEIPOMEMOS, 500, sack venia dens voscesnandcutvoe see cetsnesduasnesseaadiwassuarasas 255, 256, 258, 259 EEUNCHbA oe s00 nes haccvesces aease W icepebedcdete deans sbapedecle dpe eseats metas ets cece: a ete 258 ETUVICAETISG go ccs: rosy codewceeae ecu dena badd peste wets en neaeee caesar eee en ante cena ae eet 258, 260 ; TUN CIN AGUS. 50d sneds oabaig (qa seat sucha c cease seeseddeieacoaes me enleneceektetnsls a rat ' 2 4? i f HAL