atith H a ir Sioa whore tecpee veneer eees eset SEESo SEROTS 2: Soccer Se tety ete eae e ees a ceqeayonmemestue edoataraey oan Ss ianatieasdteeteddan ~ aS — 7 3 Si gas = ~ a ee tereces sr in = = : . SS poe Goa —- en — 2 Fe aonyeelorerv lew sje ona 1tt9 SPE PGES PSS TEL bE Htighe SH Adi ia mah 1389 3 a} fit. 7 SoS SSS Moe 3, 1595. SON cee. oe ing = | SS = Get oe | Pad ot SD Bye Be Een. Sar ea | Nay Wor aes j 4% as c Cuick. On. ish my oS Dra ( ceoLocicat AND NATURAL HISTORY SURVEY OF MINNESOTA x HENRY F. NACHTRIEB State Zoologist _ - : 4 Bec REPORT TATE ZOOLOGIST / SYNOPSIS” ENTOMOSTRACA ‘MINNESOTA ios Fa NovemseER 1895 4 SAINT PAUL MINNESOTA ie O10 CL SERIES, No.2 ST. PAUL MINN.:! THE PIONEER PRESS COMPAN 1895 re? be cei ae - ; } : ’ f / \ DD ' i ; eek eat CONTENTS I oer. 5 5. Nas ccs oon 50's cena teamneneteeadds Hess liise sedeaceiidesedos sees rlesccedoce i RUN CRERTCATES Petes osc 5 A sis 5's 5 v4.0 ss aie'e'c comeaieoweeeemaece roeuoe coe Uebeen atGesbcandesenteeots lii tack = 0. oa nos. a'ss conde BacMeaBifanisen ss svicaveracanasdadaloce svete ¢s vi ENMU THIET AD Cer 25.0.. 55 = Jaliesiaas o0ue vdeotocccunperaee Neseaetecewee gee telge ste tect seas aeete vii EIN sc csan~ 528 0. \-0 050 s0ucesvne tameeadtcedtNar sulcte was addadgoewoad sstpscest3e vili Report of the State Zoologist for 1893 and 1894............ssseeescessseceeeeseeseeeeereees ix Synopsis of the Entomostraca of Minnesota..........ccssseesseseeeeesseeeescesseesessneesnene 1 RE EM Fe AM, 8, OM va ba nie ic odode gsie dete taWaceea pes ateckecte'esddesccececsccceeses 3 ee oo Echo cc ecissocsbeseensaaen nonueuiecstedsrtncaies sastoeceseedeeaces 5 Preface to the report of 1884..............-.sseeee coeceeees SN Se Re Og ea eT CE PPE 7 BUDO STAPDY....--.-..0...se.ccceeseeeceeescecceesrene ersceesececenensecanssensessesstssesenaaencasees 9 aeRO OTFA Part I..)........00cc0cc0-scencenssevovorscusa-scceccesee Pen shee SLIME A 39 Family Calami2®..................ccccecceseesenenessnenenencoveseeecwascesaersesensseseseees 46 eee LRH OGESIPAIN US; 4. cc sccoes ancseccecnacebcteccedeckitediapeccs.csemsd~esssntenebans 48 MDI ERE RHIMCENA. ccc Biac ««- chp -Semeecane tone 228 Genus ALONOPSIS. ...:scsecscscos sgevevocesc hunks «deleepnaspane <> ie .aiees ieee aoe 231 66 SLY DIGIA .. v.cccsecescescevstebecceseacccthh ccsscandceBs «sal. .ieeye a= aman 233 6 SGRAPTOLEBEBRIS ...2...cccewssssecesccubs -oebeess cc sees 2 es eeneesan tee ann 235 SS. 4 DUNHEVIDIA.......cssssccccckedecespeseae- ecbebeve=cenentie -apeaeesa oan 236 SMV NCHUS..... 5 iscestsenceoe dae en Pe Btn ee 237 Sub-wenus ALONA...:.2.00c. occu epee enases cates ceeeease scence Seaowen Ro ara 238 Section A, ALONA «........s:sccusecsnccsams -bapathey Sas -+sacamecnnaen soetaens amma 238 Section ‘B; ALONELLA.. j..::sccschusdoe Se - cavibe ss shas she uieeaneeaewanses so peeenaame 249 Sub-genus PLEUROXUS ... ...-)..cccsccnosrs@h «nekpbecs sf. csaaumucOescdens teietee Sesame 253 Section A, PLEUROXUS (Verus):.....2. <.c...2s..2.ccatecscoeneestesseese saunas 253 Section. B), LEPTORH-YNCHUS: fesse.) awensesscehecseqeseees cescces ane=be=aaneeee 260 Genus CHYDORDS:.«..........0cccsnsacects adel - qaeinenweapue seedem ete meraee aimee RRR RE He eT EEE HHH EE EEE SRE EE EET EHEE EEE HEE EEE SET THR eee HHH H EH EH EEE HOE EEE EEE EE HEE EH ee PRET H Team ws HEE HEHE EET R EEE Ee ee bus Noropromas. 5 oe IRIs Jp CYPRINOTUS........ Ae es Se ee SO EEE OAD SRE EPEE PNSUV IPMN ELL GL ORS . fee. 2. oc petoecaeeteaa censors oven sen oeeh co ack paiew det eaPs cape fo 321. CORRIGENDA. In the ‘‘key,’’ thirteenth line from top, read tyrrelli for tyrelli. Seventh line from top, read Herrick for He rick. Second line from bottom, read americanus for Amertcanus. Under Cyclops pulchellus, supply Plates XXVII, Figs. 4, 5; XXVIII, Figs. 5-8. Middle of page, read m. q. fuscus for m. g. fusens. Twelfth line from top, read Cyclopina gracilis for Cyclopsina gracilis. Fourteenth line from top, read lascivus for lascions. Fourth line from bottom, read Copepoda for Copepode. Second line from top, read Cladocera for Cladocere. The last three page numbers of the ‘‘key,’’ and the last within the brackets, should read respectively 132, 134, 134, 135. Third line from top, read Sididzx for Sidide. Third line from bottom, read Sida brachyura for Sida branchyura. Transfer the plate reference under Latona to Latona setifera. Under Ceriodaphnia cornuta, supply Plate LXVI, Figs. 4, 5. Middle of page, read Rhypophilus for Ripophilus. Eighth line from bottom, read D. kalbergensis for D. kahlbergensis. Middle of page, read cederstrcemii for coederstrcemii. ‘Thirteenth line from bottom, read D. schexfferi for D. sczehfferi. Near middle of page, read Macrothrix (2) pauper for Macrothrix (?) pauper. Read Acantholeberis curvirostris for Ancantholeberis curvi- rostris. Eleventh line from bottom, read Alona elongata for Alono elongata. Star Pleuroxus stramineus. Under Pleuroxus procurvus, add LXV, Figs. 6, 7. Under-Leptorhynechus falcatus, supply Plate LXII, Fig. 17. Under Polyphemus pediculus, read LIX for LXIX. Read Daphnia longiremis for Daphnia longiremus. Read Ilyocryptus longiremis for Hyoeryptus longiremus. Read Leydigia quadrangularis Leydig for Leydigia quadrangu- laris Leydig. Read Dunhevidia setiger for Dunhevidia Setiger. Fourth Jine from top, read adductor for abductor. Read Candona peircei for Candona Peireei. Read Cypria opthalmica (Jurine) for Cypria opthalmica Jurine. Tenth line from top, read Cypris gibberula for Cypris qibberala. Unexplained remain, Plates XXV, Fig. 15; LVII, Fig. 9; LXI, Fig. 5a; LXV, Fig. 9, and a few unnumbered figures. A number of the plate references were supplied from the explanations of plates: A few species are noticed only in the index and the plates. I am indebted to Professors Birge and Marsh for deciding between the conflicting spellings of names in the manuscript that were not observed until the index was pre- pared in most cases from the final forms. I embrace this opportunity to acknowledge the courtesy and good nature of the officers connected with the manufacturing department of the Pioneer Press Company, particularly of Mr. George R. Morrissey. By, aN. LETTER OF TRANSMITTAL. THE UNIVERSITY OF MINNESOTA, - MINNEAPOLIS, MINN., November 30, 1894. ent of the Board of Regents of the University of Minnesota. have the honor herewith to submit to the honorable Board ents my second report as zoologist of the Geological and Sona Survey of ‘ei aee cee with a report on the y a H. Turner, professor of Natural Science at Clark Uni-- ic Ga. These gentlemen have given their services to vey without charge, having asked for and received barely 1 to cover their expenses. Sie Very respectfully, your obedient servant, : HENRY F.. NACHTRIEB, State. Zoologist. BOARD OF REGENTS OF THE UNIVERSITY: OF “MUN NE SOTZs The State Superintendent of Public Instruction. The Hon..JOHN ‘S:; PILLSBURY, Presidemt.ccccs.cere. «sts adee~<. sos sannaincense Minneapolis. The HON. GREENLEAF CLARK, M. ‘A... 0ioceic Acteeedes. Jacctednces.cuea teeee see fuss aac nanan The “HON. CuSHMAN K. DAVIS, M: A¥s..2.Ac.ctcdece-) «-Ukescecel.: canbe eeeeeaaaennean St. Paul. - The Hon. STEPHEN MAHONEY, (M.A. (222k. ie Geacdes so Secons teens «ee eres Minneapolis. The HON: WILLIAM LIGGETT: ....5...cicccseadcecsesbecceae wcbbeaces man, G. J. 747, 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. 748, 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. Ba Anderson, John. E ee 1762. 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. Soc. Edinb. Vol. 2, 1863, pp. 304-314.) 80. Beitrage zur Kenntniss der Tiefseefauna der Schweizerseen. Zool. Anzeiger. Jahrg. 3, No. 51, pp. 130-134 and No. 54, pp. 200-207. "79, Balenophilus unisetus nov. Gen. et Sp. Ett Bidrag till Kannedomen om Harpacticidernas Utvecklingshistoria och Systematik. (4 pl., 26 pp.) Akad. Afhandl. Stockholm, Central-Tryck. 8°. Be —*79*, Ona New Genusand Species of Harpacticida. (Baleenophilus unisetus. 4 pl., % _ 16 pp.) _ Bihang till K. Svenska Vet. Akad. Handl. Vol. 5, No. 18. rd, W. j E a 84. List of Entomostraca found in Berwickshire. Trans. Berwick. Nat. Field Club. Vol. 1. “187, The Natural History of British Entomostraca. Mag. Zool. and Bot. Vol. 1, pp. 35-41, 309 333 (3 pl.), 514-526. 738), Id. Ann. Nat. Hist. Vol. 1, pp. 245-257. 7, 7 48. Id. Ann. and Mag. Nat. Hist. Vol. 11, pp. 81-95 (2 pl.) ae as 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. Trans. Berwick. Nat. Field Club. Vol. 2. ‘50. The Natural History of the British Entomostraca. (36 pl. VIII., 364 pp.) Ray Society, London. ‘59, Description of several species of Entomostracous Crustacea from Jerusalem. (2 pl.) Ann. and Mag. Nat. Hist. Ser. 3, Vol. 4, pp. 280-283. Balbiani, G. ’69. Observations relatives A une Note récente de M. Gerbe, sur la Constitution et le Développement de |’ceuf ovarien des Sacculines. Compt. Rend. de |’ Acad. des Se. Paris. T. 68, pp. 615-618. °69.1 Sur la Constitution et le Mode de Formation de l’ceuf des Sacculines. Ibid. T. 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 41’ étude de la Faune des eaux douces des Acores. 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. Soe. London. Vol. 3. Beneden, Edouard van. ’69. Sur le Mode de Formation de l’cenf 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 l’ceuf et de l’Embryon des Sacculines (Sacculina carcini Thomps.). (1 pl.) Bull. de l’Acad. Roy. de Belgique. Ser. 2, T. 29, pp. 99-112. ‘70... Reponse 4 quelques-unes des Observations de M. Balbiani sur l’ceuf des Sac- culines. Compt. Rend. de l’Acad. des Se. Paris. T. 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. Sciene. Nat.-Zool. Ser. 3, T. 16, pp. 71-131. ’61, Recherches sur les Crustacés du littoralde 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. ]’Acad. de Bruxelles. Tome 33. ] Ve: > oy .. “4 a ! 7a~ Se AV 4 See ENTOMOSTRACA OF MINNESOTA. aD | f (2 pl.) ‘Trans. Wisconsin eat Sciences, Arts and Letters. Vol. 4, pp. 77-112. a ° 1 & na ° B 5@ =F Qu ° is) @ bed = oy 394, 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. _ °§9, Tvende nye parasitiske Krebsdyr. Forhandlinger. oy 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. ha Om Sildeaat. Tidskrift for Fiskeri I. 1876, and Archiv f. Naturgesch. ; XXXIV. 1868. ii 78. Nye Slaegter og Arter af Saltvands-Copepoder. Forhandl. Vidensk. Selsk. Christiania. (Aar 1872.) XIV, pp. 35-60. Bourne,G.C. ig hag 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. I es. George Stewardson. - °64, On the Zoology of the Hylton Dene. _ Trans. Tyneside Nat. Hist. Club. Vol. 6. x 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. 968, On the Crustacean Fauna of the Salt Marshes of Northumberland and Dur- ‘ ham. (2 pl.) Ibid. Vol. 3, pt. 1 (1869), pp. 120-136. : 69, Description of an Entomostracan inhabiting a Coal Mine. (Canthocamptus _eryptorum. (1 pl.) Quart. Journ. Microsc. Se. New Ser. Vol. 9, pp. 23-24. 203-205. °72, A list of the non-parasitic Copepoda of the Northeast coast of England. foes. (5 pl.) Ibid. Vol. 4, pt. 2, pp. 423-445. Also in: Ann. and Mag. Nat. Hist. Ser. 4, meee Vol. 10, pp. 1-17. (5 pl.) _ %§, Monograph of the free and semi-parasitic Copepoda of the British Islands. 3 Vols. _ Ray Soc. London. 180, Copepoda. Exploration of the Faroe Channel by Staff-Commander Tizard _ R.N. and John Murray. Proc. Roy. Soc. Edinb. Vol. 2. 12 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. °83. Report on the Copepoda obtained by H. M. S. Challenger during the years 1873 76. (55 pl.) Rep. Scientif. Results Voyage Challenger. Zool. Vol. 8, No. 23. 142 pp. *86. Notes on Entomostraca collected by Mr. A. Halyin Ceylon. (4 pl.) Journ Jann. Soe. London. Zool. Vol. 19, No. 114, pp. 293-317. *88 Description of a new species of Cyclops. Sixth Annual Rep. Fishery Board of Scotland. 91. Revision of British species of Freshwater Cyclopidz and Calanide. Nat. Hist. Trans. Northumb. and Durham and Newcastle. 68-120. Also separate. London, 1891. 8°. Brady, G. §., and David Robertson. "73. Contributions to the study of Entomostraca. taken in the West of Ireland. VEE Ann. and Mag. Nat. Hist. Vol. 11, pt. 1, pp. 55 pp. 14 pl. On Marine Copepoda Ser. 4, Vol. 12, pp. 126-142. °76. Report on Dredging off the Coast of Durham and North Yorkshire in 1874. Rep. 45th Meet. Brit. Assoc. Advanc. Sc. in 1875, pp. 185-199. Brandt, J. F. *50. Ueber eine Abhandlung des Herrn Dr. Seb. Fischer, betitelt: Erganzungen, Berichtigungen und Fortsetzung zur Abhandlung tiber die in der Umgegend von St. Petersburg vorkommenden Crustaceen aus der Ordnung der Branchio- poden und Entomostraken. Ball. phys. math. de l’Acad. de St. Petersbg. T. 8, pp. 269-271. Brauer, Friedrich. 72. Beitrage zur Kenntniss der Phyllopoden. (1 pl.) Sitzangsber. d. kais. Akad. d. Wiss. Wien. Math.-naturwiss. Cl. Bd. 65, Abth. 1, pp. 279-291. Wien, 1872. 8°. 13 pp. 74, Vorlaufige Mittheilungen iiber die Entwicklung und Lebensweise des Lepi- durus productus Bose. Ibid Bd. 69, Abth. 1, pp. 130-141. Also separate. ‘77. + Beitrage zur Kenntniss der Phyllopoden. Ibid. Bd. 75, Abth. 1, pp. 533-614. Braun, M. (8 pl.) Also separate. Wien, 1877. 8°. *84. Physicalische und biologische Untersuchungen im westlichen Theile des fin- nischen Meerbusens. (1 Karte.) Arch. f. d. Naturkde. Liv., Ehst-u. Kurlands. Naturforsch. Gesellsch. Dorpat. Ser. 2, Bd. 20, Lief. 1. 1884. 8°. Brebisson, L. Alphonse de. Also in 130 pp. 25, Catalogue methodique des Crustacés terrestres, fluviatiles et marins, recue- illes dans le départment du Calvados. Mem. de la Société Linnéene da Calvados. 1825. Pp. 254-274. } Buchholz, R. "74. Crustaceen (15 pl.) In: Die 2. deutsche Nordpolarfahrt. 2 pp. 262-399. Burgersdyk. 2 Bd., 1874, °57. Land en Zoetwater-Schaaldieren. van Neederland. 1. Herkolts Bomostaffen voor eene Fauna : fi Nae 6. ue oak ENTOMOSTRACA OF MINNESOTA. 13 (Burgersdijk, L. A. J.) 3 61, Over inlandische soorten van Entomostraca. (Over insekten nit de omstreken Be van Breda en zoet-water Entomostraca. Tijdschr. v. Enotomol. Deel IV. RS 1861. Pp. 20-22.) r Cajander, A. H. 69. Bidrag till Kannedomen om sydvestra Finnlands Krustaceer. ‘ Notis. Sallsk. pro Fauna et Flora Fennic. Forhandl. Haft 10, pp. 371-376. ; Cann, E. ‘ 88, Les Copépodes libres marins du Boulonnais. " Bull. Scient. de la France et de la Belgique. Ser. 3, T. 1, Nos. 1-3, pp. 78-106. Car, Lazar. 2s 84, Ein Beitrag zur Copepoden-Fauna des adriatischen Meeres. (1 pl.) a Archiv. f. Naturgesch. Jahrg. 50, Bd. 1, pp. 237-257. _-Caruccio, A. , % 85. Zoologia in Viaggia di circeumnavigazione della R. corvetta ‘‘Caraciolo’’ vegli Anni 1881-84. Vol. I. bis Chambers, V. T. t 81. Two new species of Entomostraca. (2 pl.) ‘ Journ. Cinn. Soc. Nat. Hist. Vol. 4, pp. 47-30. -Chyzer, Corn. 57. Bulapest vidékén eddig taldlt hejinezokrol. Magyarhoni természetbarat. ete Il. Fiiz Nyitra. 53. Ueber die Crustaceen fauna Ungarns. Verhandl. der k. k. zool.-bot. Gesellsch. in Wien. VIII, pp. 505-518. Claus, Carl. 57. Das Genus Cyclops und seine einheimische Arten. (3 pl.) Archiv. f. Naturgesch. Jahrg. 23, Bd. 1, pp. 1-40. fe = * on th a tu ‘571. Weitere Mittheilungen tiber d. einheimischen Cyclopiden. (1 pl.) Ibid. Jahrg. 23, Bd. 1, pp. 205-210. 2 J 58. Beitrige zur Anat. u. Entw. d. Cyclopiden. Weigmanns Archiv. e : 1581. Zur Anatomie und Entwickelungsgeschichte der Copepoden. (3 pl.) a Arch. f. Naturgesch. Jahrg. 24, Bd. 1, pp. 1-76. * 1582. Ueber den Bau und die Entwickelung einiger parasitischer Crustaceen. (2 pl.) : Cassel, Fischer. 4°. 34 pp. 759. Ueber das Auge der Sapphirinen und Poniellen. Illustrations.) Miillers Archiv. (Reichert u. Du Bois-Reymond’s Archiv. f. Anat. 1859. pp. 269-274. ) 60. Beitrige zur Kenntniss der Entomostraken. 1 Heft. (4 pl.) Marbourg. 4°: 28 pp. 62. Untersuchungen iiber die Organisation und Verwandtshaft der Copepoden. (Im Auszuge zusammengestellt. ) Wiirzburg. naturwiss. Zeitschr. Bd. 3, pp. 51-103. 162!. Ueber die morphologischen Beziehungen der Copepoden zu den verwandten Crustaceengruppen der Malacostraken, Phyllopoden, Cirripedien und Ostra- coden. Ibid. Bd. 3, pp. 159-167. 14 GEOL, AND NAT. HIST. SURVEY OF MINNESOTA. ’622. Ueber Evadne mediterranea n. sp. und polyphemoides. 4 Kt. (Illust.) Ibid. Bad. 3, pp. 238-246. °625. Ueber den Bau und die Entwicklung von Achtheres percarum. (2 pl.) Zeitschr. f. wiss. Zool. Bd. 11, Heft 3, pp. 287-308. 63. Die freilebenden Copepoden mit besonderer Berticksichtigung der Fauna Deutschlands, der Nordsee und des Mittelmeeres. (37 pl.) Leipzig, Engelmann. 4°. X, 230 pp. 65. Zur niheren Kenntniss der Jugendformen von Cypris ovum. (2 pl.) Zeitschr. f. wiss. Zool. Bd. 14, Heft 4, pp. 391-398. ’66. Die Copepoden-Fauna von Nizza. Ein Beitrag zur Charakteristik der For- men und deren Abdnderungen im Sinne Darwin’s. (5 pl.) (Suppl. Heftl der Schrift. d. Ges. z. Beford. d. gesammt. Naturwiss. z. Marburg. 4°. 34 pp.) °67. Uber den Entwicklungsmodus der Porcellana-Larven im Vergleiche zu den Larven von Pagurus. Sitzungsber. d. Gessell. z. Beford. d. gesammt. Naturwiss. Marburg. Pp. 12-16. 68. Beitrage zur Kenntniss der Ostracoden. I. Entwicklungsgeschichte yon Cypris. (2 pl.) Schriften d. Gesell. z. BefOrd. d. gesammt. Naturwiss. zu Marburg. 1872. Bd. 9, pp. 151-166. Also separate: Marburg, Elwertin Comm. 1868. 8°. 16 pp. ’69. Die Cypris-abnliche Larve (Puppe) der Cirripedien und ihre Verwandlung in das festsitzende Thier. Ein Beitrag zur Morphologie der Rankenttissler. (2 pl.) Ibid. Bd. 9. Suppl. 5. (4°. 17 pp.) ‘72. Zur Kenntniss des Bau’s und der Entwicklung von Apus und Branchipus. Nachrichten d. Kén. Gesell. Wiss. G6ttingen. Pp. 209-225. Also in: Zeitschr. ges. Naturwiss. Bd. 6. 73. Zur Kenntniss des Baues und der Entwicklung von Branchipus stagnalis und Apus cancriformis. (8 pl.) Abhdlgn. d. k. Gesell. d. Wiss. Gottingen. Bd. 18, pp. 93-140. Also separate: Gottingen, 1873. 4°. 44 pp. "75. Die Schalendrtise der Daphnien. (1 pl.) Zeitschr. f. wiss. Zool. Bd. 25, Heft 2, pp. 165-173. °75'. Neue Beitrage zur Kenntniss parasitischer Copepoden nebst Bemerkungen liber das System derselben. (3 pl.) Ibid. Bd. 25, Heft 4, pp. 327-360. Also separate: Leipzig, 1876. 8°. 34 pp. °76. Zur Kenntniss der Organisation und des feineren Baues der Daphniden und verwandter Cladoceren. (4 pl.) Ibid. Bd. 27, Heft 3, pp. 362-402. °76'. Untersuchungen zur Erforschung der Genealogischen Grundlage des Crusta- ceen-Systems. Ein Beitrag zur Descendenzlehre. (19 pl. & 25 wd. cts.) Wien, 1876. Imp. 4°. VIII, 114 pp. °77. Zar Kenntniss des Baues und der Organisation der Polyphemiden. (7 pl.) Denkschr. d. k. Akad. d. Wiss. Wien. Math.-Naturwiss. Cl. Bd. 37, Abth. 1, pp. 137-160. Also separate: Wien, 1877. 4°. 24 pp. Sr eae ain ia et Me te cae ENTOMOSTRACA OF MINNESOTA. 15 78. Anlass und Entstehung seiner eigenen Untersuchungen auf dem Daphniden- Gebiete. Sitzungsber. der k. k. zool.-botan. Gesellsch. in Wien. Bd. 28, pp. 6-16. De 81. Ueber die Gattungen Temora und Temorella ([n. g.] nebst den zugehorigen Poached & Arten). (2 pl.) a : Sitzber. d. k. k. Akad. d. Wiss. Wien. Bd. 83, Abth. 1, pp. 482-493. Also sep- \ arate. . . 811. Neue Beitrage zur Kenntniss der Copepoden unter besonderer Berticksicht- igung der Triester Fauna. (3 pl.) Arbeiten a. d. Zool. Inst. d. Univ. Wien. T. 3, Heft 3, pp. 313-333. Costa, Achille. ‘82. Rapports preliminare e sommario sulle ricerche zoologiche fatte in Sardegna durante la primavera del 1882. Rendic. Accad. Se. fis. e mat. Napoli. Vol. 21, pp. 189-201. °83. Notizie ed osservationi sulla Geo-Fauna Sarda (Memoria prima. Risultamento di Recerche fatte in Sardegna in Settembre 1881. Napoli, 1882. 4°. pp. 42). a Atti aticad. Napoli. Vol. 1. (Atti R. Accad. Se. fis. e mat. Napoli. Vol. 9, ny No. 11. Pp. 41.) ‘Cragin, F. W. ' ; °83. A contribution to the history of the fresh-water copepoda. (4 pl.) Trans. Kansas Acad. Sc. Vol. 8, pp. 66-81. _ Czerniavski, V. 68. Materialia ad zoographiam ponticam comparatam. Daday, J. (Eug. von) 82. Ndatok Kolozsvar és kOrnyéke Crustacea-fauna-janak ismeretéhez. Orvos-természettud. Ertesit6. IV. k. 83. Adatok a Szent-Anna és Mohost6 faund-janak ismeretéhez. Orvos-természettud. Ertesit6. V. k. _ __-°831, Adatok a Retyézat tavai Crustacea-faun4janak ismeret¢éhez. Onna _ ‘Természetrajzi fiizetek VII. k. 84. Adatok a dévai vizek faundjdnak ismeretéhez. Orvostermeszettud. Ertesito. VI. k. *84', Catalogus Crustaceorum faunz Transylvaniz (, e collectione musei Transyl- vanici collegit et determinavit). Orvostermeszuttud. ErtesitO 6. Kot. Kolzsvar. (Ber. Siebenbiirg. Mus. Ver. Klausenburg. 1884. 27 pp.) 85, Uj allatfojok Budapest edesvizi faunajabol. Termezetrajzi {lizetek. 9. KOt. Budapest. ’851, Adatok a Balaton to faunajanak ismeretehez. M. tud. Akad. Term. tud. Ertesito. Budapest. oe 85°. Beitrage zur Kenntniss der Plattensee Fauna. et Math. Naturw. Ber. aus Ungarn. III. Budapest. 85°, Jelentesoz 1884ev nyaran Magyarorszag Kuloénb6zo videkein vegzett crusta- ceologiai kutatasok eredmenyerol. M. tud. Akad. Math.-term. tud. Kozlemenyek. 20 Kot. 3. > . rt, Lee ee ee - « , ¥ ) Pp > we . ache : _ gh o : 16 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. 85‘, Adatok Magyar-es Erdelyorszag nehany edesvizu medenczejenek nyilttu kri faunajahoz. Orvos-term tud Ertesito. 85°. Monographia Encopepodorum liberorum in Hungaria hucusque reperto- rum. A. M. tud. Akademia altal a Vitez-alapbol. 88. Crustacea Cladocera faunz 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. Fuzet. Vol. 13, Heft 4, pp. 114-143. Also: Ubersicht der Diaptomus-Arten Ungarns. (3 pl.) Ibid. Revue, pp. 177-180. Dahl, Friedr. 91. Untersuchungen tiber die Tierwelt der Unterelbe. 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 Reipublice Foederatz duce, collectorum. 1847-48. Proceed. Am. Acad. Arts and Sciences. Vol. 1, pp. 149-155. 52, 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 prts. 1852, 53. 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 319-361. Also separate: New Haven, 1854. 8°. 56. A Review of the Classification of the Crustacea (with reference to certain principles of classification). Ibid. Ser. 2, Vol. 22, pp. 14-29. Also separate: New Haven, 1856. 8°. Desmarest, Ans. Gaetan. '25. Considérations générales sur la classe des Crustacés, et Description des espéces de ces animaux, qui vivent dans la mer sur les cdtes, ou dans les eaux douces de Ja 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- lendriise 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 faune profonde de: lacs de la Suisse. (Mem. cor. par la Soc. Helvét, d. Sc. Nat.) (63 pp.) Neue Denkschr. 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 miarkliga Crustaceer af ordningen cladocera, funna i Dalarne. Ofvers. K. Vetensk. Akad. F6rhandl. 18 Arg. 1861. Pp. 115-118. Ferussac, Daudebart de. 106. Mémoire sur deux nouvelles espéces d’ Entomostracés et d’ Hydrachnés. Paris, Ann. Mus. Hist. Nat. VII, pp. 212-218. ‘| Fischer, Seb. 749, Abhandlungen liber eine neue Daphnienart, Daphnia aurita und uber 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. 1511, Branchiopoden und Entomostraceen. In A. Th. v. Middendorffs Reise in den daussersten Norden und Osten Sibiriens wahrend der Jabre 1843 und 1844... . (etc.) Bd. 2, Th]. 1. Wirbellose Thiere: Annulaten. Echinodermen. In- secten. Krebse. Mollusken. Parasiten. (By various authors.) 32 pl., 516 pp. 512, Beitrage 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.) 152. Ueber die in der Umgebung von St. Petersburg vorkommenden Crustaceen aus der Ordnung der Branchiopoden und Entomostraceen. (10 pi.) Mem. pres. savants Acad. St. Petersbg. T. 6, 1851, pp. 159-198. 53, (Title and reference asin ’51?. T. 26, 1853, pt. 1, pp. 74-100.) (2 pl.) 54, Erganzungen, Berichtigangen 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. (1! pl.) Ibid. T. 7, pp. 127-167. Also separate: St. Petersburg, 1851. 4°. 39 pp. (11 pl.) 542, 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. Beitrige zur Kenntniss der Entomostraceen. (3 pl.) Abhandlgn. d. k. bayer. Akad. d. Wiss. II. Cl. Bd. 8, Abth. 3, pp. 647-682. Also separate: Miinchen, 1860. 4°. 38 pp. 6. List of Illinois Crustacea. cS’ Forbes, S. A. =~\ a Bull. Dl. 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, On some Lake Superior Entomostraca. (4 pl.) Rep. U. S. Com. Fish and Fisheries for 1887. Pp. 701-718. 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 Flathead 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 Vhistoire naturelle du lac Léman. ’78. Faunistische Studien in den Stisswasser-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 Siisswasserseen. Biol. Centralblatt. Bd. 2, No. 10, pp. 299-305. *85. 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. On 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. ‘72:, Die Krustenthiere Boehmens. (100 text-figures. ) Archiv. f. d. naturwiss. Landesdurchforsch. v. Boehmen. Bd. 2, Abth. 4, pp. 201-271. °73. Ueber die Crustaceenfauna der Witlingauer Teiche und iber weitere Unter- such. d. BOhmerwaldseen. Sitzungsber. d. k. bohm. Gesellsch. d. Wiss. Prag. Jahrg. 1873, pp. 33-47. 731, Zviréna jezerSumavskych. 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.-K6nigl. zoolog.-botan. Gesell. in Wien. XVI, pp. 5 57-52 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. iibersetzt mit Anmerkungen. Herausgegeben von Joh. Aug. Ephr. Goeze. Niimberg, 1778-1783. (Vol. VII, 1783.) ENTOMOSTRACA OF MINNESOTA. 19 Gegenbaur, C. 68. Mittheilungen tiber die Organisation von Phyllosoma und Sapphirina. (2 pl.) Miuller’s Archiy. 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 iiber die freilebenden Copepoden des Kieler Hafens. Zool. Anz. Jahrg. 4, No. 83 (May 16), pp. 254-258. 811. Die freilebenden Copepoden der Kieler Féhrde. (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. On 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-figures. ) 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 Siisswasser-Calaniden. (2 pl.) Promotionsschrift, Leipzig. 34 pp. | Gruber, Aug., und Aug. Weisman. *80. Usber einige neue oder unvollkommen gekannte Daphniden. (2 pl.) Ber. tib. d. Verh. d. naturf. Gesellsch. Freiburg i. B. Bd. 7, pp. 50-116. an 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. Se. Paris. T. 107, No. 1, pp. 47-50. Translated in Ann. and Mag. Nat. Hist. Ser. 6, Vol. 2, pp. 177-179. »881. Diagnoses de deux Diaptomus nouveaux d’ Algérie. Bull. Soe. Zool. France. T. 13, No. 6, pp. 160-162. »89. 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. ’89', Revision des Calanides d’eau douce. (5 pl.) Mem. de la Soc. Zool. de France. T. 2, pt. 1, pp. 53-181. ’892. Sur la faune des eaux douces du Greenland. Bull. Soc. Entom. Fr. (Compt. Rend. Ac. Se. Paris. T. 108, No. 12, pp. 630- 632.) 91, Sur quelques entomostracés d’eau douce de Madagascar. Bull. Soc. Zool. France. T. 16, No. 8, pp. 223-224. 792. 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. Se. 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. Se. Philad. Vol. 1, p. 184. ’431. Daphnia reticulata n. sp. Ibid. Vol. 1, p. 196. Haller, G. °79. Vorldufige 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. [Abstract in: Zool. Anzeiger. Jahrg. 8, No. 195 (18. Mai, 1885), pp. 301-302. ] Heller, Camil. ’70. Untersuchungen iiber die Crustaceen Tirols. Nat. Med. Berichte. Innsbruck. I, pp. 67-96. ENTOMOSTRACA OF MINNESOTA. au Hellich, B. 74. Ueber die Cladocerenfauna Bohmens. Sitzungsber. d. k. k. bohm. Gesellsch. der Wiss. Prag. Jahrg. 1874, pp. 205-220. "7. 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, ets.) (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. ’*64. 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 a I’ Aide desquels certains Crustacés Parasites assurent la Conservation de leur Espéce. Mém. prés. par divers Savants 4 |’ 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. Zur Entwickelungsgeschichte der Entomostraken. II. Zur Embryologie der treilebenden Copepoden. (2 pl.) Niederlaind. Archiv. f. Zool. Bd. 4, Heft 1, pp. 55-74. Hogan, Rev. A. R. ’°62. On Daphnia Schefferi. Rep. 3lst Meet. Brit. Assoc. Advance. Sc. in 1861. Notes and Abstracts, p. 146. _ Hudendorff, A. '76. Beitrag zur Kenntuiss der Siisswasser-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 Siisswasserbecken. Ibid. Jahrg. 7, No. 169 (9 Juni), pp. 321-327. 841. Resultate meiner Studien iiber die pelagische Fauna kleinerer und grOsserer Siisswasserbecken 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. °851. Ueber die ‘‘blassen Kolben’’ an den vorderen Antennen der Stisswasser- Calaniden. Zool. Anzeig. Jahrg. 8, No. 197 (15. Juni), 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 animalcules qui se trouvent dans les liquers pré- parées, ete. . . Avecun grand nombre de figures. 2 Tom. 4 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 la 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 |’ Académie des Sc., etc., de Toulouse. x 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. *H4-'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 Paphitis found in New South Wales. Roy. Soc. Papers Van Diemen’s Land. II, 1852-54, pp. 243-253. 55. On Australian Entomostracans. Papers and Proceedings of the Roy. Soc. of Van Diemen’s Land. III. (II, 1852- 54, pp. 253-262; ITI, 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 Siisswasserfauna 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. dela 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, 1845, pp. 283-345 and 453-688; Bd. 2, 1849, pp. 1-211) 366-446, 527-609.) 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 qul 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. Oa 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. 719, Entomostraca. Dict. Se. Nat. XIV. 23. Crustaceology. Edinburgh Encyclopedia. Ledermulier. 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 Travemiinder 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. wi \ 59. Bemerkungen iiber den Bau der Cyclopiden. (1 pl.) ps _~ Archiv. fiir Naturgesch. Jahrg. 25, pp. 194-207. ; eal 60. Naturgeschichte der Daphniden (Crustacea Cladocera). Mit 100 Kupferta- 2 ______-feln. 4°. Pp. IV, 252. Tiibingen. 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. 2sectiones. Lund, 1853. 8°. Pp. XVI, 222. 61. Beskrifning Gfver 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. *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 ]’ Europe. Bull. Soc. Zool. France. T. 13, No. 6, pp. 156-158. Lindstrom, G. 55. Bidrag till Kannedomen om OestersjOns 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 okaudt 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 anew genus of Calanidae (Labidocera). (1 pl.) Ann. and Mag. Nat. Hist. Ser. 2, Vol. 11, pp. 25-29. *53'. 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 |’ 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. 792. 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 Cyclopid and Calanidz 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. I, 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 iiste.;Crustaceen. Jahresber. d. Nat. Gesellsch. zu Hannover. 20, pp. 22-36. 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. Jahresb. 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 Fabrt 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 4 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. de la Soc. d’études sc. de Paris. *87°. Entomostracés et Hydrachnides recueillis par M. Dollfus. Feuille des jeuues naturalistes. Moniez, R., et Th. Barrois. *88. Matériaux pourservir a |’étude de la Faune des eaux douces des Acores. 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. ’°63'. 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 Danie et Norvegize reperit, descripsit et iconibus illustravit. Cum tabb. aen. XXI. 4 maj. Lip- size et Hafniz 1785. 1776. Zoologiz Danice prodromus, seu animalium Danie et Norvegie indigen- arum characteres, nomina et synonpyma 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 Danixz et Norvegie rariorum ac minus notorum descriptiones et historia; ad formam tabularum denuo edid. frater auctoris. IV Voll. Cum CLX tabb. Fol. Hafnize et Lipsize (1779-84) 1798-1806. (German and Latin text.) j 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. f Nicolet, Hercule. ‘49. Crustaceos y Aracnidos. In: Claud. Gay’s Historia fisica y politica de Chile ......... auspicies del supremo gobierno. Paris, 1814-54. 8° (Atlas in Fol.) Zoologia. T. III. 547 pp. Nordman, Alexander von. 32. Zweites Heft in: Mlkrographische Beitrage zur Naturgeschichte der wirbel- losen Thiere. 2 Hefte. 20 Kupfrtaf. 4°. Berlin. 64, Neue Beitrige zur Kenntniss parasitischer Copepoden. Erster Beitrag. (4 pl.) Bull. Soc. Impér. des Nat. Moscow. T. 37, P. 2, pp. 461-520. Nordquist, Osc. ae 86. Bidrag till Kannedomen om Crustacéfauna i nagra af mellersta Finlands sjOar. Acta Societatis pro fauna et flora fennica. T. 3, Ne.2. 26 pp. Helsingfors, 1886. 87. Bidrag till kinnedomen om Ladoga sjés crustacéfauna. 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 Lynceide. (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. "79, 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 rice:che 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 iiber 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 III. Genres Daphnia, Bosmina, Polyphe- mus, Cyclopsina, Ais WTR 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 MCC LR an Baird [affinis]. (1 pl.) Abhandl. d. Naturwiss. Vereins z. Bremen. 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’ Zin 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 nérdlichen Stillen Ocean und Behringsmeer gesammelten freilebenden Copepoder. (5 pl ) Archiv. f. Naturgesch. Jahrg. 50, Bd. 1, pp. 281-304. j ’84°, Ein neues Copepoden-Genus aus der Jade. {Huntemannia n. g., Jadensis D. 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 [Zacharie] 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 nouveiles du genre Diaptomus Westwood. Bull. Soc. Zool. France. T. 13, No. 6, pp. 159-160. ’89. Berichtigung zu Dr. O. E. Imhof’s Aufsatz. ‘‘ Fauna der Siisswasser-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 Berticksichtigung 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. Jahrg. 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. Se. Paris. T. 100, No. 83, pp. 919-921. Also: Ann. Mag. Nat. Hist. Ser. 5, Vol. 15, June. Pp. 498-499. ENTOMOSTRACA OF MINNESOTA. 3b1 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. 82. 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 aniwali viventi. Florenz. 1688. Auimaletti aquatici. Napoli. Rehberg, Herm. 80.’ Zwei neue Crustaceen aus einem Brunnen auf Helgoland. Zool. Anzeiger. Jahrg. 3, No. 58 (Juni 21), pp. 301-308. *80'. Beitrag zur Kenntniss der freilebenden Stisswasser-Copepoden. (1 pl.) Abhandlgn. naturwiss. Ver. Bremen. Bd. 6, Heft 3, pp. 533-554. *80*. Weitere Bemerkungen iiber die freilebenden Siisswasser-Copepoden. (I’igs.) 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. Soe. Zool. France. T. 12, pts. 3-4, pp. 156-164. 88. Entomostracés nouveaux ou peu connus. Ibid;-. TL: 13: *88'. Cladocéres et Copépodes non marins de la fauna de France. Rey. 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- tate: Paris. 13890. 8°. . ‘91. Recherches sur le systéme glandulaire et sur le systéme 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. l’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 tav. 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 iSommeren 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 Throndbjems 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. sididz a. kolopedidz). (4 pl.) Med Hs. Maj. Kongens Guldmedaille Prisbelomiet Afhandling. Christiania. AS WiLL app: 74, Omen 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 Verhiltniss der Artemia salina Milne Edw.zur Artemia Muhlhausenii 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 Ausseren 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. Beitrage 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). Hett 15, I. Teil. 93. Id. II. Teil: Harpacticide. (102 pp., 8 pl. and 2 text figs.) ipid= Heft 15; -II. Teil. Schneider, J. Sparre. °84. Unders6gelser 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 liber 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 AngehoOrigkeit der Daphniden. Berlin, 1877. 4°. 1pl. 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. 7 39. Beitrige 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. Beitrage zur Parthenogenesis der Arthropoden. (2 pl.) VI. Uber die par- thenogenetische Fortpflanzung bei Apus und verwandten Crustaceen. Leip- wig, 1871. 8°. VIII, 238 pp. 34 GEOL, AND NAT. HIST. SURVEY OF MINNESOTA. 73, Uber Parthenogenesis der Artemia salina. : Sitzungsber. d. Konigl. Akad. d. Wissensch. zu Miinchen. Bd. 3, pp. 168-196. " Smith, F. A. 61. Sur les Ephippies des Daphnies. (2 pl.) Noy. 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. Proc. Acad. Nat. Sc. Philadelphia. 1863. Pp. 138-142. Straus-Durckheim, Hercule Eugene. . 19-20. 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. (Zoea pattersonii). (1 pl.) Ibid. Vol. 2, pt. 2, pp. 114-120. Thallwitz, J. 90, Entomostraken [aus der Umgegend Dresdens]. V. 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. Development of 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 A1itemis and of Apus. Zoolog. Journ. V. Thorell, T. 59. Bidrag till Kannedomen om Krustaceer, som levfa i arteraf Slegter Ascidia, L. Till K. vet. akad. inlemnad d. 14 September. (Stokholm, Akad. Handl. III., 1859-60.) (In German in Zeitsch. f. d. ges. Naturwiss. Halle. Bd. 15, 1860, pp. 114-144.) Tilesius, W. G. _. °1§, De Cancris kamtschaticis, oniscis, entomostracis et cancellis marinis micro- scopis noctiluscentibus; (cum appendice de Acaris et Ricinis kamtschaticis. ) (4 pl.) ; Mém. de l’Acad. imp. des Sc. de St. Petersbourg. T. 5, pp. 331-405. (4 maj. Petropoli. 1812.) 14.19, Ueber das niichtliche 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 kandiesfélék. Cladocera. - Math. termtud. k6zlem. Kiadja a m. tud. Akad. I. k. 611. Die Rotatorien und Daphnien der Umgebung von Pest-Ofen. Verhandl. d. k. k. zool.-botan. Gesellsch. in Wien. XI. Pp. 183-184. 62. Pest-Budan 186i ben tald4lt Daphnidak. Mathem. term. tud. kG6zlem. Kiadjaa m. tud. Akad. II. k. Trybom, Fil. 81. Jakttagelser om det Jagre djurlifvet pa de platser utanfor Bohuslans kust, der sillfiske med drifgarn bedrefs vintern 1880-1881. Oefvers. Kgl. Vet. Akad. Férhdlg. Stockh. Arg. 38, No. 3, pp. 33-43. Turner, C. H. 92. Notes upon the Cladocera, Copepoda, Ostracoda and Rotifera of Cincinnati, with descriptions of New Species. (2 pl.) Bull. Scient. Laboratories of Denison University. Vol. 6, pt. 2. pp. 57-74. 193, 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. 1. System atic Portion. 2. Late Larval History of Cypris Herricki. 3. Ilyocryptus spinifer, Herrick, not the same as I. longiremis, Sars. (2 pls.) Bull. Se. Labs. Den. Univ. Vol. 8, pt. I, pp. 1-18. 3 36 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. ‘94. Notes on American Ostracoda, with Descriptions of New Species. (2 pl.) Ibid. Vol. 5, 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. Zooiogie I, pp. 330-338. Vejdovsky, Franz. ’°82. Thierische Organismen der Brunuenwasser 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 letude de Ja 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.) Jabreshefte 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 Historie 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 due eriincise. Roy. Fol. Lipsiz.) Walter, Alfred. ’°88. Transkaspische Binnencrustaceen. I. Entomostraca. (1 pl.) Zool. Jabrbiicher. Abth. f. System. Geog. u. Biol. d. Thiere. Bd. 3, Heft 6, pp. 987-1013. ENTOMOSTRACA OF MINNESOTA. 37 Weber, M. 76. Ueber die Nahrung der Alausa vulgaris und die Spermatophore von Temora velox Lilljeborg. Arch. f. Naturgesch. Jahrg. 42. Weisman, August. "74, Ueber Bau und Lebenserscheinungen von Leptodora hyalina Lilljebore. 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. 36. 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- else ; 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 tiber 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. 541. Monographie der Ostracoden. (6 pl.) Ibid. Jahrg. 20, Bd. 1, pp. 1-88. ~ ‘ - ~ ie me a +; 7. * _ ‘> ; bee Z. , 2 1 as oe »~ “, ve, ~ o rs . y pate ‘ t N a 4 ‘ vA ~ HERRICK / f Sioa Hel aed Be af a= i a See Oe 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 scav- 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 simuiate 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 aU 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 trouvent 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 perfeetly 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 one 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 iu 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, ete. In Wiegmann’s Archiv fiir Naturgeschichte, 1857. 2. Weitere Mittheilungen weber 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 Niederlandisches 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- i dae a a Alea aaa aa ca 7 3 on 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 ofits 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 d Kau 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 Aquatie 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 Oladoceran 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. Il. Cyclopide. Cephalothorax compact, ovoid; abdomen slender. Antenne usually shorter than the cephalothorax, both geniculate in the male, 8- to 18-jointed. Second antennz (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. Mavxille 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 ore 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- 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 CALANIDA. I. FIFTH FEET OF THE FEMALE BI-RAMOSE. a. Ioner 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 II. 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 prehensile appendages in the Male, 2. 22 e-em NS Ca een oT et ee b. First swimming foot with one-jointed inner ramus, the rest two- jointed. © a edt Rea eee Eurytemora, 49 ce. Swimming feet with three-jointed 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 de:cribed by the author. See plates. pote jes” 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. 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 charaec- ters, such as the following: Head distinet 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, antennz 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- illz and maxillipeds rather large. Fist 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, antennz 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, antennz reaching nearly to end of the abdomen. (Mediterranean.) Sp. 3. T. dubia Lubbock. (As iden- tified by Brady.) Exactly as in 7. 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, Ueher die Gattun- gen Temora und Temorelia, and Brady, Chalien- ger Copepoda. Eurytemora. Antenre 24-(25?) jointed, genicula- tion between joints 18 and 19. Max- il]z 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. velox (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- tennz more obvious. (Same localities aud rivers Rhine, Elbe, etc.) [See be- low on 7. 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. EE. 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. 51 * Eurytemora affinis Poppe. PLATES I, Fies. 5-10; LX, Fies. 8-15. Lilljeborg ’53 (Temora velox); Poppe ’80 (Temora affinis) ; Claus ’81 (Temora affinis) ; Giesbrecht ’81! (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; antennz 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 setz, 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 setze; 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 sete 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 sete and three spines; the second segment of the inner ramus of second and third feet bears six setz, its predecessor three, while the _ terminal segment of the outer ramus carries five sete, 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. or Ww 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 deteeted 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 dimorphous 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 TZ. 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 a long, 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 TZ. affinis only in three very significant particulars: first, the body is more slender; second, the caudal stylets are considerably longer; third, the a. 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, Fies. 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; fitth feet of female slender, alike; abdomen in male very slender, with short Stylets armed with five terminal sete and aseries 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. j 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 instill others Eucheta. 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. Cephalothorax composed of seven segments, of which the cephalie 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 seyv- eral long setie, inner ramus shorter and two-jointed. The mandibles armed with about nine acute teeth and provided with a bi-ramose . palp. The mavxille of the first pair are very short and armed with closely set setee. 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. Perhays 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 asort of heterogenesis 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 aaa on the last joint of the right anten- na. . . aSiaticus, 56; denticornis, 56. II. Male ith a ea mite on iaits antepenult segment of the right antenna. . . serriconis, 56; wierzejskii, 57; pectinicornis, o trybomi, 57; hircus, 5 III. Male with the appendage of the antepenult segment of the antenna prolonged into a curved hook longer than the penultimate seg- ment, —. . . . @iseni, 58; franciscanus, 58. IV. Male with the apeeddies of the aunieianalinenees 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. VY. 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 processupon therightside. . signicaudatus, 63; incongruens, 63; gibber, 63. 5. 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. + 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. +7 Inner ramus of the left fifth foot longer tban the basal joint of the outerramus. . . . ._ Siciloides, 69; novamexicanus, 70; an sanguineus, 71; minnetonka, 71; armatus, 72. 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; piscinz., 74; laciniatus, 74. ** Internal branch of the right fifth foot of the male two-jointed. . castor, 74; glacialis, 75; mirus, 75; sancti-patricii, 75. 6. Internal ramus of the right fifth foot of the male shorter than the basal joint of the outer ramus. * This internal ramus greatly expanded. . . . . . . Ililljeborgi, 76. ** Toner ramus of the right fifth foot of the male not enlarged.» t Abdomen asymmetrical. . . roubaui, 76; tyrelli, 76; theeli, 77; lobatus, 77; affinis, 77 amblyodon, 78; mississippiensis, 78. (D. birgei, 79.) a Diaptomus asiaticus Uljaniv. t PLATE X, Fie. 7. 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. et at, ae | Oe i = - . i. ie oo Yr ony? es et ‘ Diaptomus denticornis Wierzejski. : PLATE X, Fie. 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- tenne 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. ea. 2)" Diaptomus serricornis Lilljeborg. Puates VIII, Fre. 14; IX, Fie. 12. vd Lilljeborg °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. ° af as eT SR Me ee a a dy Si eae RE Pie ENTOMOSTRACA OF MINNESOTA. 57 Diaptomus wierzejskii Richard. PLATES VIII, Fie. 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. Theinternal 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, FIa. 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. Antenne 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; IX, 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 antenne almost reach the base of the stylets. The form of the feet may be gathered from the figures. Oregon. Diaptomus hireus Brady. PLATE XXXIII, Fias. 6-8. Brady ’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 antenne reach backwards as far as the posterior end of the thorax. Inner branch of 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. Mave.—Auntepenultimate 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, Fias. 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. Eisen. 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 antennz 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. PEATE WET Eke: 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 styliets 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 A¥a, 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 ’93. ‘‘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 antennz reach just beyond the fureca. 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 faleciform. 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. * Diaptomus sicilis Forbes. PLATES V, Fies. 1-7; XIII, Fie. 18. Herrick ’83 and ’34; 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 size 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 seginent 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, Fie. 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 weli distinguished from its allies. The antennz 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- tinetly 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 a spine. The outer ramus of the same foot is forcipate. Length 1.0 to 1.5 mm. * Diaptomus shoshone Forbes. PEATh Vo Pia iL: 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.’ ‘‘Hgg 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 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 iifth 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 antenne 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. ne Pay —" Sey * ‘ 75 ENTOMOSTRACA OF MINNESOTA. 63 * Diaptomus signicaudatus Lilljeborg. PLATES VIII, Fic. 13; 1X, 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, Fa. 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 64 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. the right side distally a broad blunt process. Antenne 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, Fic. 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 issomewhat longer than the basal joint of the outer ramus. At the base of the claw of the outer ramus isastrong tooth. The apicalsegment 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 long. 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 antennz 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. We do 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 1.4mm. Diaptomus tatricus Wierzejski. PLATE X, Fie. 8. Wierzejski ’82 (lacinulatus), and ’83; De Guerne and Richard ’89. A large, stout form, with antennz 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, Fie. 7. S. Fischer ’53 (Cyclopsina cceruleaj; 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 itis rather smaller and from which it 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 almostas long as the claw of the 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. Length 1.8 mm. ' ad ie 2 © 66 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. Diaptomus gracilis Sars. PLATE IX, Fie. 1. Sars ’64; Gruber ’78; Rehberg ’801; Daday ’85°; De Guerne and Richard ’89. This very widely distributed species is scarcely over 1.0 mm. long and very slender. The antenne are much longer than the whole body. The stylets are short, and the first segments of the abdomen are armed with strong spines. The thner rami of the fifth feet are one- jointed in both sexes, in the female shorter than the basal segment of the outer ramus. The apical joint of the outer ramus is well- developed and bears two spines, one of which is as long as the claw. The inner ramus of the right foot of the male is very long, reaching nearly to the base of the claw. There is a curious, conical, ciliated process from the inner aspect of the outer ramus of the left foot. Diaptomus orientalis Brady. PLATE X, Fie. 5. Brady ’86; De Guerne and Richard ’89. There seems to be some doubt whether the various collections from Ceylon and Australia really pertain to the same:species. The last thoracic segment is rounded and armed with short spines, as is the first abdominal. The second abdominal segment is very short. The caudal stylets are short, with long sete. The antennz reach the stylets. The antepenultimate segment of the male antenna bears a long hook. The terminal segment of the outer rami is distinct (not so figured by Sars), the inner ramus as long as the basal segment of the outer. Inner rami of male fifth feet very short and one-jointed. Length 1.3 mm. *Diaptomus stagnalis Forbes. PLATES III; XIII, Fras. 11, 13. Forbes ’82; Herrick ’82 (D. giganteus), and ’84; De Guerne and Richard ’89. This species was described by Professor Forbes and the writer at almost the same time, but as the former’s description appeared in a periodical it was more promptly distributed and deserves priority. A very large species, resembling D. castor, the place of which it takes in America. Greatest width in front of the middle. The an- tenn scarcely extend beyond the thorax. The first segment of the thorax is separated by a suture, as is the last, which is greatly pro- duced laterally and bears two spines. The first abdominal segment is much longer than the rest of the abdomen. The caudal stylets are very short and broad, divaricate, and ciliated externally. The caudal setee are large, short and profusely plumose. The egg sac is large and spherical. In the male the abdomen is slender and five-jointed. The five joints preceding the hinge of the right male antenna are very ENTOMOSTRACA OF MINNESOTA. 67 much thickened. The antepenultimate joint bears a small hook and the last two joints are relatively very small. The antennules are of the usual form, the two-jointed branch being much the shorter. The first feet of both sexes have, as usual, the inner ramus two-jointed. The external spines of the outer ramus are longer in the male. The fifth feet of the female have the inner ramus very long and two jointed, armed apically with two very long, setose, equal spines. The apical segment of the outer ramus is distinct and armed with two subequal spines, and is protected by a spine from the preceding joint near its base. The claw is strongly toothed and straight. The right foot of the male is much longer than the left and has a short toothed apical claw. The accessory spine is near the base of the claw. The inner ramus is very small and spatulate. The preceding segment bears a smulil spine externally and a lamellate appendage within. The inner ramus of the left foot is larger and nearly as long as the basal joint of the outer ramus; it is corrugate internally and bears a short spine apically. Opposite this ramus on the basal segment of the outer are small sete. The apical segment of the outer ramus bears two curved Spines and numerous set apically and a hairy plate internally. Length 3.0 to 4.0 mm. This species has been found in Minnesota, Illinois, Ohio, Kentucky and Alabama. . *Diaptomus albuquerquensis Sp. n. PLATES VI, Fras. 1-3; VII. Magnitudine mediocri, Cephalothorax latitudine maxima ad medium sita; seg- mento ultimo feminze ad latera extante, utrinque mucronibus 2 armati. Segmentum abdominale 1-mum partem reliquam abdominis, setis exceptis, longitudine superans, utringue mucrone distincto preditum; segmentum 2-dum per breve. Rami furcales segmento antecedente fere «quantes, intus ciliati. Antenne 1-mi paris extremam . farcam attingentes, vel superantes, 25-articulate. Articulus antepenutimus anten- nee prehensilis maris processu recto vel subanguiformi sat longo preeditus. Pes 5-ti paris feminz ramo exteriore triarticulato, articulo 3-tio perspicuo, et aculeo interiore circiter ad medium processus unguiformis articulo 2-di porrecto. Processus ungui- formis modicis arcuatus, dentibus ad partem medium armatus. Ramus ejus interior extra medium sed non ad finem articuli 1-mi rami exteriores porrectus, biarticulatus, et ad finem ciliatus. Pes dexter 5-ti paris apud marem ramus interior 1-articulatus, per breve, articuli antepenulti rami exterioris longitudinem quant. Unguis (vel segmentum 3-dum) per magnum, in longitudine pars reliyuis pedis superans. Pro- cessus lateralis segmenti 2-di magnus, ad basin intus dentibus minutibus affectus. Pedis sinisteri 5-ti paris apud marem, articulus ultimus rami exterioris conicus, in- tus lamina ciliatus instructus, ad apicem mucronibus duobus affectus. Segmentum 2-dum ejus ramus, intus granulosus. Ramus interior previs, uni articulatus. Ani- mal pleurumque pellucidum, colore albido.” Longitud. feminze 1.4-1.6 mm. This medium sized species occurs in the water reservoir supplying ° Albuquerque, New Mexico, together with D. novamexicanus in large numbers. The last segment of the thorax is protuberant and bears 5 68 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. two strong spines. The first segment of the abdomen is much longer than the entire remainder of the abdomen and bears a strong spine on either side anteriorly. The stylets are short and ciliated internally. The antenne reach to the end of the stylets. In the male the ante- penultimate segment bears a straight process directed distad and but slightly curved at the tip and shorter than the penultimate segment. The thickened portion of the geniculate antenna is very much modi- fied. The fifth foot of the female has an obscurely two-jointed inner ramus much shorter than the first joint of the outer ramus. The hook of the penultimate segment of the outer ramus is armed with a short series of sharp spines along the middle third of the inner aspect or rather nearer the base than the apex. There is a small spine at the base of the terminal segment, which is distinct and carries two long but unequal spines. The final joint or claw of the outer branch of right fifth foot of the male is very strong and gently curved, being longer than the whole leg. The accessory spine is also heavy and nearer the end than the base of the second segment, and is minutely denticulate near its base. The inner ramus of the right foot is one- jointed, very short, and slightly ciliate at the tip. The left leg reaches to the tip of the inner ramus of the right leg. Its terminal segment is of moderate size and ends in one immovable toothed spine and abristle; along itsinner aspect a ciliated lamina is situated. The preceding segment has a granulat area along its inner aspect. The inner ramus resembles that of the right leg. * Diaptomus lintoni Forbes. PLATE HIG: 12: Forbes ’89. “A large red species occurring commonly with D. shoshone, but distinguishable from it at a glance by its different shape, its longer antenn, its smaller size, and by characters derived from the right antenna and fifth foot of the male. The thorax is symmetrically ellip- tical in outline, broadest at the middle. The posterior angles are not produced nor bifid, but are each armed with a minute spine. The first segment of the abdomen of the female is not especially produced, but bears at its broadest part a minute spine on each side. The abdo- men itself is very short, its length contained about three and one-third times in that of the cephalothorax. The antenna of the female is long and slender, 25-jointed, reaching a little beyond the tip of the abdo- men. The fifth pair of legs in this sex is similar to those of D. sho- shone, but much smaller. The inner ramus is not jointed. It is longer than the basal joint of the outer ramus, bears two stout plumose sete at the tip, somewhat shorter than the ramus itself, and has also at its inner tip a patch of small spines or fine hairs. The second segment ENTOMOSTRACA OF MINNESOTA. 69 of the outer ramus with its terminal claw is two thirds as long again as the preceding segment, the breadth of the latter two-thirds its length, The third joint is indicated by a single long, stout seta and one or two smaller ones. “Tn the male the geniculate antenna is relatively rather slender, its last two joints without special appendages, its penultimate with a Slender transparent apical process, reaching about to the middle of the succeeding segment, acute at tip, but neither serrate nor emarginate. Fifth pair of legs in the male usually without internal ramus to the right leg, but this ramus sometimes represented by a Small rudiment. The limb is usually slender and its terminal claw short. The basal segment of the outer ramus is nearly as long as the adjacent segment of the pedicel, and the slender second segment of this ramus is fully as long. Long lateral spines borne near the tip of this segment. The terminal claw is about two-thirds as long as the Segment, is somewhat abruptly angulated near its base and slightly recurved at the tip. The inner:ramus of the left leg is very stout and long, reaching almost to the tip of the outer ramus, is slightly curved outwards, and has the apex minutely hairy. The basal segment of the outer ramus is thick, two-thirds as broad as long, somewhat inflated within, where it extends downwards beyond the articulation with the second segment as a rounded expansion covered with ex- tremely fine hairs. Second segment of this ramus longer than first, but only half as wide, bearing at its tip, within, a rather small, obliquely projecting cushion covered with cilia, and two stout terminal spines, one short, blunt, straight, and smooth, the other curved and plumose, its length about half of the segment to which it is attached.”’ Length 2.5 mm. * Diaptomus siciloides Lilljeborg. PLATE VIII, Fie. 10. De Guerne and Richard ’89. This species approaches D. sicilis Forbes and D. caroli Herrick very closely, and is said also to resemble D. gracilis Sars. From caroli it may be at once distinguished by reason of the fact that the third joint of the outer ramus of the fifth foot of the female is obsolescent. From the smaller form of D. sicilis it is scarcely possible to distinguish it. The spinous armature of the thorax and abdomen seems more marked, and the second segment of the abdomen is shorter in sici- loides and there is an appendage to the inner aspect of the basal joint of the outer ramus of the right leg. Last two segments of thorax con- fluent, bearing two lateral spines. First abdominal segment longer than the rest of the abdomen, laterally spined. Second segment very short. Caudal stylets once anda half as long as broad. Antenne somewhat exceeding the stylets. The antepenult joint of the right 70 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. male antenna bears a hook of moderate size. Fifth feet of female short, with a short stout claw and with the inner ramus as long as the basal joint of the outer, one-jointed. The apical joint of the outer ra- mus is obsolescent, bearing small spines. The male feet are almost exactly as in the small form of D. sicilis, but have a process on the basal segment of the outer ramus of the right leg. Length 1.3 mm. Lake Tulan, Fresno, Cal. * Diaptomus novamexicanus Sp. n. PLATE VI, Fias. 7-10. Inter minores sui generis, modice robustus. Cephalothorax latitudine maxima ante medium sita. Segmentum cephalothoracis ultimum lateribus utrinque mu- cronibus brevibus ornatum. Segmentum abdominale 1-mum utrinque mucrone brevi instructum. Segmentum 2-di per breve. Rami furcales segmentum antecedens longitudive sequantes, setis apicalibus brevibus. Antenne 1-mi paris femine retio circiter ad furcam vel interdum ad finem furce porrecte, articulis 25 composite. Articulus antepenultimus antennze dextre maris lamina, antice in processu ungui- fore, apicem articuli penultimi vix attingente, productus, armatus. Ramus exterior 5-ti paris apud feminam 3-articulatus, processu unguifoimi articuli secundi arcuato,. intus ad finem denticulato; articulus ultimus distinctus, aculeis 2 brevibus ornatus. Ramus interior l-articulatus, articulus 1-mus rami exterioris vix longitudine fere 'equante. Pedis dextri 5-ti paris apud marem ramus interior uni-articulatus apicem articuli 2-di rami exterioris attingens, apice acutus, pilis obsitus. Unguis terminalis. rami exterioris simpliciter arcuatus. Seta accessoria brevis. Pes sinister articnio 2-do- rami exterioris oblongovate, versus apicem intus subtilissime aculeato et duos acu- leos majores portante, ad basin in lamina ciliata extante. Ramus interior simplex, versus apicem ciliatus, vero longus et ultra medium articuli 2-di rami exterioris por- rectus. Animal pleurumque pellucidum, interdum czruleo vel rubro ornato. Long. feminze 1.1-1.2 mm. A small species of rather robust form found associated with D. albuquerquensis in the tank of the city water works of Albuquerque, New Mexico. The greatest width is somewhat in advance of the middle. The last cephalothoracic segment is ornamented with small Spines only. The first abdominal segment bears on either side a sharp. Spine. The second segment is quite short. Stylets of moderate length with short sete. Antenne reach the stylets. Antepenult segment with alamina along its distal aspect terminating in a slightly curved process shorter than the penultimate segment. The segment following the geniculation has a hyaline lamina. The fifth foot of the female has a single-jointed inner ramus of considerable length armed at the apex with two spines and small cilia. The claw of the outer ramus is moderately curved and armed near the tip with a series of teeth, the terminal joint is distinct and bears two small spines. The inner rami of the male feet of the fifth pair are simple and rather long. The terminal claw of the right leg is slightly curved and of moderate length, while the accessory spine is nearer the apex of its. ENTOMOSTRACA OF MINNESOTA. g' segment than the base and is weak and short. The outer ramus of the left foot has a cushion of small spines and two small teeth at the apex and a ciliate lamina along its inner aspect. The inner ramus of this leg is nearly as long as the outer. * Diaptomus sanguineus Forbes. PLATES V, Fias. 8, 9; XIII, Fie. 12. Forbes ’76; Herrick ’83 and ’84; De Guerne and Richard ’89; Marsh ’93. A compact species, usually brilliantly colored. Greatest width in front of but near the middle of the cephalothorax. Last segment of thorax laterally produced and armed with two strong spines and pro- duced or ‘‘humped” dorsally. First segment of abdomen long, armed with strong lateralspines. Second segment very short. Caudal stylets rather longer than broad, ciliated, setze short. The antenne reflexed nearly reach the stylets. The right male antenna is strongly genicu- late and its antepenultimate segment is armed with a hyaline lamella forming a short hook apically. The right foot of the male is remark- able for the thick segment bearing the two rami, the outer of which is rather long. The terminal claw is rather short and not strongly curved, and seems at times to be crenulately toothed near the apex. The accessory spine is a little beyond the middle of the second seg- ment of the outer ramus, of which the proximal segment is very small. The inner ramus is short and unarmed (it is incorrectly represented by Forbes as being on the outer aspect), and on the outer aspect is a long spine larger than the ramus, but not jointed, beneath which is an accessory spine or bristle. The left foot is very short and compact —‘‘fleshy’’ is a suggestive word. The inner ramus is short and un- armed, while a strong spine occupies the corresponding position ex- ternally. The apical segment bears a stout claw externally and a - smaller opposable spine internally. The species is quite variable. Individuals from very stagnant water may reach 2.0 mm, while others in clear pools do not exceed 1.7 mm. The mean may be taken as1.8mm. The curious fact that there is a succession in rain pools in spring beginning with D. stagnalis and passing through several varieties to D. sanguineus later in the season, has led the writer to suspect an actual transition. Of the heterogenetic character of these forms there is absolute proof as in Cyclops, but much farther study is necessary to clear up the most interesting biological laws involved in the distribution of these species. * Diaptomus minnetonka Herrick. PLATE XIII, Fies. 8-10. Herrick ’84; De Guerne and Richard ’89; Marsh ’92. We are inclined to agree with Marsh that this form is but one of the many variations of D. sanguineus. Besides being somewhat smaller than D. sanguineus the species differs from it in minor details of the 72 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. feet. Theinner ramus of the right fifth foot of the male is slender and longer than in sanguineus; this is also true of the inner ramus of the left foot. The terminal segment of the outer ramus is provided with the same armature as sanguineus and also bears a ciliated plate along its inner aspect. The terminal claw of the right leg is toothed. In the female the inner ramus is more or less distinetly two-jointed and the claw of the outer ramus is toothed. Length of male 1.4 mm. Color dark. In the long antenne the species differs from sanguineus, which it resembles in the armature of the last thoracic and first ab- dominal segment. * Diaptomus armatus Herrick. Herrick ’82 and 84; De Guerne and Richard ’89. The form, which was indicated by only a few points, in the hope that it might be subsequently rerecognized, has never again been seen. It appears to be allied to sanguineus. The antenn are said to be shorter than the body, the caudal stylets narrow, the right male an- tenna has a hook upon its antepenultimate joint and is strongly gen- iculate. But the one feature which may determine the species is the existence of a tooth or spur near the base of the claw of the right fifth foot of the male. * Diaptomus oregonensis Lilljeborg. PLATES IV, Fias. 7-12; 1X, Fia. 3. De Guerne and Richard ’89; Marsh ’93. This species has been found only in Lake Minnetonka within the limits of Minnesota, though Marsh speaks of it as occurring in Wis- consin very generally in the smaller lakes. It was first found near Portland, Oregon, by Trybom. The species is of medium size (1.5 mm. long) and rather graceful habit. The antennze extend beyond the caudal stylets and are strongly spined. The last two thoracic segments are confluent, and bear ove or two small spines laterally. The first segment of the ab- domen is as long as the remainder and mucronate. The caudal stylets are nearly twice as long as wide. The right male antenna is moder- ately modified, its antepenultimate segment being unarmed. The apical segment ofthe outer ramus of the fifth pair of feet in the female is obsolescent with two sharp spines. The claw of the penultimate segment is short and slightly curved; the inner rami are one-jointed and armed with two large spines and fine bristles apically. The fifth feet of the male are sub-equal, the terminal claw of the right foot being geniculately curved and rather long. The accessory spine is near the end of the preceding segment which also bears a small spine near the middle. The inner ramus of the right foot reaches to the spine just ENTOMOSTRACA OF MINNESOTA. 73 mentioned and bears two teeth. The terminal segment of the left foot is expanded and carries two movable spines and a spur; according to Richard’s drawing the spines are dentate and there are accessory ciliar pads along the inner aspect of the outer ramus. The inner ramus is longer than the basal segment of the outer ramus and is cili- ated apically. * Diaptomus pallidus He rick. PLATES IV, Fias. 1-6; V, Fie. 10; XIII, Fie. 17. Herrick ’83 and ’84; De Guerne and Richard ’89; Marsh ’93; Turner ’92. De Guerne and Richard in their monograph quite overlook the original figures and description, for the remarks in Microscopic Ento- mostraca cannot be regarded as a scientific description. It is not to be wondered at that it is considered insufficiently described. This was to be expected from these authors, but is more remarkable from Marsh, who had the paper of 1883 before him but fails to note the figures and description, which, though poor (being prepared on a rail- road journey), are diagnostic in respect to the armature of the fifth feet. The credit of completing the description belongs to Marsh. A slender species of medium size. Cephalothorax widest near the middle; head partially separated by a suture; last cephalothoracic seg- ment fused with its predecessor, armed with one or two minute spines on either side. First abdominal segment long as remainder; second segment shorter than the third. Stylets twice as long as wide. The antenne are longer than the sets or at least reach beyond the end of the stylets. Right male antenna without special armature. The ter- minal segment of the outer rami of the fifth foot of the female is obso- lescent and bears two unequal spines. The claw is short and moder- ately curved. The inner ramus is as long as the basal joint of the outer ramus and bears two long curved spines and a few cilia. The fifth feet of the male are nearly equal, neglecting the claw of the right which is of moderate length and geniculately curved. The accessory Spine is short and near the apex, while a smal! tooth is situated about at the proximal one third of the inner aspect. The inner ramus of the right foot reaches about to this tooth. The armature of the outer ramus of the left foot is peculiar and was not correctly figured by myself or Marsh. Fig. 2 of the plate is a camera drawing of the usual appearance. Fig. 6 is drawn so as to interpret the appearance. There is a movable claw, blunt at the tip and bearing a knob on the inner aspect which fits into the concavity of a basin-shaped projection whose outline is mistaken for a curved claw in most lights. Fig. 6 was taken from a specimen found in Lake Minnetonka. In general, the species prefers clear water. Fig. 1 represents a subimago form, with the first set of - as a aa ig 4: * e _ - 74 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. eggs, and is less slender than the adult. The fact that all these species are heterogenentic has been frequently reported by the writer. Length 1.2 to 1.3mm. Antennal.3 to 1.5 mm. Marsh found the Species but once, near Marquette. * Diaptomus piscine Forbes. PLATE V, Fia. 13. Forbes ’93. A species of medium size (1.75 mm. long), having the last thoracie segment not produced but armed with spines. The fifth feet of the female has the apical segment of the outer ramus obsolescent and the long one-jointed inner ramus provided with spines half as long as the ramus. The male feet are very like those of D. leptopus. The outer ramus of the left foot has a quadrate basal joint much wider than the second segment, which bears a smal] blunt spine and a long curved seta. The inner ramus is nearly as long as both the segments of the outer, and terminates in a broadly rounded, or subtruncate, thickly ciliate end. The terminal claw of the outer ramus of the right leg is short, ciliated; the accessory spine being near its base. The inner ramus is longer than the basal joint of the outer, terminating in a blunt ciliated end. Diaptomus laciniatus Lilljeborg. PLATES VIII, Fie. 15; X, Fie. 12. . De Guerne and Richard ’89. This alpine and northern form may be at once recognized among its congeners by the fact that the two last thoracic segments are pro- duced on either side into large projections, of which those of the last one are enormous and are armed with two minute spines. The first abdominal segment is as long as the rest of the abdomen. Caudal stylets short. The antenne extend beyond thestylets. Length with- out stylets 1.8 mm. to 1.2 mm. Diaptomus castor (Jurine.) PLATE IX, Fia. 5. Jurine ’20 (Monoculus castor); Koch ’35 (Glaucea rubens); Lilljeborg ’53; Lubbock °65; De Guerne and Richard ’89. The confusion of several species under this name and loose de- scriptions of European authors stood in the way of any differentiation of non-European species until very recently. In fact, antil the ap- pearance of De Guerne and Richard’s work no writer could feel safe in the attempt to distinguish species in this genus. All references to D. castor in America are erroneous. In our own case PD. leptopus has been most often so called. ENTOMOSTRACA OF MINNESOTA. (i A large robust species (2.5 to 3.0 mm. long), with the last abdomi- nal segment produced into two long acuminate and mucronate lobes. The first abdominal segment is also produced and spined. The an- tenn are short, barely reaching the second abdominal segment. The third joint of the outer ramus of the fifth foot is large and furnished with two unequal spines, one being very long. The claw is short and serrate. The inner ramus is two-jointed and armed with one very long and one short spine. The inner ramus of the right foot is two- jointed, and of the left, one-jointed in the male. Two varieties or subspecies are recognized as separate species, but seem to be due to difference of station simply. Diaptomus glacialis Lilljeborg. PrAri EX? GPIGas: De Guerne and Richard ’89. The last two thoracic lobes are confluent dorsally and are produced into even longer lateral processes than D. castor. Processes of the rostrum differ from those of D. castor in being elongate, sinuate, and obtuse. The fifth feet of the male differ chiefly in that the inner ra- mus of the right leg is very indistinctly two-jointed. There is oc- casionally a rudimentary appendage upon the antepenult segment of the male antenna. 3.0 mm. long. Glacial waters of Nova Zembla, ete. Diaptomus mirus Lilljeborg. PLATE VIII, Fie. 8. De Guerne and Richard ’89. A species or variety even larger than D. castor (3.6 mm. long) and differing very little from D. glacialis. The lateral projections from the last thoracic segment (which is distinct) are smaller, and the first abdominal segment is not produced into great lateral processes. The fifth feet are almost identical in the two species. The fifth feet of the males differ only in the proportional development of the parts. The form was found in Siberia by the Nordenskiold expedition. Diaptomus sancti-patricii Brady. PLATE XXXIII, Fies. 9-11. Brady 791. Posterior angles of the last thoracic segment very much produced so as to form attenuated spines. Anterior antenne reaching about as far as apex of furca; penultimate joint of the anterior antenna of the male entirely destitute of marginal process. Inner branch of the fifth pair of feet in the female indistinctly biarticulate, nearly as long as * 76 GEOL. AND NAT, HIST. SURVEY OF MINNESOTA. the first joint of the outer branch, and bearing three minute apical] sete. Last joint of the outer branch smail, the larger apical seta not reaching as far as the extremity of the claw of the penultimate joint. Inner branch of the right foot in the male simple, mucronate at the apex, and reaching beyond the middle of the last joint of the outer branch; terminal claw of the outer branch strongly faleate, and delicately ciliated on the inner edge; lateral spine attached near the middle of the last joint, long, slender, and finely ciliated. Fifth foot of the left side (male) terminating in a suberescenti form hyaline lamina, the inner edge of which is delicately crenulated. Length of male and female about 1.55 mm. Diaptomus lilljeborgi De Guerne and Richard. PLATE IX, Fia. 6. De Guerne and Richard ’88! and ’89. This rather large species (2.0 mm. long) is sufficiently identified by the greatly expanded inner ramus of the right foot.. The last thoracic segment is alate and mucronate; the first abdominal being also spined. The antenne are scarcely longer than the thorax, and that of the male as in D. castor. Algiers. Diaptomus roubaui Richard. PLATES VIII, Fia. 2; IX, Fia. 11. Richard ’88; De Guerne and Richard ’89. This, which is perhaps the largest species of the genus (5.0 to 6.0 mm.) is recognized by the expansion of the right side of the first ab- dominal segment to form a rounded spinous protuberance while the third and fourth segments of the male are produced and opposable. The antenne scarcely exceed the thorax. The female fifth feet are like those of D. castor. The inner rami of the male feet are one- jointed; that of the right foot being curved and thickened at the apex, that of the left foot indistinctly two-jointed and as long as the basal segment of the outer ramus, which is narrow and armed with spines internally. The terminal joint of the outer ramus is swollen and pilose and armed with two thick spines. * Diaptomus tyrrelli Poppe. PLATE X, Fi@. 9. Poppe ’88. A species from Summit lake (altitude 5,300 feet, in the Rocky mountains) and Centreville, Cal., of moderate size (1.9 mm.) and greatly expanded and spined thoracie angles. The first abdominal segment is as long as the remainder and expanded and spined ante- ENTOMOSTRACA OF MINNESOTA. A 7 riorly. The second segment is transversely wrinkled. Antennie ex- tend to the stylets. Right male antenna with an unarmed antepenult joint. Third joint of outer ramus of fifth feet obsolescent, inner ramus slender and as long as the basal joint of the outer ramus. The outer ramus of the right male foot with a small hyaline process; accessory Spine near the middle of the second joint smal]. The inner ramus is short and acuminate. Inner ramus of left foot long, two-jointed, hir- sute apically. Outer ramus short. Diaptomus theeli Lilljeborg. PLATE VIII, Fic. 11. De Guerne and Richard ’89. A species very much like D. laciniatus, except that the last two thoracic segments are not both produced into long projections, as in that species, the last being’ moderately produced and mucronate. The first abdominal segment is very long (as in the last), and some- what expanded anteriorly. The fifth feet of the female have the ter- minal segment of the outer ramus distinct and the inner ramus gen- erally (in old forms) two-jointed. There is a small hyaline lobe from the inner aspect of the peduncle of the right leg in the male. The inner ramus of this leg is curved and acuminate. The inner ramus of the left leg is shorter than the basal joint of the outer ramus and acute, with a small spine near the apex. 2.0 mm. long. Collected by the Nordenskiold expedition in Sibera. Diaptomus lobatus Lilljeborg. Pra) Vib Rraae De Guerne and Richard ’89. A species occurring with the last, from which we are unable to find any sufficient reason for separating it. The last two thoracic seg- ments are partly fused, and the last segment projects somewhat more than in D. theeli, and there are minor differences in the feet but of very doubtful value. Size the same. Such differences as exist may be gathered from the figures. Diaptomus affinis U)janin. PLATE X, Fia. 10. Uljanin ’75; De Guerne and Richard ’&9. A small form from Turkestan approaching D. denticornis, but lack- ing the armature of the male antenna. The first abdominal segment is unarmed, while the last thoracic has merely two small spines. Antenne reach the end of the last abdominal segment. The Jast joint of the males : i. hee 3 * “- + 4 78 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. outer ramus of the fifth feet of the female obsolescent, inner ramus one-jointed, longer than the basai joint of the outer ramus. The fig- ures of the male feet are imperfect, but indicate small one-jointed in- ternal rami on both sides. 1.6 to 1.4 mm. long. Diaptomus amblyodon Marenzeller. PLATE IX, Fie. 2. Marenzeller 73; Kortchaguine ’73 and ’87 (D. bogdanowi); De Guerne and Richard ’89. A large species very nearly allied to D. gracilis (4.0 to 4.5 mm. long). Last segment of the thorax ornamented with two spines. First abdominal segment with a conical process on either side armed with a long spine. Antenne extending to the end of the thorax. Last segment of the outer ramus of the fifth foot of the female well de- veloped, inner ramus one jointed, equaling the basal joint of the outer ramus and bearing three set; the clawstrongly toothed. Inner rami of the male fifth foot one-jointed, short, unarmed. The basal joint of the outer ramus of the right leg with a small lobe. Apical segment ofthe left leg densely spiny, with two larger spines. We receive too late to enter the above list in the appropriate places descriptions of two species of Diaptomus by Professor Marsh (94). The descriptions are given verbatim with a reduced repro- duction of the figures. * Diaptomus mississippiensis Marsb. PLATE XLVII, Fies. 1-3. ‘‘OF moderate size. The first two segments of the cephalothorax are nearly equal in length, and together form somewhat less than half the cephalothorax. The last segment of the cephalothorax is armed behind with two minute spines. ‘*The first segment of the abdomen of the female is as long as the remainder of the abdomen and the furca; it is dilated laterally and in front, and bears two prominent lateral spines, the right spine being con- siderably larger than the left. The second segment is somewhat shorter than the third, and the third and the furca are of about equal length. ‘*The antenne reach beyond the furca. The right antenna of the male is swollen anterior to the geniculating joint, and the antepenul- timate joint is without armature. ‘‘The outer ramus of the fifth foot of the female is two-jointed, the third joint being represented by two spines. The inner ramus is one- jointed, a little longer than the first joint of the outer ramus, and armed at the tip with minute sete and two rather long spines. ‘*In the right fifth foot of the male the basal joint is. dilated on the inner margin. ‘The first joint of the outer ramus is slightly broader than long. The second joint is elongated, quadrangular, with the ENTOMOSTRACA OF MINNESOTA. 79 lateral spine situated at the distal end. The terminal hook has the symmetry of the curve broken by two rather abrupt angles, and its inner margin is armed with fine serrulations. The inner ramus is one-jointed, and reaches about half the length of the second joint of the outer ramus. “The left fifth foot of the male reaches to about the middle of the second joint of the outer ramus of the right. The first joint of the outer ramus is as broad as long. The second joint is armed at tip with two finger-like processes, and both joints are armed within with minute hairs. The inner ramus is one-jointed, and nearly equal in length to the outer ramus. Length of female, 1.2 mm.; male, 1.1 mm. ‘**This species was found in some material kindly furnished to me by Professor E. A. Birge. The collections were made in January and February, 1893, in small lakes and ponds in Mississippi. It was the only Diaptomus in the collections, and was found in nearly all of them. It will be noticed that it bears a somewhat close resemblance to D. graciloides Sars.”’ . * Diaptomus birgei Marsh. PLATE XLVII, Fias. 4-6. *“Of moderate size. The first segment of the cephalothorax is nearly equal in length to the three following. ‘“*The first segment of the abdomen of the female is as long as the remainder of the abdomen and the furea. It is much dilated in front. The second segment is nearly twice as long as the third, and about equal in length to the furca. The second and third joints are very closely united. “The antennz extend to the end of the furca. The right antenna of the male is much swollen anterior to the geniculating joint; the an- tepenultimate joint is produced on its distal end into a short, blunt process, which makes very nearly a right angle with the longitudinal axis of the joint. ‘*The outer ramus of the fifth foot of the female is two-jointed, the third joint being represented by twospines. The inner ramus is one- jointed, hardly as long as the first joint of the outer ramus, and armed at the tip with minute set and two rather long spines. **The basal joint of the right fifth foot of the male is elongated, tra- pezoidal in form, it greatest breadth being at its distal extremity. The first joint of the outer ramus is broader than long, armed on its inner margin with a broad, thin expansion of the integument. The second joint is elongate, broader at base; the lateral spine is situated at about the middle of its length, is long and stout, and armed on its inner margin with fine serrulations, The terminal hook is slightly 80 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. angular and armed with fine serrulations on its inner margin. The inner ramus is one-jointed, equaling in length the first joint of the outer ramus. ‘*The left fifth foot of the male reaches slightly beyond the first joint of the outer ramus of the right. The basal joint is quadrangular, con- siderably shorter than the right basal joint. The first joint of the outer ramus is about twice as long as broad. The second joint is slightly longer than the first joint; it is expanded at base, where it is armed with fine hairs, and terminates in a finger-like process bearing a falciform spine. The inner ramus extends to about one-half the length of the second joint. Length of female, 1.5 mm.; male, 1.3 mm. ‘‘The material in which this species was found was collected by Professor E. A. Birge at New Lisbon, Wisconsin, and only a few indi- viduals were found. I have expected to find it in the collections from other Wisconsin localities; but so far my search has been without suc- cess. It isa clearly marked species resembling the European D. gracilis Sars more closely than does any other described American species. The characters of the fifth feet, however, separate it from the European form. ‘*T have taken the liberty of naming this species in honor of Profes- sor Birge, to whose kind assistance and encouragement I have been greatly indebted.” GENUS BROTEAS Loven. 1845. Thorax five-jointed. First antenne multiarticulate; second pair bi-ramose. Swimming feet four pairs, bi-ramose, outer ramus three- jointed, inner two jointed; fifth feet dissimilar in thesexes. The third pair of maxillipeds falciform. Abdomen of the male six-jointed, in the female two-jointed. The single known species, B. falcifer Loven (Plate X, Fig. 16), a large slender form (4.0 mm. long), occurs in salt pans near Port Natal. GENUS HETEROCOPE Sars. 1863. Cephalothorax six-jointed; last thoracic segment more or less divari- cate alike in the two sexes. Abdomen of female three-jointed, of the male five-jointed. Caudal stylets; larger sete three. Antennz 25- jointed; in the male right antenna a geniculating joint between seg- ments 18 and 19, the six preceding somewhat tumid. Swimming feet four pairs, of which the outer rami three-jointed, the inner one- jointed. Fifth feet of female simple, three-jointed, those of the male dissimilar; the left cheliform. Abdomen of the male symmetrical. Heterocope is obviously the eastern homologue of Epischura. The three species of this genus may be tabulated thus, following De Guerne and Richard: a - . ‘ ENTOMOSTRACA OF MINNESOTA. 81 I. Antennz shorter than the body. Stylets armed at the angle with a short non-ciliated seta. The female has no appendages at the genital orifice. The last segment of fifth foot on the right side MEME BOE rw. . ee tee ce --e «6~. SAliens.and borealis II. Antennz longer than the body. Stylets without the setz at the angle. Female with eight appendages at the genital orifice. Last joint of the male right fifth foot long and straight. . . appendiculata Heterocope saliens Lilljeborg. 1862. PLATE X, Fia. 14. Last segment of the fifth feet of the female short and broad, teeth of its internal aspect distinctly bifid. The prolongation of the inner aspect of the antepenult joint of the left fifth foot of the male incurved, not reflexed at its end. Heterocope borealis Fischer. 1851 PLATE X, Fie. 15. Last segment of the fifth foot of female long and straight, teeth less distinctly bifid or trifid. Prolongation of male left foot much curved and reflexed at the end. Heterocope appendiculata Sars. 1863. PLATE XI, Fia. 3. Two other species, H. alpina and H. romana, have been described by Imhof (’88). These forms remain imperfectly known and may be simply young of other species. GENUS EPISCHURA Forbes. 1882. Related with Heterocope Sars. The thorax is six-jointed, the last two segments partly united. The abdomen is five-jointed in the male and four-jointed in the female. Antenne 25-jointed, the right male being geniculate. Abdomen of male with prehensile appendages, often moreor less distorted. Inner rami of swimming feet one-jointed. Fifth feet one- branched, in the male modified for prehension. Caudal stylets with three long sete. The first mention of an animal of this genus seems to be Pickering’s description of Scopiphora vagans from deep water in Lake Ontario. It seems almost certain that the species so imperfectly described in Dekay’s Crustacea of New York, is none other than a species of Mpischura, but I hesitate to substitute for a name accompanied by good descriptions and figures, and one which has already been incorporated to some extent into our literature, one which is founded on a description so imperfect and general that one incidental character alone enables one to guess its application. The following is Pickering’s description: 82 GEOL. AND NAT, HIST. SURVEY OF MINNESOTA. ‘‘Body small, eye single, near the anterior margin of the shield. Antenne large, and as long as in the preceding genus (Cyclops), and has the same motions in the water. Abdomen terminating in two styles, each with three sete; last or three last joints. Ovaries none; legs spiny.”’ What is meant by the ‘‘brush’’ fails to appear, unless the speci- mens were ornamented with some parasitic plants or animals. The three setze of the caudal stylets and long antennz will place this form in no American genus save Epischura. But even this statement of Pickering may be held doubtful. * Epischura lacustris Forbes. PLATE XIII, Fig. 15. Forbes ’82; Herrick ’84 and ’87; De Guerne and Richard ’89. ‘‘The second segment of the abdomen of the male is twice as long as the first, and produced to the right as a large, elongate, triangular process, somewhat hooked backwards at the tip. The third segment is similarly produced, but rounded and expanded at the tip, which is roughened before and behind. ‘‘From the right side of the fourth segment arises a stout process bearing at its apex a hatchet-shaped plate with seven broad obtuse serratures on its anterior margin. This process is roughened behind, where it is opposed to the concave side of the left ramus of the furea. From the same side of the fifth segment, a short flattened plate, ofa spatulate or paddle-like form, extends forward above or beyond the toothed process just mentioned. ‘‘The antenne are 25-jointed, and reach to the second segment of the abdomen. There are especially prominent sensory hairs on the first and third joints, borne at the tips of long spines. The antennules are short, the ramus apparently but three-jointed, the short, median joints common in this appendage being only obscurely indicated. The mandible has but seven teeth, the first simple and acute, separated from the second by an interval about equal to the second and third, the second to the sixth bifid, the seventh entire and acute. The usual plumose bristle is replaced by a sharp, simple spine. ‘‘The outer ramus of the fourth pair of legs has two teeth at the outer tip of each of the two basal joints. The terminal joint of this ramus is armed as follows: a short simple spine at middle of outer margin and another at the distal outer angle; a single and long terminal seta, strongly and sharply toothed externally and plumose within, and four long plumose set attached to the inner margin. ‘The left leg of the fifth pair in the male, viewed from behind, has the basal joint very large, broader than long, with the inner inferior angle produced downwards as a long, stout, curved process or arm as ENTOMOSTRACA OF MINNESOTA. 83 long as the two remaining joints. The second joint is trapezoidal, shortest within. The third joint is about half as wide at base as the first, is straight without, with a sharp, small tooth at its distal third, and bifid at tip. On the inner margin this joint is at first dilated a little, and then deeply excavated to the narrow tip, to receive the lower end of the left leg, the lower two-thirds of this margin forming the segment of a circle. ‘The right leg is two-jointed, the first joint twice as broad, enlarged at the lower end, forming an auriculate expansion at its inner inferior angle. The second joint is conicai in outline and about two-thirds as long as the first. | ‘The terminal bristles of the rami are very broad and strong in the female, the outer one especially having an extraordinary size and thickness. There is also at the outer angle of each ramus a short, stout spine, that on the left ramus being inflated like the outer bristle. Length .065 in. ““The legs of the fifth pair in the female are three-jointed and simi- lar, the basal joint short and broad, the second two and one-half times as long as wide. The leg terminates by four diverging teeth, preceded by two others, one on each side. ‘‘Taken in the towing net abundantly in October, 1881, at Grand Traverse bay; also obtained rarely by Mr. B. W. Thomas, from the city water of Chicago.”’ Occurring in Minnesota, probably in Lake Superior. * Epischura fluviatilis Herrick. PLATE XIII, Fies. 14, 16. Herrick ’83, ’84 and 787; De Guerne and Richard ’89. “Similar to the above but smaller (0.04 in.). The females are very similar, though the fifth feet are more elongate and differently spined. The abdomen is perfectly straight and the three caudal setz are of nearly equal size. The claw is armed with eight teeth, all but the first of which are emarginate. The abdomen of the male is straight, but has a strong process on the left side which bears a movable claw laterally and a small second segment which terminates in two small spines. The fifth foot of the male is peciliar; the inner ramus (or the left foot) lamelliform, one-jointed, with two opposable claws; the right branch is simple and three-jointed, in form like that of the female. Here we have the most marked difference between the two species. Found in Mulberry creek, Cullman county, Ala. Although a consid- erable number were examined no oviferous females were found, while the males contained the spermatophores and can hardly be thought immature, and, as it is inthe male that the most marked differences appear, the two species seem certainly distinct.’’ od, Pe AON 4 ni ‘- * 84 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. It is to be regretted that no opportunity has occurred to observe this species since the above was written. It is very probable that mature examples would inodify as well as extend the above. It is a bit amusing to find De Guerne concerned over the discrepancy of our locating ‘‘baie de Mulberry’’ in a mountain region—a difficulty which would disappear should he grasp the English usage of ‘‘ereek’’? which he has translated ‘‘ baie.’’ * Epischura nevadensis Lilljeborg. PLATE XI, Fias. 1, 6, 8. De Guerne and Richard ’89. Of moderate size. Cephalothorax five-jointed; last two confluent; last segment not devaricate, rounded. Abdomen three jointed in the female. Caudal stylets shorter than the preceding segment; slightly ciliated internally; caudal seta equal and similar; externally a short spine. Abdomen of male five-jointed, curved to the right, similar to that of FE. lacustris, second and third segments nearly equal in length, the first shorter; the second segment produced on the right side into a very large wing-like process, denticulate along its hinder border and emarginate at the tip; third segment with a shorter, smooth and broadly rounded process. The fifth segment with a process on both sides. Antenne not reaching the base of the stylets. Antepenult joint of male right antenna not appendaged. Fifth feet of female uni- ramose, three-jointed, more robust than usual. Apical joint with six teeth, of which four are longer. Fifth feet of male uni-ramose, dissim- ilar. Right foot apparently two-jointed, the basal joint thick with a lamellate and denticulate process at the end, second joint a thick claw. First joint of the left foot a very large hook; third joint incised inter- nally, the shallow excavation ciliated, and armed apically with two spines. Length of female 2.0 mm. Found by A. G. Eisen in the Sierra Nevada region, Lake Tahoe and Echo lake. * Epischura nevadensis Lilljeborg. Var. Columbize Forbes. PLATE XI, Fias. 4, 10. Forbes ’93. This alpine form is not only a little larger but the thorax is more distinctly jointed. The antennz of the female reach to the posterior end of the penultimate segment of the abdomen, The first segment of the abdomen is as long as the two following together, and the stylets are as long as the preceding segment. The abdomen is not curved as in EF. lacustris. The three caudal sete are all similar and of equal width. There is a stout conical spine at the outer distal angle and a soft seta at the inner angle of each stylet. , ENTOMOSTRACA OF MINNESOTA. 85 ' The fifth legs of the female are broader proportionally than those of /acustris but more slender than those of EL. nevadensis. The last seg- ment is four times as long as broad and bears six (7) teeth, of which four are terminal. The second, third and fifth segments of the male abdomen bear lateral processes extending toward the right. The first three segments are subequal. The lateral process of the second has the form of a stout but thin lamina projecting to a distance equal to the width of the segment; it is acute at the apex, with the pointa little recurved, convex and smooth in front, and nearly straight be- hind, except that this edge is irregularly serrate throughout and deeply emarginate where it joins the segment. This blade is strongly curved ventrad like the following. The third segment bears a broad thin lamina which projects outward, as wide as long, broadly rounded at the end, simple but strengthened beneath by a ridge of chitin. From the fourth segment spring two processes, the ventral being nearly similar to that of nevadensis. The dorsal process is a small irregular plate curving forward, inward and downward. Length of female 2.12 to 2.4 mm. * Epischura nordenskiceldi Lilljeborg. PLATE XI, Fics. 2, 5, 9. De Guerne and Richard ’89. This species, from St. Johns, Newfoundland, is the largest of the genus (2.9 mm.) and is remarkable for the slender, slightly armed ab- domen. Cephalothorax robust, abdomen exceedingly slender, four- jointed in the female, anterior two somewhat fused, third segment longer than the fourth. Caudal stylets twice as long as wide, ciliated internally; caudal set similar and equal. Male abdomen five-jointed and slightly flexed toward the right, second and third joints equal and half as long again as the first. The second joint is armed with a rather small, slightly curved, and notched at the tip. The process of the third joint is very small and acute; that from the last is directed cephalad and is blunt. Antenne reaching to base of stylets, 25-jointed. Geniculate antenna with the penultimate joint unarmed. Feet of fifth pair in the female uni ramose, three-jointed, nearly as slender as in £. lacustris though less so than F. fluviatilis, the joints nearly of equal length. The left fifth foot of the male closely resembles that of LE. columbie; the right differing from the other forms in having an acces- sory spine near the base of the inner aspect. GENUS OSPHRANTICUM Forbes. 1882. (—Potamoichetor, Herrick.) First reported as Potamoichetor before the Minnesota Academy of Sciences in 1879, but owing to a disastrous fire, publication was pre- vented, Priority probably belongs to Forbes’ name, since, although > Sees», o> 86 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. first printed in the tenth annual of this survey, the edition was not distributed till after the August issue of the American Naturalist of 1882, containing the description above alluded to. Forbes says this genus has antenn 23-jointed; all the specimens we have gathered from Minnesota to Alabama had 24-jointed antenne. The original description of ‘‘Potamoichetor’’ is appended. ‘*Cephalothorax six-jointed, distal segments evident; abdomen, in the male, five-jointed, in the female four-jointed; antennz 24-jointed, the right geniculated as in Centropages (=Ichthyophorbia); first pair of feet with the rami both three-jointed, like the following; feet of the fifth pair, in the female, like the preceding, but with a spine of the joint preceding the terminal one enlarged and divaricated somewhat as in Centropages; in the male, the right with a two-jointed outer ramus, the terminal joint of which is spined and bears near its base a blunt expansion of its inner margin; outer ramus of left foot _ three-jointed, armed with unequal spines; inner branches smaller, similar, three-jointed; the terminal joint bearing curved spines; ovary and testes as in Diaptomus, with which the mouth parts agree in the main; eyes median, confluent.’’ Ovisac very large, elongate. Our own experience is that the single species of this genus prefers estuaries of running water. Forbes, however, has taken it from swamps and wayside pools. *Osphranticum labronectum Forbes. PLATES XII, Fies. 1-8, 13, 14; LIX, Fies. 7, 8. Forbes ’82; Herrick ’82 (Potamoichetor fucosus), ’84 and ’87; De Guerne and Richard ’89. ‘‘Rather slender, and in size, as well as general appearance, resem- bling the smaller forms of Diaptomus; antenne rather stout, reaching but little beyond the feet, appendaged as in Diaptomus, in the male strongly geniculated, but somewhat variously so; the six joints pre- ceding the terminal four are thickened; those preceding the joint or hinge are arcuate on the distal margins; the secondary antenne are about asin Diaptomus; mandibular palp two-branched, the outer three- jointed, the inner two-jointed; the terminal joint of the shorter branch bearing seven sete, of the other four, the proximal joint of the former with three stout spines; the maxille nearly like Diaptomus; the pro- cesses have respectively the following numbers of set: the basal plate eight, the small processes at base of posterior branchial append- age one, the appendage itself twelve, terminal portion three groups, first containing nine, the second three, and the third four or five, the upper of the anterior processes two, and the lower three; fifth feet nearly like the others in size; the right in the male having the outer ENTOMOSTRACA OF MINNESOTA. 87 branch but two-jointed by the coalescence of the two outer to form an arcuate and deformed appendage, armed at the end with three stout equal spines; corresponding branch of left foot three-jointed; the ter- minal joint bearing three unequal spines, each of the preceding joints only one; inner branches similar, three jointed; terminal joint being short and armed with three short lanceolate sete and three longer ones, two of which are curved so as to be slightly prehensile; fifth foot of female with both rami three jointed; inner ramus much smaller; antepenult segment of the outer ramus extending into a large lanceo- late process; ovisac long-ellipsoidal or spherical, reaching nearly to the end of the caudal setie.”’ Professor Lilljeborg finds this species in Oregon, and as we have collected it in Alabama it may be regarded as ubiquitous in North America in suitable stations. FAMILY CYCLOPIDE. The family contains five genera, viz.: Thorellia, Cyclops, Oithona, Lophophorus and Cyclopina; passing, by the genera Misophria and Pseu- do-cyclops, into the Calanide or marine Copepoda. The affinities of these little known genera need further study, as they are very inter. esting, the question being still open in how far the cyclopoid forms are altered by adaptation to saline habitat, if such an adaptation takes place at all. Cephalothorax ovate and usually much more robust than the abdo- men; anterior antenne seldom longer than the cephalothorax, those of male alike on both sides and modified for the purpose of clasping; posterior antennz unbranched (i. e., palpus wanting); palps of mandi- bles and maxille usually well developed; foot-jaws mostly less devel- oped than in Calanide; first four pairs of feet as in Calanide, fifth pair rudimentary, alike in both sexes, and usually one- or two-jointed; ovisacs two. The circulatory system of this family is partly lacunal and has been thought to be entirely so in the genus Cyclops. Closer observa- tion, however, shows that there is something like an imperfect central organ at the point occupied by the heart of higher Copepoda. This was figured in my previous report, Plate V, Fig. 1, but no mention was made of the discovery. It has since been verified. The appa- ratus referred to is a modification of that described under Canthocamp- tus. In the second thoracic segment there is a set of swaying mem- branes which constitute a valvular apparatus, chiefly moved by the action of the stomach. The following analytical key from Brady will serve to differentiate the genera. 88 ‘GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. KEY TO THE FAMILY CYCLOPIDE. I. MANDIBLAR PALP OBSOLESCENT, a mere tubercle bearing two filaments. a. Second maxillepeds prehensile. ....... . . +. Thoreliia. b. Second maxillepeds not prehensile. . . ..... =... Cyclops. II. MANDIBLAR PALP TWO-BRANCHED. a. Secondary branch of palp many-jointed. . . ... ... . Oithona. b. Secondary branch one-jointed. * Fifth pair of feet foliaceous. . . . . . . Lophophorus. ** Fifth pair of feet cylindrical, two- or ehreeduuited: . . . Cyclopina. All these genera except Cyclops are marine. GENUS CYCLOPS. The sole representative of the genera of the Cyclopide here treated is the best known of the Copepoda. Every one is familiar with the “common Cyclops,’’ but few realize how many are the species included under this name. An attempt is here made to enable the student to recognize the more obvious distinctions upon which the genus is sub- divided and to identify such of the species as seem valid and at the same time recognizable without recondite study of development. Without attempting a complete elucidation of the synonymy, which is practically an impossibility, a proximate classification of all the species known to me is attempted. DIAGNOSIS: Cephalothorax robust, oval, broadest in front, com- posed, in the female, of nine segments. Antenne short, of less than twenty segments, in the male geniculate on both sides. Antennules one-branched, four-jointed. Mandiblar palp a small two-setose tu- bercle. First four pairs of feet two-branched, all the branches three- jointed. Fifth feet small, one- to three-jointed. In the male a still more rudimentary sixth pair. Eye single but composed of two facets. Ovisac double. As stated by Brady, the genus Cyclops is, as regards discrimination of species, one of the most difficult and puzzling of all the Copepoda. Chief among the causes of this difficulty is the- polymorphism and het- erogenesis which prevail, as well as the great susceptibility to the effects of the environment. Living as they do, in pools and streams, undergoing great seasonal and other variation, these forms offer ex- ceptional opportunities for the study of the plasticity of species. KEY TO THE GENUS CYCLOPS. I. Antenne 18-jointed. Il. Antenne 17-jointed. a. Fifth foot one-jointed.. 2. Sa a ee b. Fifth foot two-jointed. a os ~ ENTOMOSTRACA OF MINNESOTA. 89 * First joint of the fifth foot broad. . . viridis, 90; americanus, 91; ingens, 92; vernalis, 92; robustus, 93; parcus, 93; brevispinosus, 5; uniangulatus, ¢£6; leuckarti, 96; scourfieldi, 98; oithonoides, 98; dybowskii, 99; bisetosus, 99. ** First joint of the fifth foot longer than wide. 7 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, puichellus, 101; minnilus, 103; forbesi, 104. Tit Terminal segment of the fifth foot with threesete. . Signatus 105; var. coronatus, 106; var. tenuicornis, 106. Ill. Antennz 16-jointed, languidus, 107; modestus, 108; capilliferus, 109; een jointed. . . . .. »- «ff « ..« «+s « . insignis, 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. . . . capillatus, 115; crassicaudis, 115; varicans, 116. VI. Antenne Il-jointed. . . gracilis, 117; diaphanus, 117; affinis, 117; bicolor, 118. Mibeeaniennz 10-jointed, . . « . . . » «+. ~~. Dphaleratus, 120: Will Antenne eight-jointed. ..........s. . fimbriatus, 121. IX. Antenne six-jointed. .... . : | = ). 2equoreus, 122: The forms which have been fonorted with 18. -jointed antennz 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 antenne 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 ore long and one short seta. The stylets are longer than the two last abdominal segments, with relatively short sets, whose rel- ative size is nearly like those of ©. cuspidatus.”’ This species is reported by Cragin from near Cambridge, but has been seer by no other observer except the describer. *Cyclops ater Herrick. PLATES VI, Fias. 11, 12; XII, Fies. 9-12; XXI, Fies. 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.), 90 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. slender, tapering toward the end; formula* —=-~——-~—_~ _~ age ———; last three segments not elongate, the last being furnished with an unserrated, hyaline knife-like ridge as in ©. tenuicornis. Anten- nules much as in ©. 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 sete. 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. PLATE XIV. 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’72' (C. brevicornis); Uljanin ’75; Hoek ’76 (C. brevicornis); Rehberg ’801; 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 ’72! (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. tex. exterior; ap.—apical; in.—interior aspect. r ENTOMOSTRACA OF MINNESOTA. 91 tion than once supposed, C. ingens was united with C. gigas as an un- named variety of ©. 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 ©. 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 antenne 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. PLATE XIV. Subspecies Americanus Marsh. We quote Marsh’s description entire: **Cephalothorax oval, the first segment. being about half its total length. Antennz 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. Jurca about three times as long as its average breadth, the lateral spine sit- uated well towards the end. The first and fourth terminal set are short, slender and plumose, nearly equal in length. Of the internal set, 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: Frrst Foor. ex. 3 spines. (ex. 1 seta. Outer ramus jap. 2 sete. Inner ramus jap. 1 spine, 1 seta. in. 2 sete. in. 3 setz. SECOND AND THIRD FEET. ex. 3 spines. ex. 1 seta. Outer ramus {sp 1 spine, 1 seta. Inner ramus +; ap. 1 spine, 1 seta. in. 3 sete. in. 3 sete. FouRTH Foor. ex. 3 spines. ex. 1 seta. Outer ramus | ap. 1 spine, 1 seta. Inner ramus |S 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.”’ 92 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. The points of difference consist in the fact that the antenne# 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. Var. b. *Cyclops ingens Herrick. PLATE XXYV, Fias. 1-8. This is the largest form yet encountered in America and is rarely seen. It is a simple exaggeration of the last, there being no obvious distinctions except the size. It is occasionally over 4.0 mm. long in- cluding the set 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 Slaus is but a ‘‘post-imago”’ of C. lucidulus Sars. Still it is not to be forgotten that other species may sporadically develop 18 jointed an- tenn and then might lay claim to be considered (C. elongatus. 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 sets 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 zequante versus medium sparsim dein dense ciliata, ceteris duabus brevissimis et fere ejusdem longi- tudinis. Antenne 1 mi paris 17 articulate, breves et crassz 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, Frias. 12-15; X XI, Fia. 22; XXIII, Fic. 8; XXXIV, Fias. 1-8. Herrick ’&2 and ’84; Marsh ’93. This species, which is very near to ©. vernalis and C. 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 dacty], 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: wate Mec » 94 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. FIRST FEET. ex. 2 spines. ex. 1 seta. Outer ramus 4; ap. 2 set. Inner ramus 4; ap. 1 spine, 1 seta. in. 2 sete. in. 3 sete. SECOND FEET. ex. 2 spines. ex. 1 seta. Outer ramus jap. 1 spine, 1 seta. Inner ramus + ap. 1 spine, 1 seta. in. 3 sete. in. 3 sete. FouRTH FEET. ex. 2 spines. ex. 1 seta. Outer ramus ; ap. 1 spine, 1 seta. Inner ramus { ap. 2 equal spines. Gat 3 setz. \f 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 C. 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 antennze 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. Length 1.4to1.5 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 OC. brevispinosus Herrick, and it is not certain that this has not already happened to some extent. j ely Geen oo = x. y) 1 7 4 ENTOMOSTRACA OF MINNESOTA. 95 - 1884. PLATES XXIII, Fias. 1-4; XXIV, Fias. 7-12. *Cyclops brevispinosus Herrick. 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 (. 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 antenne 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. Onter ramus < ap. in. ex. Outer ramus + ap. in. ex. Outer ramus + ap. in. ex. Outer ramus { ap. in. 3 spines. 2 sete. 2 sete. Inner ramus SECOND Foot. 1 spine, 1 seta. Inner ramus 3 sete. THIRD Foot. 3 spines. 1 spine, 1 seta. 3 sete. Inner ramus FouRTH Foot. 3 spines. ex. 1 spine, 1 seta. Inner ramus + ap. 3 sete. in. | 3 spines. | i ( 1 seta. 1 spine, 1 seta. 3 sete. 1 seia. 1 spine, 1 seta. 3 sete. 1 spine. 2 spines. 3 sete. 1 spine. 2 spines. 2 setze. 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 mecctalepine. Hormula for antenne, —-=_~ ~~ $$ LLL. Antennules rather short. Length1.0 mm. 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 unianguiatus 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 ( 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. PLaTes XVI; XVIII, Fias. 1, A-3; 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 set. 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 mm., dorsal 0.06 mm.; the lateral seta is 0.036 mm. from the end. The antenne reach nearly to the base of the thorax when reflexed, and are quite strong. They resemble those of C. tenuicornis 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, 85, 95, 195, 117, 127, 155s 146, 1510, 1615, ,714. 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. tenuicornis. 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 antennz (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: ENTOMOSTRACA OF MINNESOTA. 97 First Foot. ex. 2 spines. ex. 1 seta. Outer ramus {8 2 setze. Inner ramus {iP 1 spine, 1 seta. in. 2 sete. in. 3 sete. SECOND AND THIRD 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 Foor. ex. 2 spines. ex. 1 seta. Outer ramus | 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 and another as long upon the middle of its inner side. The cement gland is of peculiar shape, resembling that of C. parcus exactly. The lastsegment 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’ ©. 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 as a basis upon which to distinguish other allied species. The form from the Southern States originally called C. tenuissimus 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 antenne 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 ©. 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- 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 Padueah, Ky., under the name ©. 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. tenuwissimus, nearly equalling the thorax. The last joint of the antennze 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’ C. leuckarti. Schmeil has decided, after examination of Sars’ specimens, that they belong to OC. 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 OC. 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 OC. 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 ©. 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 sete; the lateral seta near the PE ee lead me : i a ot 2 ENTOMOSTRACA OF MINNESOTA. 99 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 itsset greatly elongate, formula,_ = _-_=-_L-_~ SRC AA Oe the last two segments have a narrow hyaline membrane which is entire. Armature of fourth feet as follows: ex. 2 spines. ex. l1seta. Outer ramus |i 1 spine, 1 seta. Inner rans 8p 2 spines. in. 3 sete. in. 2setz. 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. Cyclops 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, Fias. 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 C. 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, Fiaes. 12, 13. Fischer ’51; Lilljeborg ’53 (quadricornis); Claus ’57 and ’63 (brevicaudatus, and fur- cifer); Sars ’63 (scutifer, abyssorum, and strenuus); Lubbock ’63 (brevicaudatus, ani clausii); Fric ’72 (brevicaudatus); Uljanin ’75 (vicinus, and fedtschenkoi); 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; Brady ’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 short, 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 antennez 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. 2 spines. ex. 1 seta. Outer ramus ; ap. 1 spine, 2 sete. Inner ramus 4 ap. 1 spine, 1 seta. in. 3 sete. in. 3 sete. THIRD 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. 3 sete. FOURTH Foot. ex. 2 spines. ex. 1 seta. Outer ramus { ap. 1 spine, 1 seta. Inner ramus jap. 2 spines. in. 3 sete (4 sete ?) in. 2 sete. The only difference of importance between the two species seems to be the shorter antenne of C. vicinus. ENTOMOSTRACA OF MINNESOTA. 10L 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. seutifer and C. abyssorum, should be regarded as synonyms for ©. strenuus. 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 ’801, 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 C. 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 bis 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 furea, 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. Furea as long as the last three segments, the width of the rami about one-seventh of their length. The inner of the two longer sete 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 Jarge spine and a few small ones a little beyond the middle of the outer surface, and a vertical comb of small spines 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 {se 1 spine, 1 seta. in. 2sete. in. 3 sete. SECOND FEET. ex. 2 spines. ex. 1 seta. Outer ramus |p 1 spine, 1 seta. Inner ramus {8 1 spine, 1 seta. in. 3 sete. in. 3 sete. THIRD FEET. ex. 2 spines. ex. 1 seta. Outer ramus | 8 1 spine, 1 seta. Inner ramus i 1 spine, 1 seta. in. 3 sete. in. 3 sete. FOURTH FEET. ex. 2 spines. ex. 1 seta. Outer ramus {8° 1 spine, 1 seta. Inner ramus {se 2 spines. in. 3 sete. in. 2setz. 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 setze, 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 sete, 1.33 mm., greatest depth a trifle less than one-third the length of the cephalothorax. Yellowstone lake, Great Lakes, ete. O. 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 (. pulchellus. It also has much shorter stylets and differently propor- tioned antennze, 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., antenne 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 (thomas?) 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 furca, and but two well-developed caudal sete 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 furca; the next in length less than half the longest. The armature of the legs is as follows: FIRST FEET. ex. 1 seta. ex. 1 seta. Outer ramus {sp lspine 2 sete. Inner ramus lo 1 spine, 1 seta. in. 2 sete. \in. 3 sete. SECOND FEET. ex. 2 spines. ex. 1 seta. Outer ramus {tp 1 spine, 1 seta. Inner ramus {0 1 spine, 1 seta. in. 3 sete. in. 3 sete. ex. 1spine. ex. 1 seta. Onter ramus |p *2 spines, 1 seta. Inner ramus | ap. 1spine, 1 seta. in. 3 sete. in. 3 sete. FouRTH FEET. ex. 1 spine. ex. 1 seta. Outer ramus {se *2 spines, 1 seta. Inner ramus ap. *2 spines. in. 3 sete. in. 2 sete. —_— Se eg tet a A THIRD FEET. * 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 set at its blunt 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. *Cycleps forbesi Herrick. Forbes 793 (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 furea 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 set are reduced to short subequal spines about twice as long as the ramus is wide. The other set are slender, plumose, the inner nearly twice as long as the outer. The antenne 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. a ENTOMOSTRACA OF MINNESOTA. 105 First FEET. ex. 1 spine. ex. 1 seta. Outer ramus jap. 1 spine, 1 seta. Inner ramus ap. 1 spine, 1 seta. in. 2 sete. in. 3 sete. SECOND FEET. ex. 1 seta. ex. 1 seta. Outer ramus + ap. 1 spine, 1 seta. Inner ramus ap. 1 spine, 1 seta. in. 3 sete. in. 3 sete. THIRD FEET. ex. 1 spine. . ex. 1 seta. Outer ramus jap. 2 spines, 1 seta. ~ Inner ramus ;ap. 1 spine, 1 seta. in. 3 sete. in. 3 sete. 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-jointed, 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, Fias. 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 (anuulicornis, 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 86 (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. Sets 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: A 106 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. ex. 2 spines. ex. 1 seta. Outer ramus jap. 1 spine, 1 seta. Inner ramus iP 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 setz. Color bluish or banded, the antennze especially banded on the fifth to sixth and twelfth to fourteenth joints. * Cyclops signatus var. coronatus. PLATE XV, Fias. 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, Fies. 1-7; XX XIII, Fies. 1, 2. 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 receptacnlum 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 C. 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 coronaius from tenuicornis have been made, and, while some possible sources of error unfortunately crept in, yet I am morally convinced 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 ©. 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 gréssten 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. It is hoped to furnish conclusive evidence on this head soon 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. BEATE XeViL, Pies, 10! ote Sars ’63; Herrick ’84; Schmeil 791 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 C. 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 setze 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. 1 spine, 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 |S 1 spine, 1 seta. Inner ramus |" 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 mm.,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. coronatus 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. wa 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 Tiimpeln 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 larvz) 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 to 1.1mm. 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 antennze 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 antenn are 17-jointed. The feet are all three-jointed and armed as follows: First Foor. ex. 3 spines. ex. 1 seta. Outer ramus {sp 1 spine, 1 seta. Inner ramus | 2 spines, 1 seta. in. 3 sete. in. 2 sete. SECOND Foor. (ex. 3 spines. ex. 1 seta. Outer ramus ~ ap. 1 spine, 1 seta. Inner ramus |e 2 spines. in. 4 sete. in. 1 spine, 2 sete. ENTOMOSTRACA OF MINNESOTA. 109 THIRD Foot. ex. 2 spines. ex. 1 seta. Outer ramus ; ap. 1 spine, 1 seta. Inner ramus 4 ap. 2 spines. in. 4 sete. in. 1spine, 2 sete. FouRTH Foot. ex. 2 spines. ex. 1 seta. Outer ramus |S 1 spine, 1 seta. Inner ramus {8 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 setz are rather short while the inner seta is nearly as long as the outer median. A|J 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 ecapilliferus Forbes. PLATES VI, Fig. 13; XXVIII, Fiaes. 1-4. Forbes ’93. 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 setve, and 16 jointed antenne bearing several very long sete. The abdomen, with candal furea, 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 te last. The caudal rami are twice the length of the last segment and one fourth as broad as long. The lateral seta 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 set upon the first, third, tenth and fourteenth segments. Terminal sete 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 ae rae 5 ss £ 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. {ee 2 sete. Outer ramus + ap. 1 spine, 2 sete. Inner ramus ; ap. 2 sete. in. 3 sete. lin. 1 seta. SECOND FEET. ex. 2 spines. ex. 3 sete. Outer ramus jap. 1 spine, 2 sete. Inner ramus j 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. FouRTH FEET. ex. 2 spines. ex. 1 seta. Outer ramus ; ap. 2 sete. Inner ramus + ap. 2 sete. in. 4 sete. in. 2 sete. 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. gq f *Cyclops insignis Claus. PLATES XXII, Fies. 11-14; X XIII, Fas. 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. ubbockii Brady with the brack- ish varieties of C. bicuspidatus = OC. 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 ©. strenuus. ‘The lateral apical sete 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 C. strenuus. Fifth foot exactly as in ©. strenuus. Length 2.5 to 5.0 mm, ENTOMOSTRACA OF MINNESOTA. i A il 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 after such division. Against the suggestion he urges, (1) thatthis form is notsimply 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 « priori arguments. Respecting C. lubbockii Brady, whether it should be considered an atavistic form of C. strenwus 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 XY, Fias. 8-11; XIX, 2-5; XXVI, Fie. 10; X XIX, Fies, 17-19. Fischer 751; Lilljeborg ’53; Claus ’57 and ’63; Sars ’63; Lubbock ’63; Heller ’70; Fric "72; Hoek ’78; Brady ’78 (serrulatus var. wontanus, and serrulatus); Uljanin "75; Herrick ’82, and ’84 (serrulatus var. elegans, and serrulatus); Rehberg ’80 (agilis); Cragin ’83 (pectinifer); Daday ’85° (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 Eastern 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 GO é ia fee ae - s ay 112 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. cephalic margin of the last thoracic segment, tending to assume dur- ing life the form of arude 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 antenne. 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; -dosetas Outer ramus | 2 sete. Inner ramus {an 1 spine, 1 seta. in. 3 sete. in. ~3 sete. SECOND AND THIRD FEET. ex. 3 spines. ex. 1 spine. Outer ramus jap. 1 spine, 1 seta. Inner ramus 4 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 antenne 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 V.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 mia.). 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- cal 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 ENTOMOSTRACA OF MINNESOTA. 113 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 antennze 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 distine- 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 789; Lande ’99; Richard ’91; Schmeil ’91 and ’92., This form is so close to C. 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 ©. 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 XXVI, Fiaes. 1-8; XXX, Fia. 1. Herrick ’82, ’84 and ’87; Cragin ’83 (magnoctavus); Brady ’91 (magnoctavus); Turner 792; 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 aspecimen 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 sete 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 + ap. 2 sete. Inner ramus 4 ap. 2 sete. in. 3 sete. in. 3 sete. SECOND AND THIRD FEET. ex. 3 spines. ex. 1 seta. Outer ramus jap. 1 spine, 1 seta. Inner ramus ; ap. 2 sete. in. 4 sete. in. 3 sete. FourRTH Foor. ex. 2 spines. ex. 1 seta. Outer ramus 4 ap. 1 spine, 1 seta. Inner ramus © 1 spine, 1 seta. in. 4 sete. in. 2 sete. The fifth foot is small, one-jointed, and bears three small set. 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-saes are appressed and contain four or five ova in the first state and a few more in the adult. The two 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 pelagic, 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 ©. 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 set; 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 @. viridis in many points. Found only in Scan- dinavia. Cyclops crassicaudis 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. LHxterna] apical seta longer than the internal, both short; median set long. Antenne of the first pair 12-jointed, scarcely longer than the first segment. Swimming feet short and thick, spines and set short; the interior apical spine of the last joint of the inner ramus of the fourth 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, Figs. 12 AND 13; XXX, Fies. 2-8. Sars 763; 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 ——=-——-x-—-—~~=-, sete of moderate length. Feet with the fol- lowing formula: FIRST FEET. ex. 3 spines. ex. 1 seta. Outer ramus | 2 sete. Inner ramus {iP 1 spine, 1 seta. in. 3 sete. in. 3 sets. FourRTH Foor. 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 C. 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 0.25, >, . x F e c % 4 * a. ENTOMOSTRACA OF MINNESOTA. 117 Cyclops gracilis Lilljeborg. PLATE XIX, Fiaes. 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 setee 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; formas LL ===. Fifth foot with a broad basal segment and a cylindrical terminal 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, Fies. 6-9. Fischer 53; Claus ’63 (minutus); Heller ’63 (minutus); Daday ’85° (frivaldszkyi); Sostaric ’88; Schmeil 792. 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 sete short, equal, median sete 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° (pygmzeus, 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 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 ecrustacea, 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 ©. adolescens, more beyond. The original description of Cyclops affinis Sars is here repeated, and it justifies the doubt which, in the absence of authentic 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 ©. 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 ©. affinis is _~U_= 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 C. 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 antennse 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 larvz 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 ©. 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 C. 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 set# 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 ©. viridis this is especially liable to occur, because of its stagnant stations. The color changes with the rest and the change 124 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. may be noticed in the same pool during the progress of the seasons. In these eases, 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. It is obvious that they are quite different from the sporadic appearance of sexually functional larve, 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. le ie ieee a Be | ee, a ay 2 al ac” 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; maxille 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 CANTHOCAMPTINA, 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 ina 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 in a process below, which bears besides a long hair a peculiar blunt . * A re and 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 antennz 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 ceca 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 sac 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 foree-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 crustace, 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 asin 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 antennz, 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. 9“) 5) 76... a, 2. e) Motos, 131 tt Stylets short, oval. . . at apthat: an -AImoGisensis; 131 If. Inner ramus of the fourth foot three- -jaamted. a. Maleantennanorma).. . . Sos) 4s hibernicus; 133 6. Male antenna reduced, hooked at ‘the oad hy Sota ate palustris, 133 [Not noted in the key are: tenuicaudis, 129; northumbricus var. americanus, 130; borcherdingii, 134; minnesotensis, 134. ] Canthocamptus elegantulus, C. mareoticus and C. horridus are uncer- tain, probably referred to the wrong genus. C. stromii Baird (= Dacetylopus stromii), C. rostratus Claus (= Stenhelia ima). C. vire- scens, C. linearis, and C. roseus of Dana, are marine Harpacticide of uncertain affinities. C. minutus of Claus is not sufficiently described, but appears to be the earlier condition of C. minutus Mueller (C. sta- phynalis Jurine). * Canthocamptus gracilis Sars. Is elongated linear, with the abdominal segment smooth. Caudal stylets long and slender; external caudal seta about one-fourth the inner. All the feet with two-jointed inner rami; outer branch of fourth foot longer than the others, inflexed; basal process of fifth foot slightly expanded. Length 1.0 mm. (* Canthocamptus tenuicaudis Herrick.) PLATE XXIX, Fies. 15 and 16. At Decatur, Ala., was found a species of Canthocamptus which is different from any American species, and seems in many points nearest the above, but, unfortunately, only a hasty sketch could be made at the time, and the notes are insufficient to define it. The form is not remarkably slender; the first and second abdominal segments are very large. The caudal stylets are slender and elongated, the inner seta being very long and curved, while the outer is quite short. The anal plate is covered with hairs only. The antenne are normal, of moderate length, and the fifth foot has but a narrow process at the base. If this form be worthy a distinctive name, it may be called Cantho- camptus tenuicaudis, } Distinguished from the following by the presence of only three spines on the process of the basal joint of the fifth foot. Lh a EY Le ts ‘ tes 2a oS " See ee bay «: - , ’ inh! = a ( J : Paty: : ee : q 130 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. Canthocamptus brevipes Sars. This small form is almost certainly the young stage of some other species; yet I transcribe the description: ‘““Corporis forma et magnitudine C. pygmeo non dissimilis. Segmenta abdomi- nalia vero postice magis attenuata seriebusque aculeorum destituta. Rami caudales elongati duplo longiores quam latiores, setis apicalibus brevisculis parumque diver- gentibus, exteriore dimidiam longitudinem interioris nonattingente. Operculum anale absque dentibus. Antenne 1-mi paris breves, articulis ultimis duobus in unum con- fiuentibus articulum. Pedes natatorii brevissimi, ramo exteriore intus setis destituto, interiore biarticulato in pedibus 1-mi paris longitudinem exterioris sequante, in sequentibus multo breviore. Pedum 5-ti paris articulus basalis intus in processum foliiformem, sat magnum et angustatum, articulum ultimum elongato-ovatum aliqu- anto superantem, exit. Color albidus. Longit. parum supra 3 mm.”’ Canthocamptus crassus Sars. Robust; segments margined with pectinate bristles. Caudal stylets oval, contorted, constricted at the base. Antenne thick, densely covered with long sete. Fifth feet with long sets; basal process rather small. All the feet excepting the first, with biarticulate inner rami. Length 0.75 mm. Canthocamptus trispinosus Brady. PLATE L, Fie. 6. This species with the last and next has all the feet save the first with biarticulate inner rami. Very near the next, from which it differs in the form of the fifth foot of the female, which has the basal process smaller, bearing only three spines, while the next has six, the second joint being longer and narrow. The male is unknown. Not yet identified in America. Canthocamptus northumbricus Brady. PLATE XXIX, Fie@s. 20-22. Body robust; antenne long as first segment, nine-jointed; mandi- bular palp minute. In the male the inner branch of the third foot is three-jointed and dactylate, as in C. minutus. * Canthocamptus northumbricus Brady. Var. americanus Herrick. PLATES XXIX, Fias. 6-14; XX XIII, Fras. 3-5. One of our most common species is very near the English form; so near, in fact, that I dislike to remove it from it. A few points of divergence, however, may be mentioned. The form and proportions are much like those of C. minutus. The head is large and ends ina prominent bent beak. The antenne are ne ae ENTOMOSTRACA OF MINNESOTA. 181 rather long and slender and have a well-marked flagellum. (Brady figures no flagellum.) The palp of the antennule is as in ( minutus. The mandibular palp is small. The first pair of feet normal, rather small; all the other swimming feet with two jointed inner rami, save in the case of the male third foot. The fifth feet are exactly as figured by Brady, save that there is a prominence or tooth of the basal seg- ment near the point of attachment of the terminal joint which is quite long. The sensory area of the head is oval and pointed. The male antenna has a long flagellum, not, as figured by Brady, a very short one. The egg-sac is very large, oblong. The animal seems to fall short of the size of the English species, though measuring upwards of 0.65 mm. Our form is very well distinguished from any other spe- cies. It is found in Lake Minnetonka, Lake Calhoun, and elsewhere. * Canthocamptus minutus Mueller. PLATES XLVII, Fies. 7-21; L, Fies. 7, 8. Monoculus staphylinus—Jurine. Canthocamptus minutus—LilJjeborg, Baird, Sars, Uljanin, Brady, Herrick. Canthocamptus staphylinus—Claus, Fric. Canthocamptus minutus var. occidentalis—Herrick. A well-known species which has been frequently described and seems quite circumpolar in its distribution. First mentioned from America in a paper by the writer in 1878 A pretty full description will also be found in the author’s Types of Animal life. A very abundant species, frequent in muddy pools, but somewhat variable in abundance. It may frequently be found in great numbers in winter. [The following description, compiled from Types of Animal Life, is inserted here for the convenience of those who are likely to use this report asa manual. H. F. N.] Length about 1.0 mm. Antenne a little longer than the first seg- ment of the body; first three joints profusely covered with hairs; fourth joint more slender than the preceding and terminating in a process below, which bears, besides a long hair, a peculiar blunt bristle; fifth joint shorter than the rest; the remaining three joints are spined at definite points. The antenne of the male are geniculate; the three basal joints are short while the three following joints are coalescent and are followed by a hinge joint of two elongated segments. The antennules are two-jointed; the basal joint bears a two-jointed palp; the terminal joint is covered with spines; at the end there are three longer and curved spines, jointed in the middle, and the upper furnished with three small spines at the curve. 9 ——-. ar ee 132 GEOL. AND NAT, HIST. SURVEY OF MINNESOTA. The mandible is a flattened toothed plate, bearing a two-jointed palp on one side and a blunt process on the other. The first maxilliped is short and bears claws and spines. The second mavxilliped is simple, three-jointed, and has a claw at the end. The first pair of feet are biramose, each ramus being three-jointed; the outer ramus is shorter than the inner. The inner ramus of the fourth foot is two-jointed. . In the male the inner ramus of the third foot is modified into a sort of grasping organ. The fifth feet are com- posed of two flat joints, larger in the female than in the male. The first abdominal segment of the male carries a pair of three- spined processes. The last abdominal segment bears two stylets, each terminated by two long sets, one being longer than the abdomen and longer in the male than in the female. * Canthocamptus illinoisensis Forbes. PLATE XXIX, Figs. 1-5. This robust and pretty species was first taken near Minneapolis by Mr. A. W. Jones, a student of the University, who found it in a peaty ditch. Forbes’ description is appended. ‘‘Length 1.0mm. Head and first segment united; five abdominal segments in male, four in female. The suture between the first and second segments is not wholly obliterated above in the female. ‘“‘Last abdominal segment is deeply and acutely emarginate. Branches of furca as wide as long, inner bristle plumose, a little longer than abdomen; outer plumose only on outer side, about half the length of the inner. Thesecond to fifth abdominal segments have each a row of spinules along ventral portion of posterior. ‘‘Male with anterior antennze composed of seven joints, the fourth joint very short. The front outer angle of the third is produced, the blunt process bearing three long bristles surrounding a slender olfac- tory club which is as long as the three following joints. The penulti- mate joint bears a strong spine or slender appressed process at the middle of its posterior margin. The five outer joints constitute the grasping organ. The posterior antenne bear five long bristles at tip, three of which are made prehensile by the occurrence of from eight to twelve short articulations in the middle of the hair, allowing it to be bent forward. At the base of these articulations on the outer bristle are two short spinules. Two nearly longitudinal rows of five or six strong, short spines each appear on the under surface of the outer joint of the antennule. The secondary flagellum, borne as usual on the middle of the basal joint, is not articulated, and bears four long bristles, two terminal and two on distal half of inner side. The out- line of the mandible is exactly like that figured by Claus, but it bears ENTOMOSTRACA OF MINNESOTA. 133 about ten teeth, the upper thick and blunt, the inner sharp, slender and longer. Several are notched at tip. The lower angle bears a long simple bristle. Mandibular palpus two-jointed, second joint with three long terminal hairs and a shorter spine attached at basal third of anterior margin, jointed at base and directed towards tip, like a dactyl. The maxilla and maxillary palpus are searcely to be distin- guished from those of C. staphylinus. ‘The first maxillipeds are three-lobed, the outer lobe constituting a long, strong claw. The second and third are about one-third as long as the first, and bear each one strong simple spine and one weak branched hair. The inner lobe is widest, about two-thirds as wide as long. The dactyl of the posterior maxilliped is spinous on its inner edge, and the same edge of the hand is ciliate and bears a short, stout, sparingly plumose bristle at its base, just beyond the tip of the closed dacty]l. The width of this joint (the second) is nearly half its length. ‘“‘Basal joint of inner ramus of first pair of legs nearly or quite as long as outer ramus, the second wider but only half as long as the third, and obliquely truncate. Inner ramus of third pair of legs in male is three jointed [the outer two-jointed]*, chelate. The finger is ovate, truncate, terminating in two long plumose hairs. The dactyl is linear, curved at base, and twice as long as finger. The inner ramus of the fourth pair of legs is about half as long as outer, two- jointed, basal joint short, terminal joint about as long as middle joint of outer ramus. The fifth pair of legs is best developed in the female. In the male the length is not over one-third the width. The basal portion bears three plumose hairs on its very broadly rounded ante- rior margin, of which the innermost is longest. The outer plate is nearly orbicular and bears five spines on its terminal margin, of which the second from the internal angle is the longest. Genital plates, found in male at posterior border of first abdominal segment, beneath, are Short, slightly expanded internally, with internal angles rounded, and externally bear three subequal bristles, jointed at base, the inner largest and strongest and semi plumose. The antenne of the female are eight jointed, extending backward to the first free segment. The basal joint of the fifth pair of legs is subelliptical in outline, with the basal half produced externally into a broad, triangular process which bears the second joint on its posterior margin. The free end of the basal joint bears six large plumose bristles, of which the inner is long- est. The greatest width of the joint is nearly equal to its greatest length. The second or outer joint is ovate, subtruncate, spined on each margin, and bears four plumose bristles at tip and one at the middle of its outer margin. Its length is about twice its breadth.’’ * Evidently a misprint, for it is the inner ramus which is chelate. 134 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. Canthocamptus hibernicus Brady. PLATE L, FIGS. 3, 4. A small species differing from all others save the next in having a three-jointed inner ramus of the fourth foot. ‘“ Anterior antennz of the female slender, eight-jointed, about as long as the first body segment, and much like that of C. minutus. In- ner branch of the second antenna very small, one-jointed. Posterior foot-jaw having a broad hand armed with a long apical claw. Inner branch of the first pair of feet scarcely twice as long as the outer; first joint longer than the entire outer branch, and nearly twice as long as the united second and third joints, both of which are extremely small. Inner branches of the second, third and fourth pairs shorter than the outer, and three-jointed, the first joint being very small. Inner seg- ment of the basal joint of the fifth pair of feet in the female elongated, fringed, bearing two long and three short apical set; second or outer joint sub-ovate, finely fringed internally; externally bearing six long marginal sete. In the male the limb is smaller, the basal joint short, broad and having six short sete of equal length; second joint nearly like that of the female. Caudal segments somewhat longer than broad; inner seta about twice as long as the outer; anal operculum denticulate. Length 0.65 mm.’’ Not found in America. Canthocamptus palustris Brady. PLATE L, Fia@. 5. A brackish-water species about 0.9 mm. long, found in a number of places in the British Isles. The species presents several anomalies. The antennz of the female are eight-jointed; those of the male robust, the last joint forming a hook. The first four pairs of feet have both branches three-jointed; the fifth pair in the female are two- jointed, with a short and broad basal joint, the second joint being sub- ovate, bearing five long apical sete; in the male the fifth pair is obsolete, being reduced to a minute setiferous lobe. Caudal segments short, bearing two principal sete, the outer half as long as the inner. Canthocamptus borcherdingii Poppe. Poppe ’89. The female is 0.64 mm. long. Caudal margins of cephalothoracic segments unarmed, but in the middle of each segment a transverse line of spinules. Abdominal segments spined beneath. Anal operca- lum with eleven teeth. Stylets short with two short unpectinate sete, the inner half as long as the body while the outer is one-fourth. An- tenn eight-jointed, shorter than the first segment. Mandiblar palp ENTOMOSTRACA OF MINNESOTA. 135 short, one-jointed, armed with three short sete. The branches of the first foot are equal, the outer three-, the inner two-jointed. The joints of the latter are equal and spined laterad. The first segment bears on the mesal aspect a short seta, the second a short seta, and at the end a long seta and stout spine. The apical segment of the outer ramus bears a spine and at the apex a spine twice as long as the lateral one, a curved seta and a straight seta. The inner rami of the second to fourth feet are two jointed. The fifth feet are exactly like Brady’s Attheyella cryptorum, which Poppe thinks may have arisen by degenera- tive modification of this species. The fifth feet of the male are two-jointed; the inner portion of the first segment is less developed than in the female and bears two short pectinate bristles. The oval apical segment has six setz.. The two inner ones are short and pectinate, the next is long, the next is shorter and finally two simple sete. The inner ramus of the third leg of the male is three-jointed and is longer than the second joint of the outer. The first joint is very short with a small seta internally, the second segment is twice as long with a stout, curved pectinate seta, the apical segment is unspined but bears a long pectinate seta. Length of male 0.544 mm. Occurring in various fresh-water lakes of northern Germany. * Canthocamptus minnesotensis Herrick. PLATE XXII, Fiaes. 1-6. Since the manuscript of this genus was finished, a small species has been found which seems undoubtedly distinct from any of the above. A single pair were taken in a gathering from Bassett’s creek contain- ing C. minutus in abundance. Unfortunately the characters of the swimming feet are not certainly known, but they were apparently all three jointed save the last. The antenn are very short and thick, eight-jointed, with a long flagellum; the antennules are of the usual form, and the mouth parts rather large. The first pair of feet have the two rami of nearly equal length. The form is moderately elongate. The caudal stylets are very short, quadrate in outline and well armed with spines. The fifth foot of the female has four long and two short spines on the inner lamina, and the terminal joint has five unequal spines. In the male the fifth foot has two spines on the lamina and six on the second joint, one being a small bristle. The male antenna is of peculiar form. The teeth of the anal plate are large and emar- ginate (see Fig. 4). 136 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. The swimming feet are all armed with very strong spines, aside from the usual quota of spines at the end of each joint. Length 0.65 mm. GENUS ATTHEYELLA Brady. This genus, the diagnostic characters of which have been above indicated, contains three nominal species. It is quite difficult to say what differences exist between Sars’ Canthocamptus pygmeus. and Attheyella spinosa. Brady did not seem to recognize the fact that his diagnosis included that species. The third species is the blind A. eryptorum of Brady, which it is interesting to compare with the blind Bradya limicola of the coast of the Gulf of Mexico. GENUS MARSHIA Gen. nov. Allied with Attheyella. Inner branch of first foot three-jointed, scarcely elongated, barely subprehensile. Second and third feet with outer ramus two-jointed, short. Fourth foot with minute one-jointed outer ramus and three jointed inner ramus. Fifth feet one-jointed. Antenne six-jointed, the fourth joint with a slender hyaline process longer than the end of the antenna. Second antennz without obvious palpus, prehensile. Mandiblar palp simple? First foot-jaw with an uniciliate papillose palpus. Second foot-jaw with a long uncinate special joint. Antenne ofthe male strongly modified. Habit, fresh or brackish waters. . *Marshia albuquerquensis sp. n. PLATES XXXI; XXXII, Fires. 1-5. Body with ten obvious segments, with the aspect of Canthocamptus. Antenne short, six-jointed. The proximal joints enlarged and spinous; second also tumid, with three or more cilia; third joint longer; fourth with a long seta and still longer flagelium; fifth joint very short; apical joint elongate bearing about ten sete. Antennules short, pre- hensile, with four geniculate sete apically and several short spines, especially a transverse series of sharp teeth on the dorsal aspect. Jaws with six sharp teeth. Anterior maxillipeds with a minute uni- setose palp and three processes bearing curved spines. Posterior Note.—C. jrontinalis Rehberg. This author seems to have parted with his usual acumen in the remarks upon this species. After describing a Conihocamptus with the inner ramus of the first foot “reichlich doppelt so laug wie die beiden Grundglieder des Aussenasts,”’ he draws a moral on the muta- bility of genera from the fact that Brady founded the genus Aftheyella ‘auf grund der Eingliede des innenastes am fierten Fusspaare und einer derartigen Bildung des ersten Fusses, wie er bei C. frontinalis beschrieben ist.” Brady says (Brit. Copepoda, p. 58): “Inner branch of first pair of feet scarcely at all elongated, and either two- or three-jointed,” etc. The distinctive characters being the one- or two- ointed second and third feet and the one-jointed inner ramus of the fourth foot, it is doubtful if C. rontinalis is really new. ENTOMOSTRACA OF MINNESOTA. 137 maxillipeds with a long claw longer than the preceding joint. First foot with the outer ramus nearly as long as the inner, two-jointed, bearing at the apex three pectinate setze. The basal joint bears a pec- tinate seta externally and a spine internally. The inner aspects of all the joints of both rami are spinous, the outer setose. The outer ramus of the second foot is two-jointed and has one pectinate seta apically, one spine internally and one spine-externally, while the corresponding segment of the third foot has two pectinate sete apically and one internal seta and two external spines. The fourth foot has a minute one-jointed outer ramus bearing one long pectinate seta and a short external spine. The fifth foot seems to consist of one piece, armed as follows: Externally a conical projection near the base with a long simple seta, outer apical lobe (= the homologue of second joint) with five sets, the second and fourth of which are longer and pectinate; the inner apical lobe bears six (or five) sete, all but the innermost being pectinate. The two lobes are separated by a simple incision, and repeated examination showed no indication of any segmentation in either sex. The abdomen is very slender, and, like the thorax, its segments are all ornamented caudad with a series of spines or teeth. Stylet two and a half times as long as wide, with one or two small spines externally one third the length from the base and one longer spine near the middle of the inner margin, which is ciliate. The two median apical setz are fused at the base and the inner is three times as long as the outer, which is twice as long as the stylet. ‘The inner apical seta is short, the outer obsolescent. In the male the antenna is reduced to a thick tumid member with the third and fourth segments greatly enlarged. The apical segment is furnished with three hook-like claws. Flagellum slender, of uni- form diameter. Fifth foot has on the outer apical lobe four sete and a small spinule, and on the inner three non-pectinate sete. Caudal stylet greatly elongate, over four times as long as wide and nearly twice as long as the preceding segment. Marshia brevicaudata sp. n. PLATE XXXII, Fics. 6-13. The second species of this genus at present known may be described comparatively. Similar to M. albuquerquensis in most respects, but differing in a few points so far as known. The caudal stylets are short, about twice as long as broad, the longest seta being seven times the length of the stylet, while the outer median seta is twice anda half as long as the stylet. These sete are not fused at the base. In the male the difference between the species is greater. The proportions of the stylet being the same as in the female, but the longest seta is ee ee east ; 138 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. nine times as long as the stylet. The fifth foot of the female nearly as in the previous species, but the proportions of the sete differ. The fifth feet of the male are like those of W. albuquerquensis. The antenne of the male seem to be different. In WM. albuquerquensis the apical seg- ment is larger and the flagellum is long and of uniform width, while in the present species the flagellum is short and clavate. The swim- ming feet seem similar. Length of male 0.56 mm., length of first seg- ment 0.15 mm., length of stylet 0.04 mm., length of longest seta 0.28 mm. to 0.54 mm. The stylets in the female of JZ. albuquerquensis measure 0.072 mm. in the female and over 0.08 in the male, the longest seta being 0.37 and 0.42 respectively. It must remain for larger experience to determine the value of these distinctions, which rest on comparatively few individuals in the case of M. brevicaudata. 1 gece ah bea! 23 f CLADOCERA OF MINNESOTA BY CC. i. BMERRICEK : ORDER CLADOCERA. This very extensive group contains a variety of types, but there are sufficiently evident connectlng links uniting the extremes of structure. The Gymnomera which, following the usual custom, we include here, stand distinct from the other groups, yet have suffic- iently evident cladoceran affinities. It is very unfortunate for etio- logical speculation that this the only truly marine group should stand thus isolated from its fellows. According to the notions at present prevailing, the Phyl/opods stand nearest the primitive type of crusta- cea. There are unmistakable hints at an early origin for that group, and not less evident are certain analogies with both Cladocera and Copepoda. There has, however, recently been made an attempt to derive the Phyllopods fiom an original cladoceran stem with, as we think, some- what unsatisfactory results. Do we not rather see in both groups two like phases which may be looked upon as incidental and comparatively trivial? The shelled and the shell-less phases appear in both. The most closely shelled Phyl/opod is unmistakably nearer Branchipus even than any of the Cladocera. It would seem that the brief and imper- fect embryonic nauplius condition of the latter sufficiently indicated their later origin. Again, no fanciful analogy can unite the Ostracoda with the Lynceide. We know of no recent discoveries casting dis- credit on the remark of Balfour: ‘‘The independent origin of the Ostracoda from the main crustacean stem seems probable.’’ Professor Packard says:** ‘““We imagine that when a permanent body of fresh water became established, as, for example, in perhaps early Silurian times, the marine forms carried into it in the egg-condition, possibly by birds [sic?] or by high winds, hatched young, which, under favorable con- ditions, changed into Sida, Moina and Daphnia-like forms. The Clad- _ocera are, then, probably the more generalized forms, from which the Phyllopods, at this time, and probably ever since Devonian times, par excellence a fresh-water assemblage of forms, took their origin. What- ever affinity there may be between the shelled Phyllopods and the Ps “A Monograph of the Phyllopod Crustacea,” etc., X7/ih Annual Rep. U. S. Geol. and Geog. Surv. err. 142 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. Cladocera, it would seem that the evidence is conclusive that the latter group is not the direct continuation of the line of development inau- gurated by an ostracode ancestor. As shown beyond, the present centre of the group seems near Moina, with indications of a divergence from this rather generalized type, especially of degradation and het- eronomy on the side of the Lynceids. It seems at the present time that more might be accomplished for etiology by a careful study of such groups as the present, in which are a variety of closely allied forms, than by the attempt to join widely separated groups. When we shall have seized upon the latest eddies and mapped their direction, it may become possible to combine the indications in such a way that lines of divergence thus traced accurately through some small part of their course may be produced backward to their intersection. This, then, is our present duty—the accurate mapping of minute districts and the careful noting of any moving straws competent to indicate movements in the vast complex of vitalized nature. We conceive the Cladocera to have had a com- paratively recent origin, and to express the culmination and retrogade development of a plan of structure first differentiated after the appear- ance of clear bodies of fresh water. All the species save a very few are confined to inland waters. Accepting the above mentioned theory, the Sidide will oceupy the first place as departing least from the type from which the whole group sprang, while it is connected by the genus Daphnella with the Daphnide. The Daphnide, beginning with Moina, find their ultimate development in some monstrous forms of the genus Daphnia, bat pass into the Lyncodaphnide by way of Macrothrix. The links uniting all these minor groups are very obvious. Our own ideas of the relationships among the Calyptomerous Cladocera are expressed in the accompanying table. This table is to be consid- ered a projection of a portion of a genealogical tree, seen from below, in which the genus Moina forms the arbitrarily chosen fixed point. The heavy dotted line is imagined as directed downward vertically. That branch rising toward the top of the page is growing obliquely upward. The Daphnidw are represented as expanding upon the same plane as Moina, and the Lyncodaphnide extend diagonally downward, producing the Lynceid branch. The Bosminide spring from the stem at a lower point.* The Cladocera or Daphnoidea are characterized by the more or less leaf-like feet and the lamina of thin chitine which incloses the greater * Nore.—To adapt the diagram to the theory that the Lynceide@ are the progenitors of Cladocera, it is only necessary to revolve the imaginary line to the right, till it coincides with the axis of that family, The question mark may be understood to indicate that the source of the pivotal group, Moina, is uncer- tain. The author must confess that his inclination is toward a belief that the line culminating in the Daphnide diverged from a group of organisms resembling Phyllopoda, more definitely, resembling Limnetes. There isa very remarkable resemblance between the larva of Limnetes and Bosmina, The lateral spines of the former are, as will be shown, true homologues of the antennules of Bosmina. ‘The later origin of the P/iyllopoda io their present form may be well admitted. Boag ee hee * age eT ON eS Se ’ EEE | ENTOMOSTRACA OF MINNESOTA. 143 Limnosida Sis Sj Latona 2 Sida Pseudosida b= Holopedidz ve oe we ere i ~ aS \ t a gee a —_ ox \ Pe SS as ‘--”_ Daphnella ~ Ve SN if aoa ae a | Simogephalus (ry ie a ies M oO! NA----Ceriodaphnia es ‘Daphnia Viz ! ¢ yp ¢ S > ‘ . Be > ENTOMOSTRACA OF MINNESOTA. 215 the posterior margin has a series of long sharp teeth; the mandibles are nearly completely exposed by the arched anterior margin of the valves. The labrum, in this species, is an odd link between that of the Daphnide and Lynceide. The basal segment is greatly enlarged and is sub-triangular in outline, with a movable lip attached to the inner free face; the typical daphnoid structure is preserved, but the enlarged salient angle of the basal portion shows how the transition to the great triangular labrum of Alona, etc., is made. In young specimens the head is proportionately larger, the antennules are broader at the tip, and the dorsal outline is less convex; the marginal spines of the valves are also proportionally larger, as are the appendages of the first and last pairs of feet. This is one of the largest species of the genus, 0.75 mm. being the length. This is very close to M. rosea but seems distinct. This form is quite commom about Minneapolis, Minn., but is not yet noted elsewhere in America. *Macrothrix pauper Herrick. PLATE LVI, Fie. 4. This species is described from a single specimen from Lake Minne- tonka, and I can add nothing to the very meager notice given then. (Herrick ’82.) The body is broad and very narrow, the lower outline is angled and nearly unarmed; the pigment fleck and eye are small and approxi- mated; antennules very long and curved backward and outward; ab- domen short, ciliate below; claws short, ciliated. This female had a full complement of eggs but the antennz resemble those of a male. This is unusually interesting and should be rediscovered and studied; for there seems to be some affinity between this species and Bosmina, and it is probable that it requires to be distinguished generically from Macrothrizx. GENUS LATHONURA Lilljeborg. The form is oval; the head is curved more than in Macrothrix and the shell is more obtuse behind, sinuate below where it is beset with short spines anteriorly; first antenne long, straight; second antenne with five sete on each ramus; only four pairs of feet apparent; ab- domen short, prolonged upward to the insertion of the caudal stylet; male similar but smaller. rf oe teeny = 216 GEOL, AND NAT. HIST. SURVEY OF MINNESOTA. *Lathonura rectirostris O. F. Miiller. PLATE LVII. Koch ’35-’41 (Pasithea rectirostris); Zaddach ’44 (Daphnia brachyura); Lievin ’48 (Daphnia brachyura); Fischer ’52 (Daphnia mystacina); Lilljeborg ’53; Leydig ’60 (Pasithea rectirostris); Norman and Brady ’67; P. E. Mueller ’68; Schoedler 58 (spinosa); Birge ’78; Gruber and Weismann .’80 (Pasithea rectirostris); Herrick ’&2. 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 antennz are straight and long, with a sensory bristle near the base in front and two bristles athird from the 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 set 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 Wacrothrix 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. 7A by 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 witha large process. Post-abdomen much as in Wuacrothrix 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. VW. 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 set 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, Fic. 9; LIV, Fic. 4; LVI, Fie. 14. Acantholebcris dentata—Euren. Drepanothrix seligera—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 sete are chiefly used as pushing poles. The species has been taken in Denmark, Scandinavia, Eng- land and France as well as America. bo _— (9 63 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. GENUS ACANTHOLEBERIS Lilljeborg. Body more or less quadrangular, head triangular, acute cephalad, bearing the antennules at the front. Fornix slightly developed. Head searcely separated by a depression from the body. Antennules elongate, expanded apically. The three-jointed branch of the antennz has five sete, 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 0. F. Miiller. PLATE XLVI, Fias. 1-4. 0. F. Miller 1785 (Daphnia curvirostris); Schoedler ’46 (Acanthocercus rigidus); Lievin ’48 (Acanthocercus rigidus); Liljeborg ’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 sete. 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 antennze with no lateral setee; eye small, pigment fleck present; intestine twice con- voluted, expanded posteriorly, with anterior bnt no posterior cxeca, opening near the “‘heel”’ of the post-abdomen; post-abdomen large, triangular; terminal claws long, rather straight, with two accessory spines at the base. Ofryoxrus is, aS Was Suggested, a curious transition form linking the Daphnide with the Lynceide. re. 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 ceca, which is not the case in Lynceids, nor, indeed, in other Lyncodaphnide. The four-jointed ramus of the antennz 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 lvnceid 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 Lyncodaphnida; 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, Fias. 12-15; LVIII, Fies. 1-3; LIX, Fie. 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 antennz 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- _ 2 oe 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 oceurs 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 alg 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 JI. spinifer, on the other hand, swims freely till loaded up with old clothes and filth. This genus is also closely allied with the Lynceide. * Tlyoeryptus sordidus Lievin. PLATES LV, Fies. 6, 10, 11; LVI, Fias. 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 setz; post abdomen large, broad; terminal claws with two spines at the base; anus in the middle of the posterior margin, which is very heavily emi with spines; a os abdominal process is present, according to Kurz. There are no anterior ceca (my statement that P. E. Mueller de- scribed such cca was an error; see Notes on Cladoreca of Minnesota, p. 246). Length 0.78mm. 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. 221 * Tlyoeryptus spinifer Herrick. PLaATEs LV, Fias. 1-4; LVI, Fiaes. 18-19, 21. Herrick ’82, ’84, and ’87; Turner 793. The description given in my Final Report, etc., is very brief, and no comparisons were there instituted with the I. 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 I. 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 0.14mm. 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 be a “ye aa at we a ee i“ " Cr _ P ie *)' ) GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. 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 antenn 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 J. 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 sets, 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 zie the relation between the four species of this little known genus even clearer, if possible, the following comparative table is appended. ae I. agilis. Rhe shell moulted poriodicall y:. :...- sas. is0sctaiasevascss cgucseedaentasiestaddas I. acutifrons. ‘ { I. sordidus. The shell not moulted but. retained.........0i.c..00.s.cees.secsnoccecsaccwonsuce 1 F. spine ; I. sordidus. Antennules not more than eight times as long as broad............sseee0e I. agilis. I. acutifrons. Antennules more than eight times as long as broad..........sceceesseeerees I. spinifer. 4 I. sordidus. Claw of post-abdomen pectinate...............ssccescsesescesscoseecsesenscererace I. acutifrons. Claw of post-abdomen not pectinate gE. p PIC CUTNALG coceels.as soxbsk odossaeaenivacussesencs nara I. gpinifer. ANSELONS SPINE INITODY OFCIAW tcc ccs octece-cvenates ccs setie se sene sce eee eee I. acutifrons. ( I. sordidus. Fine bristles or none in front of claw. 9.; <-< 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 sete (3°). Three species are described, one of which is very abund- ant in Minnesota. * Acroperus leucocephalus Koch. PLATES LXI, Fie. 5; LXII, Fie. 9. Lynceus leucocephalus—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 «arinated. Lower margin of the shell pectinate, terminating in two 15 eee 228 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. teeth. The antenne are long and when reflexed the sete reach nearly to 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 jess 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 C. angustatus; the antennee 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 ©. leucocephalus, to which it has been previously referred. There is always a rudiment of an additional pair of feet. A. cavirostris P. EK. 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 énd of the beak than the eye. (Acroperus transylvanicus Daday.) ‘Carina capitis rotundata; testa corporis dorsali leniter rotundato; postice angulo indistiucto; 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 antenne have usually but seven sete ($24). The species enumerated are so closely related as almost to baffle definition. P ENTOMOSTRACA OF MINNESOTA. 229 KEY TO THE SUB-GENUS CAMPTOCERCUS (VERUS). I. Beak pointed. A. Head depressed. a. Pigment spot larger thantheeye.. . . . . . biserratus, 229 b. Pigment spot smallerthan theeye. . . . . . macrurus, 229 me ead directed forward... . . . + «. .~-. . reetirostris, 230 Meeetemicamineate below... -.. . . . . . . . . « Jatirostris, 230 Ill. Beak cleft below or with a forward projection. A. Antennules shorter than the beak. . . . . . . Jilljeborgii, 230 B. Antennuleslonger than the beak. . . . . . . Yrotundus, 230 Camptocercus biserratus Schoedler. PLate LXU, Fic. 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, Fies. 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 eo Ser AN SF PS a a ny ¥ 7 I, aha ‘ “i ie eA 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. Camptocercus 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. Iam 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 LXIIJ, Figs. 1 and 2. The male has a hook upon the first foot. Not yet recognized in America. Camptocercus latirostris Kurz. PLATE LXII, Fies. 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 ©. 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. * Camptocereus 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 ld SS ae i oe 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 A merica. Shell sub rectangular, high, produced into a ridge above; lower margin convex anteriorly, concave behind; beak rather long; anten- - nules slender; antenne 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 carinate. 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. 232 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. *Alonopsis latissima Kurz. PLATES LXI, Fic. 8; LXIII, Fies. 1 and 9. Body very high, compressed, with a high dorsal keel or ridge; the upper outline strongly and evenly arched, terminating behind in no angle; lower margin almost angled at the anterior third, rounded be- hind, fringed with long bristles anteriorly, with short ones posteriorly. Head very narrow; beak extremely long; fornices small; antennules nearly as long as the beak, straight and narrow; pigment fleck smaller than the eye. The abdomen is long, somewhat narrowed toward the end, where it is deeply cleft; the terminal] claw is furnished with a large and small basal spine, while there is an increasing series of spines extending to the middle. The elongated spine of the third foot is pectinate and reaches nearly to the posterior margin of the shell. The shel! is marked by a few strong strie which are diagonal except anteriorly where area few parallel to the front margin. The male is small and lacks the crest on the back, while the lower margin is straight; the antenne are longer than the beak and differ somewhat from those of the female. The first foot has a claw. The post-abdomen lacks the anal teeth. Kurz gives the size as 0.5 mm. The American form varies between 0.45 mm. and 0.55 mm., and seems to have a higher dorsal keel and longer beak. Kurz speaks of but a single accessory spine on the terminal claws; there is, however, a second very minute spine or cluster of hairs in this as well as the following. Found in the same gathering with the following near Minneapolis (marshy off-set from Bassett’s creek near Oak Lake Addition) :* * Alonopsis latissima var. media Birge. PLATE LXI, Fiea. 9. I give Birge’s description verbatim. ‘‘Rostrum prolonged, and shell sharp, somewhat quadrangular in shape, marked by strie. The dorsal margin is convex, the hinder margin nearly straight. Its lower angle is rounded and without teeth. The lower margin is concave and has long plumose sete. The front margin is strongly c»nvex. The post-abdomen is long and slender, resembling that of Capmtocercus, and is notched at the distal extrem- ity; it has two rows of fine teeth and some fine scales above them. The terminal claws are long, slender, with a basal spine, a spine in Note To ALonopsis Latissima. (See Fig. 1, Plate LXUIL.) Since writing the above the males of our American form have been found; they are shaped as the females, with a high dorsal keel; the post- abdomen is rounded, with transverse series of small bristles; the claw has a minute median spine, and the porus genitalis is anterior and elevated. ENTOMOSTRACA OF MINNESOTA. 233 the middle, and are serrated. The antennules are long and slender, but do not reach to the end of the rostrum. They have each a flagel- lum and sense hairs. The antennz are small and have eight (2{¢ setze and two (42°) spines. The labrum resembles that of A. leuco- cephalus, but is slightly prolonged at the apex. The intestine, cecum and color resemble those of Acroperus. There is a trace of a keel pres- ent on the back.’’ The specimens seen in Minnesota resemble this species very nearly, apparently, but there are some differences. The terminal claw of the post-abdomen has an increasing series of spines to the middle; there seems to be no lateral row of scales beside the anal teeth; the abdo- men is rather broad at the base and narrows toward the end. The shell is not square behind. The lower margin has a few long hairs anteriorly which are followed by a series of teeth, and in the concave part a somewhat longer set to a point just before the lower curved angle. The pigment fleck is nearly or quite as large as the eye. The an- tennule is shorter than the beak (which is almost as in Plewroxus hastatus), and has a flagellum about midway; at its base it is narrowed and inserted on a prominence. The embryo still in the brood-sac has a more elongate form and hexagonal reticulations upon the shell, while the antennules were longer than the very long beak, and the pigment fleck was smaller than the eye. Length of female 0.52 mm. The color is darker, and the striz more numerous, than in A. latissima. From a private letter we learn that this form is now regarded as simply a variety. SERIES B.—This section includes Leydigia, Graptoleberis, Dunhevidia (= Crepidocer- cus), Lynceus, Alona, Alonelia, Pleuroxus, Phrixura, Chydorus, Anchistropus, Monospilus. GENUS LEYDIGIA Kurz. In this genus, both the known species of which are found in America, the posterior part of the shell and body is emphasized at the expense of the anterior. The curved posterior margin is equal to the greatest height of the shell. The head and anterior part of the body are of the form characteristic of Alona; indeed, the whole body is in plan like Alona, but in the back part the organs are all enlarged. The general form of the body and abdomen recalls Jlyocryptus; the post abdomen, in particular, is very like that genus. The last two pairs of feet are much enlarged. The shell is usually irregularly marked with longitudinal strie; the lower margin is covered with long spine-like setze. The post-abdomen is armed with several sets of . ea 7 Ym * : . z % 234 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. long spines and aggregations of bristles and small spines; it is almost round and enormously enlarged. The intestine is coiled and expanded at the end but the anal cecum is rudimentary. The antenne are heavily spined and have eight setze; the labrum is more or less hairy. The male has a strong hook on the first foot, and between the terminal claws of the abdomen is a peculiar intromittent organ. *Leydigia quadrangularis Leydig. PLATES LIX, Fic. 6; LX, Fie. 4. Lynceus quadrangularis—Ley dig, Fric. Alona leydigii—Schoedler, P. E. Mueller. The shell is comparable to that of Alona quadrangularis, but higher behind; the markings are not very distinct; shell transparent. The head is very small; the eye smaller than or of about the size of the pigment fleck. The post-abdomen is very broad, the posterior margin nearly the segment of a circle, armed with numerous very long unequat spines which extend only about half the height, being replaced by short close hairs; the anal opening is very high; the terminal claws . are long, straightish, and have a small thorn near the base. The males are smaller than the females, and the abdomen is less broad; the antennules are longer than the beak and furnished with a flagellum. The sexual period occurs in September or irregularly. This species has only been encountered once, during September, in Poplar river, Cullman county, Alabama. *Leydigia acanthocercoides Fischer. Lynceus acanthocercoides—Fischer, Leydig. Eurycercus acanthocercoides—Schoedler. Alona acanthocercoides—P. E. Mueller. Leydigia quadrangularis—Herrick. This species, reported in a previous paper, is, aS was said, nearest like L. acanthocercoides; and I am now able to verify the very incon- spicuous differences upon which the two are separated. Our specimens of the L. quadrangularis have the pigment fleck fully as large as the eye, Kurz to the contrary notwithstanding, and the spine of the claw of the post-abdomen is present, while in the present species the pig- ment fleck is much larger and furnished with lenses; the spine of the claw is wanting; the labrum is densely hairy; the abdomen is narrower, and the shell higher. The shell is very obviously striped in the pos- erior portion. The anus is higher thanin the previous species. In ther respects the two seem alike. ENTOMOSTRACA OF MINNESOTA. 235 [Alona balatonica Daday. } This is apparently simply LZ. acanthocercoides with unusually sharply marked shell. The figures are very poor. Leydigia australis Sars. PLATE LXVI, Fig. 7. Very similar to L. acanthocercoides. Head comparatively erect, rostral projection not much curved. Body quadrangular, expanded behind and obliquely truncate. Macula nigra at least three times as large as the eye. Antennules reaching nearly to the end of the beak. Abdomen very large, lamellar. Spines about 20, increasing distad. Length 0.84 mm. The points most relied on to distinguish the species are the large size of the macula and the absence of teeth from the claws. A very full description with numerous figures is given by Sars. GENUS GRAPTOLEBERIS Sars. A genus having affinities with Alonella. The shell is entirely re- ticulated, and there is a sort of crest along the back; while, on the other hand, the head is flattened and rounded in front. There can hardly be said to be a beak. Seen from above, the animal resembles some species of Alonella, but the head is larger proportionally and more horizontal. The lower posterior angle is spined. The an- tenn have seven sete and are very long, in this respect resembling Camptocercus. The dorsal contour is not greatly arched. The post- abdomen has short claws and anal bristles, but no teeth. * Graptoleberis testudinaria Fischer. PLATE LXV, Fias. 8, 11, 12. Lynceus testudinarius—Leydig, Lilljeborg. Lynceus reticulatus—Fric. Alona testudinaria—Schoedler. Graptoleberis inermis—Birge. Form trapezoidal; lower margin straight, armed behind with two teeth, thickly beset with long hairs in front; the dorsal margin is not greatly elevated, rounded at the posterior angle, forming a slight “hump” where it unites with the head shield. The head and shell are reticulated with hexagonal or quadrangular markings. The shell gapes below and rises to a sharp ridgeabove. The antenne have long rami, the antennules being hardly longer than the fornices. The eye is large; the pigment fleck is small. The post-abdomen is narrowed 236 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. toward the end, rounded in front; the terminal claws are small and have two basal teeth. The dorsal margin of the post-abdomen is coy- ered with tufts of hairs. The winter eggs have noephippium. Length 0.55 mm. to 0.7 mm. The male is smaller and has a lower dorsal keel; the post-abdomen is excavated behind. The only differences between the Minnesota specimens and the typi- cal European form seemed to be the absence of the very minute spines on the front of the terminal claws. The eye and pigment fleck are of about the proportions figured by Kurz. Birge’s figure of the post- abdomen does not agree with his description fully. Our Minnesota specimens have an obvious but not high keel. ; * Graptoleberis reticulata Baird. Alona reticulata—Baird, P. E. Mueller. Lynceus reticulatus—Lilljeborg, Leydig. Alona esucirostris—Schoedler. Shell almost rectangular, reticulate, ventral margin straight, ciliate anteriorly, with two teeth behind. Pigment fleck smaller than the eye. Post-abdomen short, narrowed towards the end, dorsally coy- ered with clusters of spines; caudal claws with a minute tooth at the base. Length 0.4 mm. to 0.5 mm. The pigment fleck is nearer the end of the beak than the eye, and is smaller than in the previous species, but, on the whole, there is, perhaps, too great similarity. Professor Birge writes that he unites the two species. GENUS DUNHEVEDIA King. Crepidocercus — Birge. The characters of this group place it rather near Alonella or between that and Pleurovus. Form sub-quadrate with rounded angles; dorsal line uniformly arched, terminating in a sharp angle behind; lower margin convex, armed behind with a single spine as in Plewroxus unidens, and along the entire length with loose sete. Beak of moder- ate length, acute. Post-abdomen deeply incised in the anal region; lower posterior margin straight, rounded at the apex; ventral margin straight or concave; claws with a single basal spine and a few teeth. The post-abdomen is shoe shaped and armed with transverse rows of sete. The antenne are large, having eight sete and the usual spines. Shell smooth or reticulate. Founded by King to include two species from Australia, D. crassa and D. sodagra. ENTOMOSTRACA OF MINNESOTA. 237 *Dunhevedia setiger Birge. PLATE LXIV, Fie. 3. Length 0.4 mm. to 0.5 mm. Minnesota specimens measured 0.5 mm. This species is but rarely encountered, and is so peculiar as to be easily recognized when seen. Alona intermedia has a post-abdomen with clusters of bristles, but in Dunhevidia the post-abdomen is more as in species of Graptoleberis than any other genus. The markings upon the shell are very indistinct. Birge says that the male is simi- lar in form to the female. The first foot has a stout hook. Theclaws are smooth in both sexes. This species has been found by Daday in Hungary. GENUS LYNCEUS O. F. Muller. The perplexing inter-relations between the three genera Alona, Alonella and Pleuroxus give rise to the utmost confusion. No two authors are agreed as to their respective limits, and the points given by Kurz, who has carefully gone over the ground, are obviously in- sufficient. Although there may be practical benefits to be derived from the continuance of the nomenclature in use for groups which in the general view can be distinguished, the value from a theoretical standpoint is reduced to a minimum. The genus Camptocercus (including here Acroperus, which differs solely in the form of the abdomen, as a sub-genus) passes through Alonopsis into the group represented by Alona. Leydigia, although very near such forms as Alona quadrangularis, may be conveniently distinguished as a transition to species like L/yocryptus. Phrizura, Graptoleberis and Dunhevidia, each containing few species which can be readily recognized, fill a place in the system; but it is practically impossible to distinguish Alona from Plewroxus without in- stituting the very indefinite genus Alonella to contain a variety of small intermediate forms. Percantha, Rhypophilus, Harporhynchus and Pleuroxus seem to be pretty generally regarded as constituting a single group which may be recognized by the long rostrum, high shell and greater development of the antenna bristles. Alona, on the other hand, with its broader fornices, shorter beak, fairly developed an- tenn, and more rectangular shell, is, perhaps, the pivotal point of the group. According to this view, then, the old name Lynceus is re- vived for the aggregate; and the other names are retained, in part, as titles of largely conventional groups or sub genera, thus: 238 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. GENUS LYNCEUS. Sus-Genus ALONA—Section A, Alona vera. Section B, Alonelia. Sus GENUS PLEUROXUS—Section A, Plewroxus verus. Section B, Leptorhynchus.* Characters of Percantha and Rhypophilus are combined in the species P. procurvus, Birge, so that one must be dropped or new diagnoses. formulated. JI am not sure that the same species is not at first Pleu- roxus verus* and only later assumes the form known as Rhypophilus. So with Percantha the amount of serrature of the posterior margin is. in part a question of age. SUB-GENUS ALONA. This group contains two sections which resemble each other in form and, in general, in detail; but it is exceedingly difficult to formulate a diagnosis that shall strictly limit it. The form is generally sub- quadrangular with rounded corners; the terminal claw is armed with but a single spine at the base; the beak is rather short; and the pre- vailing marking consists of longitudinal lines. Section A, Alona (vera) Baird. This genus contains a large number of minute animals which are widely distributed. The authors who have done the most to elucidate this genus are Schoedler, P. E. Mueller and Kurz. Birge has contributed most largely, thus far, to the knowledge of American species, which are, for the most part, identical or very close to the European. No other genus is so difficult among the Lynceide, for the most minute differ- ences are relied upon to distinguish species. The species of this genus are not greatly altered by the production of the winter eggs. The maies are frequently but little smaller than the opposite sex, and are recognized by the altered form of the post-abdomen and the presence of a hook on the first foot. The form is more perfectly rectangular than in the next section; the shell is only exceptionally reticulated and very rarely tuberculate, occasionally smooth. The lower angle of the shell is not armed with spines, but is generally rounded. There is only one basal spine upon the claw of the post-abdomen, which usually bears a row of scales beside the anal spines. The antenne have eight sete. The claw of the male post-abdomen is removed from the lower angle. Many species are known, all of which that seemed recognizably de- fined have been included in the following key, which is believed to 1 Instead of Harporhynchus, a name preoccupied in zoology. 2 Embryos of P. procurvus have the part which is to be curved forward attenuated before leaving the brood cavity, however. 4 ! ENTOMOSTRACA OF MINNESOTA. 239 more nearly represent our present knowledge of the genus than that of the previous edition. Unfortunately the key must be based on the statements of other authors, and in this genus it is rare to find com- plete agreement between the published descriptions. The best thing a student can do is to disregard much of the synonomy and make an exhaustive study of a species from a large number of individuals in one locality and then cautiously extend the range of work to include _ adjacent stations. KEY TO THE GENUS ALONA I. Macula cerebri much larger than the eye. . Sanguinea, 239; moniezi, 240 il. Macula cerebri about as largeas the eye. quadrangularis, 240; (affinis, 240 oblonga, 240;) lepida, 242. . . . . (Seealso intermedia, 244) III. Macula cerebri smaller than the eye. A. Post-abdomen narrowed toward the end, at least not broadly rounded. a. A single series of anal spines. * Strie oblique to the axisofthe shell. . . . . lacustris, 242 ** Stricz parallel to the axis of the shell. 7 Abdomen very long, with long anal spines, (One form of) tenuicaudis, 242 jt Abdomen not very long. . . . . guttata, 243 b. A lateral as well as an anal series of jesk-abdiininal spines, sete or scales. * Post-abdomen long and slender. (Usual form of ) tenuicaudis, 242 ** Post-abdomen of ordinary form. + Anal spines two. Row of sete in addition. . dentata, 244 tt Anal spines represented by transverse clusters ef bristles. intermedia, 244 tit Anal spines large, nearly equal... . . . . pulehra, 245 tttt Lower anal spines larger... . . . . . . porrecta, 246 B. Post-abdomen broadly rounded below. a. Analspinesinasingleseries. . . . . . . . Stagnalis, 246 b. A double series of anal spines. * Striz of shell close, fine and oblique. . . . . elegans, 247 ** Striz of shell distant. 7 Strie oblique. . . . . .angulata, 247 t{Strie parallel to the ianeitsauiaat ee axis of the Shetl, coronata, 247 (Not noticed inthe key. . . . . . . . costata, 245; barroisi, 248) * Alona sanguinea P. E. Mueller. PLATE LXII, Fie. 20. Body nearly rectangular; ventral margin nearly straight, with short sete; posterior angle rounded, unarmed. Beak short; pigment fleck much larger than the eye. Post-abdomen large, the end truncate, broadened; posterior margin rounded, with a series of spines and a 240 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. lateral row of scales; terminal claw with asmall spine. The shell is ornamented with fine, close, longitudinal striations. Length 0.9 mm. Alona elegans is very near to this and should have followed. In August, 1878, I took an Alona marked as in 4A. sanguinea and agreeing with Mueller’s description in all points which can be verified in the draw- ing. The small size of the eye is remarkable for so large an animal. I have never again seen this species; it seems to be very rare here and in Europe. Alona moniezi Richard. Richard ’88. ‘*Testa antice quam postice Jatior, striis multis, interdum areis ornata, supine sat arcuata, postice fere truncata, angulo inferiore rotundato, inferne subrecta, ciliis longis, hic obsita. Antenne 1mi paris apicem rostri fere attingentes. Articulus ultimus utriusque rami antennarum 2 di paris, setis 5 longis et aculeo forti preditus. Rami exterioris articulus penultimus longa seta instructus. Macula nigra oculo major, inter hune et apicem rostri in medio sita. Post-abdomen breve latitudine fere zequali, ad angulum posteriorem et inferiorem rotundatum, seriebus (8-9) aculeorum (4-5 quorum exterior multo major) fusiformium, preterea aculeis minutis equalibus fasciculatim usque ad processum obtusum positis, armatum. Adest denique series lateralis squamarum spinis gracilibus ac longis compositarum. Ungues terminales sat longi, usque ad apicem ciliis minutissimis obsiti, dente basli gracile, et sat magna. Setze abdominales longs. Mas femina majore paulo dicrepans. Postabdomen brevius, latum, spinis unguibusque terminalibus multo brevioribus quam infemina, ommatum. Pedes 1 mi paris in hamulo valido curvato ad basin crasso, apicem versus acuto ex- euntes. Longit. fem., 0.5-0.55 mm.; mas., 0.45-05 mm.”’ Found near Vichy. * Alona quadrangularis Miiller. PLATE LX, E1Gs. Jy 2: Alona oblonga—P. E. Mueller. Alona affinis—Ley dig. Alona suleata—Schoedler, Hudendorff. The group of forms included under the above names is in inex- tricable confusion. Hellich evidently describes the same species as quadrangularis and affinis. A ffinis falls little short of one millimeter in length while quadrangularis is less than 0.75 mm. A. oblonga is said by Kurz to measure 0.8 to 0.9mm. He, however, did not know A. affinis. Hellich says that there is a secondary marking of the shell in A. affnis. The claws are smooth in quadrangularis and ciliate or toothed in affinis. Statements of various authors differ respecting the relative size of eye and pigment fleck. The American form, which most closely approaches affinis, has the claws denticulate and the pigment fleck smaller than theeye. In the figure (Plate LXIV, Fig. 14) the head is somewhat protruded by ENTOMOSTRACA OF MINNESOTA. 241 pressure, but there is nevertheless greater proportional length than in ordinary specimens of A. quadrangularis, and we may have to do with a new species. Accordingly we quote our original description. “*Rorm sub-quadrangular; height about once and one-half in length; the dorsal outline forming a regular and low curve from end of head to upper posterior margin; lower outline very slightly sinuate, ante- rior one not at all; posterior angles rounded; head nearly horizontal; eye of moderate size; pigment fleck considerably smaller; antennules rather large, with unequal sensory hairs at the end, one spine just above the end in front and a bunch of minute hairs near the base behind; antennz comparatively large, basal joint spiny, outer ramus with three set, two of which have thorns at their middle, also a termi- nal spine; inner branch with two of the terminal set thorned and the upper lateral sete reduced. The post-abdomen is very broad and short, expanded below and rounded at the end; the terminal claws are straightish, denticulate, and the spine at the base is also dentate; there is a series of heavy spines on the upper margin of the post-ab- domen, accompanied by a series of scales on the side. The shell is unornamented and fringed below with short bristles. Length 0.9mm., or more. This fine species is recognized by its smooth shell, the hori- zontal position of the head, and the form of the post-abdomen; it be- longs among the largest of the genus. Lakes near Minneapolis not rare. ‘“*Birge quotes A. spinifera from Wisconsin. In all probability that species is the younger stage of the above.”’ The American form, which we identified with Alona oblonga, was said to differ from 4. guadrangularis in the following points: “The greatest height of the shell is anterior to the middle; the lines are less evident, and all confined to the lower part of the shell, while the centre of the valves is marked with very minute strie; the pigment fleck equals the eye, and the post-abdomen is of about the same width throughout and hardly as round below. This and the preceding species have a well-marked keel on the process of the labrum, The size is greater, this being one of the largest and most abundant, as well as one of the most striking species. It, perhaps, should rank as a well-marked and permanent variety of the above. Length 0.9 to 1.0mm. The abdomen of the male is narrowed at the end and lacks the teeth. Lakes about Minneapolis. “A small form of 4. quadrangularis in Lake Calhoun had the eye and pigment fleck equal and the terminal claw smooth. )’’ We are satisfied that a wide range of variation must be allowed for. The presence or absence of markings is unreliable. 242 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. * Alona lepida Birge. General shape of the genus. Head depressed, rostrum sub-acute, nearly reaching the level of the ventral margin of the shell. Valves quadrangular, dorsal margin arched, caudo-dorsal angle obtuse, well marked. Caudal margin oblique, bearing a row of spinules. Caudo- ventral angle rounded, very slightly emarginate. Ventral margin with plumose sete. Valves marked by closely-set, conspicuous, longitudinal strix, alternately stronger and weaker, occasionally anas- tomosing, parallel to the dorsal and ventral margins and converging to a reticulated area at the cephalo-ventral portion of the valves. The antennules extend nearly to the end of the beak, are small, spin- dle-shaped. Antennary sets 32°. The terminal sete are of unequal length. All are plumose and without spines. The eighth seta is of moderate length, bi-articulate and plumose. Spines of antennze +{4. Hye moderate. Macula about as large as eye, angular, and somewhat nearer to eye than to apex of rostrum. Post-abdomen enlarged pos- teriorly, lower angle rounded, bearing 15 to 17 serrate post-anal den- ticles and about the same number of squame. Terminal claws smooth. Basal spine rather large. Abdominal sete of ordinary length. Length0.8 mm.; male 0.6mm. Obviously this species is near to A. elegans. Alona lacustris Daday. Daday ’88. ‘‘Rostro brevi; macula cerebrali oculo minore; labro processu mediali glabro; testa corporis striis longitudinalis dense vestita, linea dorsali parum arcuata, margine ventrali subrecto, setas postice breviores gerenti, postice angulum obtusum inermem formanti; cauda brevi, apicem versus rotundatum attenuata serie fere marginali aculeorum sensim minorum armata, unguibus caudalibus unidentatis. Longit. fem., -0.4-0.5 mm.; altit. 0.35-0.4 mm.’’ It is questionable whether this form is sufficiently differentiated from A. parvula; it is also very like A. gultata—A. intermedia. Alona tenuicaudis Sars. PLATE LXII, Fie. 11. Alono camptocercoides—Schoedler. Form nearly rectangular; ventral margin rounded, with long sete, ‘posterior angle rounded. Beak short, pigment fleck smaller than the eye. Post-abdomen with sides parallel, long, incised below; lower angle armed with about six strong teeth, remainder of the series small; a lateral line of scales present; claws with a strong basal spine. The shell is striate with longitudinal lines. Length 0.5 mm. One of the most easily recognized species; not identified in America. ENTOMOSTRACA OF MINNESOTA. 243 It would appear that the lateral line of scales upon the post-abdo- men may be absent. There is often, if not always, a cluster of fine spinules above the spine on the otherwise smooth claw of the post- abdomen. Alona guttata Sars. Norman and Brady ’67 (Lynceus guttatus); Kurz ’74 (parvula and tuberculata); Hellich ’77 (anglica, and guttata); Matile ’90. A small species of sub-quadrangular form. The beak is very short; the eye small, but larger than the minute pigment fleck. The shell is short, with a rounded posterior angle and marked by hexag- onal or rectangular meshes running about parallel with the lower margin. Tne post-abdomen is of moderate size, rounded at the apex, with a series of stout teeth behind; the terminal claw has a minute basal spine. P. E. Mueller, in Danmark’s Cladocera, confused this with A. intermedia, which he described under this. The post-abdo- men in that species is larger, less rounded behind, and armed with clusters of spines instead of teeth. The length is about 0.3 mm. in both. In males the hook is small and the anal spines are absent. *** Alona parvula Kurz is said to have the body sub quadrangular, arched above; ventral margin straight, rounded behind. Shell marked by longitudinal, feeble and irregular lines. The post-abdomen is nar- rower toward the end, with eight or more teeth; the row of scales is absent; at the end it is sharply truncate and incised; the claws have short basal spines. Hardly to be distinguished from the next. ** Alona parvula var. tuberculata Kurz (Alona tuberculata Kurz) de- scribed by Kurz in 1874, and more at length by Lutz under a different name (Alona verrucosa) in 1878, appears to be simply a tuberculate variety of the above. Observations upon the American representa- tives of the two forms indicate a close relationship between them. The shell is covered with rows of tubercles (or depressions?) which vary in bumber greatly. “I do not know how to distinguish *Alona glacialis Birge (Plate LXIUI, Figs. 2, 3 and 8) certainly from A. parvula. It, however, seems to have the lower angle of the post-abdomen less squarely truncate and the incision less obvious. Birge says that the abdomen is rounded. I have found specimens which apparently belong here, with the post- abdomen rather sharply angled and deeply incised; there were about fourteen teeth with a row of hairs in front. The form is hardly to be distinguished from another variety which has a shorter post-abdomen, rounded below, and with only about seven or eight teeth and with a Smooth shell. This form passes directly into a tuberculate variety, ___ haying the post-abdomen similar but the shell covered with numerous 16 a 244 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. rows of tubercles. Sometimes a transition from a lined shell to a tubereulate shell is seen (as in Plate LXIIM, Fig. 14). Alona tubereulata Kurz is said to have a truncate and incised post-abdomen with no lateral row of hairs. Birge thinks these identical; if so, our form re- ferred to A. glacialis is identical with A. parvula. There is also a form found with the above in which no markings are visible and the shell is considerably arched; these were, however, nearly all ephippia females or approaching that period. *** Alona glacialis (2) var. tuberculata Herrick (Plate LXIII, Figs. 4-7 and 14) will, then, be our tuberculated a/ona with a lateral row of scales and a series of fine spines along the anus. Alona glacialis (2) var. levis Herrick is the smooth form with higher dorsal margin. ‘‘The antennz of the two last have spines at the end of the rami of the antenne, a circlet of spines on the outside of the second joint of the setose ramus, and a spine on the basal joint of the other ramus; two of the set at the end of the setose ramus have spines at the angles. The males found among the above small forms have the same characters as var. levis and the abdomen is rounded at the end; the claw is situated in the middle of the lower margin, in front being the opening of the porus genitalis and behind a cluster of hairs; the spines are absent, but there is a lateral row of long bristles. A strong hook is found on the first foot. Length 0.3 mm.” To the above, which expressed my opinion in 1884, I can only add that I am more than ever convinced that all should be united (probably with A. guttata). Alona dentata P. E. Mueller. PLATE LXII, Fies. 12, 13. Form sub-rectangular, somewhat arched above, obscurely longi- tudinally striated; lower angle obtuse, margined below with short setze. Post-abdomen small, slender, armed with a lateral line of scales and two strong teeth at the lower angle; claw with a minute basal spine. The form of the post-abdomen is identical with Harporhynchus falcatus Sars, which this species also resembles in having the pigment fleck larger than the eye, and in general form and the character of the striation. The beak, however, is very short. In size P. E. Mueller ~ says it is among the smallest of the genus. Alona intermedia Sars. j PuLaTE LXII, Fic. 15. Alona guttata—P. E. Mueller. Form sub-rectangular, rounded below; beak short; shell marked by longitudinal lines, which may be broken into indistinct rectangular eee ae he ee oe 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 pulchra Hellich. Sars ’61 (rectangula and lineata); Hellich ’74 and ’77 (lineata); Matile ’90. We are influenced by Matile in not recognizing A. Jineata 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 sete 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. Antennz with only seven sets. Labrum small. The shell is strongly and coarsely striped parallel to the shell margins. Lower margin straight or concave, armed with rigid setz. 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 lowershell 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 A. 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 striz; 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. tenvicaudis 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. 2Q47T diocres gerenti, postice angulum obtusum, inermem formante; cauda brevi, apicem versus rotundatum dilatata, margine dorsali utrinque serie muarginali 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, Fie. 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 obyious 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. Fornices 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 4. 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 tn ee ty” we eT: AS dla 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 Veil, Vappendice 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 y a 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. aculeaius is Alonella exigua. A. angusticaudata Hudendorff is Alonopsis latissima. A. balatonica Daday is A. Leydigia. A. camptocercoides Schoedler is A. tenuwicaudis. A, esocirostris Schoedler is Graptoleberis. A. excisa is alonella. A. elongatus Sars is Alonopsis. A. falcata Sars is Leptorhynchus. A. grisea is Alonella. A. glacialis Birge is a variety of A. guttata. A. inornata Hudendorff is A. coronata. A, insculpta is Alonella excisa. A, leydigia is Leydigia. A. lineata Fischer is unrecognizable. A, latissima is Alonopsis. A. minuta Poggenpol is insufficiently described. A. modesta Herrick is A. costata. A. nanus is Alonella pygmea. A. ovata Baird is uncertain. Sy ay a *. L a , r 7 ay 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. . sulcata 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. . testudinaria is Graptoleberis. . verrucosa Lutz is A. guttata. A A A A A A A A. A A A A A A 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 lower 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 setz on the antenne, or the eighth is a minute hair; on the ramus having the lateral set one of the terminal sete is frequently reduced. In many cases the whole shell is marked by minute striz in addition to the proper markings, but this is also found in some species of the true Pleuwrovus. 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 (4. exigua), and Schoedler figures eight sete on the an- tenna of A. ercisa. American specimens of A. ercisa 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 Iynceids 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. . Rostrum long, bent backwards. ou 35 Wags ne ae tae. Swe hr eee 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. | Head'depressed.*s 2 yer s ie ee es pe ee +t Head horizontal. . . : . » ~ grisea, 252 b. Shell marked by lines running Siegen uO WEE and backwards “se Riek a pygmeea, 253 B. Lower posterior angle Siinoth, shell lenertadlinally striate. striata, 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 4A. 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 strie. 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 pulchella Herrick. PLATE XIII, Fias. 1-3. A minute form very recently obtained is described under the above name. Although closely allied to A. exigua, this species is more like Fraptoleberis than any other member of the genus. It is the smallest of the Lynceids, excepting A. pygymea. The shell is high and rather: strongly arched; the posterior margin is short and armed with four teeth below, which point in different directions as in Graptoleberis. The head is short and the antennules long. The pigment fleck is of 1 ee ae ee eS ee ee ee eee ; : Br: : 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, Fies. 6-7; LXIII, Fies. 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 0.35 mm. Birge gives 0.27 mm. for the length of Plewroxus insculptus, and our specimens varied iu 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 252 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. Schoedler. I must here express my suspicion that the Pleuroxus 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 antenne have eight set, 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 striz, 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 A. exigua, save that the former speaks of spines, and the latter of thorns, along the post abdomen. Alonelia 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 0.33 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 as ke 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—F ric. Alonella pygmxa—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 0.28mm. 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. evigua 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 setsze 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 strie 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. . . . . . adunectus, 255 C. Shell striped. a. Shell very long and low. * With one tooth below. . . . « Sraciiszi2s7 ** Without a tooth; female witha HG s upon fee: first foot. hamatus, 257 b. Shell high. * The whole posterior margin of the shell spined. . . . truncata, 258 ** The lower angle of the shell spined. 7 Antenne with eight sets; the anterior margin of the valves toothed. . 2. 0.08 ea os a dd enticulatissess +{ Antenne with seven sete. . . . . . . =. +. +» WDalirdil, 256 Beak procurved (Rbypophilus). A. Shell reticulate (either strongly or ate 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. . . . . . unecinatus, 259 (Not noticed inthekey. . .. .... =. =. . . trigonellus, 255) Pleuroxus hastatus Sars. PLATE LXII, Fic. 16. Pleuroxus 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, PY ‘ae 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 striz 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. E. Mueller’s Plate IV, Fig. 18, with the outline given by Birge at Plate II, Fig. 11. The color in both is deep» 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. Miller. Lynceus trigonellus—O. F. Miiller, Lievin, Lilljeborg, Leydig, Fric. 2 Pleuroxus ornatus—Schoedler. Dorsal line strongly arched; the beak rather long, straightish, pigment fleck smaller than the eye. 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. GEOL, AND NAT. HIST. SURVEY OF MINNESOTA. bo or for) Pleuroxus bairdii Schoedler. Pleuroxus trigonellus—Baird. This form, so far as can be gathered from Baird’s brief description and figures, differs from the others in having the shell marked by ~ . straight parallel lines running diagonally back and upwards, and in lacking one of the terminal bristles on the 5-setose ramus of the an- tennz. The first is a possible but unusual structure, while the second might result from an overlooking of the very small seta which fills this place inthe other forms. Baird himself did not distinguish it from P. trigonellus. *Pleuroxus denticulatus Birge. PLATES XLV, Fic. 8; LXIII, Fries. 10a, 12, 13. Resembling very closely P. adunctus, which, however, has a broader post-abdomen than the ordinary P. denticulatus. The posterior angle of the shell is armed with from one to four (generally three) teeth. The beak is very long. The character most emphasized by Birge is a series of teeth along the anterior margin of the valves. The same thing is found in P. pro- curvus, aS I have repeatedly satisfied myself. In certain positions these teeth do not show, or the smaller teeth on the lower margin only appear. P. adunctus, as figured by Schoedler, has similar teeth on the lower margin, and very likely has them anteriorly. The edges of the valves are heavily fringed with pectinate sete. The male has ashorter beak and the post-abdomen simply rounded without the peculiar modifications seen in P. adunctus. There seems to be two varieties in Minnesota, both of which have the characteristic irregular striations, which radiate from an irregu- larly marked or unmarked area in the centre of the shell toward the edges; both have the toothed posterior angle and the serrated posterior angle and the serrated anterior margin. But the common form is much longer, with the dorsal margin less convex and the beak shorter. The robust form has a larger pigment fleck, while the post-abdomen is shorter and more robust, resembling more nearly Schoedler’s figures of the abdomen of P. adunctus. There is another variation or abnor- mality, in which the lower margin is quite concave. The resemblance to P. procurvus is remarkable in some phases. ‘ I have collected this species in Blount springs, Ala., in the St. Croix river, and at various intermediate points, as well as very often in Minnesota. ENTOMOSTRACA OF MINNESOTA. 257 *Pleuroxus hamatus Birge. PLATE LX, Fie. 1. This species is smaller than those of the preceding group and forms a transition to the two next, to be described, in the greater elongation of the shell, which is, however, higher and more strongly arched. The head and beak are much as in P. denticulatus. The lower margin is concave posterior to the middle and slightly convex at the posterior angle, which is unarmed. The lower margin is hairy. The markings are as in P. denticulatus, but, in addition, there is a set of horizontal strie all over the shell. The post-abdomen is widest in the middle and almost exactly as in P. denticulatus. The first foot bears a claw such as ordinarily distinguishes the males. The only specimens which I have seen were from the Tennessee river, near Waterloo, and near Decatur, in Alabama. My notes con- tain no reference to the minute striations, which could perhaps be _ hardly seen with the instrument employed. The process of the labrum is long and rather acute, the beak moderate, and the pigment fleck very large. The markings on the anterior of the valves are irregular and are inter-connected by cross lines or anastomoses. Ova two. (The genus Anchistropus has a hook upon the first foot, but is like Chydorus. ) *Pleuroxus gracilis Hudendorff. PLATE LXIV, Fias. 15, lida. Pleuroxus unidens—Birge. An extreme among these elongated species, the length of body fall- ing little short of double the height. The dorsal line is very flat and slightly but evenly arched; the lower margin is evenly convex or nearly straight, covered by long pectinate bristles. The head is short, and the beak is long and sharp; the antennules are of moderate size, with a lateral seta one-fourth from the end; pigment fleck less than the eye; antenne rather long, with strong thorns on the termina] joints. The post-abdomen is long, as in P. hastatus, sides nearly par- allel; anal teeth sharp, small and numerous; claws pectinate, with two strong basal spines. The shell is strongly striate with longitudinal striz, which are parallel with the different margins. Birge says that there is a reticulated area. The lower angle is rounded, and anterior to it is a small tooth directed backward. This species is distributed throughout the Mississippi valley. I have notes of it from Swan lake, near Decatur, Ala. It is often rather abundant about Minneapolis, but it is thought by Birge to be absent from the Eastern states. Almost all the specimens I have seen are very dark, often brown, so as to ap- pear to the eye like dark specks as they swim about. The length 258 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. varies from 0.55 mm. to 0.85 mm. About 0.60 mm. is a common size, according to my observation. Birge mentions a rudimentary sixth foot in this species. This organ is found in Hurycercus and other Lyneceids, according to Schoedler. Pleuroxus truncata O. F. Miiller. Lynceus truncatus—Muller, Koch, Zaddach, Lievin, Fischer, Lilljeborg, Leydig, Fric. Percantha truncata—Baird, Schoedler, Kurz. Pleuroxus truncatus—P. E. Mueller. Percantha brevirostris—Schoedler. This species is widely distributed in Europe, but is replaced in America by the following. The shell is high, the dorsal contour arched; beak rather long and straight; lower margin slightly convex, setose; posterior margin straight, armed with very strong teeth en- tirely across it; the anterior margin also is dentate, as in the next. ‘The valves are covered with strong striz, springing from the anterio- central part and radiating toward the free margins. The post-abdomen is of moderate size and in form much as in the next. The ephippium causes a considerable change in form and coloration. Inthe male the beak is shorter, and the abdomen has finer teeth. The first foot has an extraordinarily large hook. The length is about 0.5 mm. to 0.6 mm. Percantha brevirostris Schoedler differs in the length of the beak only. *Pleuroxus procurvus Birge. PLATE LXI, Fies. 3, 4. In size and general appearance this most interesting species is similar to the above, and, especially, to P. denticulatus. The general form and even the details of structure agree almost to identity with the latter. The structure of the posterior margin is like Percantha, while the rostrum is bent abruptly upwards as in Rhypophilus. In small individuals the length is greater proportionaliy. The lower margin is slightly convex or nearly straight, and fringed by bristles whieh are strongly pectinate; the anterior and lower margins are toothed as in Percantha. The shell gland is more as in the Daphnide than most Lynceids. The number of posterior teeth is variable. The ephippium is as in P. denticulatus. Length 0.40 mm. to 0.50 mm. Not rare, but less common than P. denticulatus. ‘The male post-abdo- men is like that of P. denticulatus; the rostrum is as in the female. Of the species following it may suffice to say that they are corpu- lent, filth-loving representatives of P. trigonellus, P. adunctus and P, bairdii, respectively, which have turned up their noses at a superficial existence and buried themselves in the mire and debris at the bottom of the pools. It might be fanciful to assume that the curved snout is used for ‘‘rooting,’’? but the fact that these ‘‘Schmutzpeterchen”’ Lynceids would find a long straight beak in the way is suggestive. ENTOMOSTRACA OF MINNESOTA. 259 Pleuroxus personatus Leydig. Leydig ’60 (Lynceus personatus); Schoedler ’62, ’63 (Rhypophilus personatus and glaber); Norman and Brady ’67 (Lynceus uncinatus); Miiller ’68; Fric ’72 (Lynceus personatus); Hellich ’77 (personatus and glaber); Herrick ’84; Daday 788; Matile ’90; Kurz ’74 (glaber). Shell high, oval, smaller caudad. Head small, depressed, with narrow, long, procurved beak. Macula quadrangular, half the size of the eye, to which it is nearer by half than to the end of the beak. The shell is either hexagonally reticulate or smooth. The lower margin is flexed cephalad of the middle and bears long cilia. The ventro-caudal angle bears two curved spines. The post-abdomen is rather broad, narrowed toward the end. Anal teeth 10-11, very large. Claw serrate, and with two basal spines. There are seven sete and a spine upon the antennz. The antennules are fusiform. Length 0.65 to 0.67 mm. There seems to be no reason to doubt that P. glaber is only a condi- tion of P. personatus not even worthy of a varietal name. Pleuroxus (FLhypophilus) unecinatus Baird. The shell is ridged with lines running upward and backward, as in P. bairdii; the lower angle of the shell has three teeth, and the beak is more horizontal than in the above. In size and characters this is almost identical with P. bairdii, with which it occurs in Eng- land. _ This completes the list of swine-like members of the genus; these well deserve to be studied from a morphological standpoint. The following names may be mentioned, though the list of syno- nyms cannot claim to be exhaustive. Pleuroxus nasutus Gay is a poorly described form from Chili, re- sembling, according to Schoedler, P. ornatus = trigonellus. A species of Percantha (Lynceus armatus Gay) is found in Chili. P. exiguus Willj. is Alonella. P. griseus is possibly Alonella pygmea but is said to have two teeth on the ventro-caudal angle of the shell which is faintly reticulated as well as striate. . striatus Hellich is P. gracilis Hudendorff. . striatus Schoedler is Alonella. . balatonicus Daday is insufficiently described. . excisus Fischer is Alonella. . nanus Baird is Alonella pygmea. . levis Sars is P. hastatus. . ornatus Schoedler is the young of P. trigonellus. . trigonellus Mueller is P. bairdii Schoedler. 17 a Rs bg oo by be 260 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. P. glaber Schoedler is P. personatus. P. brevirostris Schoedler is P. truncatus. P. aculeatus Fischer is Alonella exigua. P. convexus Poggenpol is doubtful. SecTION B. Leptorhynchus Herrick.1— The species for which Sars formed the genus Harporhynchus is of Alona-like habit, but has a beak which exceeds that of any known Pleuroxus in length, being sim- ulated in this respect by the American P. acutirostris, which is, how- ever, in other respects more nearly allied to Pleuroxus. Leptorbynchus faleatus Sars. Harporhynchus falcatus —Sars. Alona falcata—Sars, P. E. Mueller. Body oblong, arched above; ventral margin nearly straight, setose, with a spine at the posterior angle; beak strongly curved, folded laterally; pigment spot larger than the eye. The post-abdomen is wide, sides nearly parallel, armed with a few strong teeth below and a lateral line of spines; caudal claw with a single small basal spine. GENUS CHYDORUS Leach. This genus, if it be really of generic value, contains minute rotund animals which appear in the water like animate pin-heads of small size. Their motion isa rolling, wavering hobble; and they live by preference upon vegetation, or in slime at the bottom of pools. Occa- sionally they may be seen in sunshiny weather, disporting themselves near the surface in immense numbers. Thereare two common species, and six more which are more rare or in part not valid. The sexual period occurs at two different periods (i. e., May-June and December), but probably is not confined to any periods. The males, which only rarely are found even in these periods, have the abdomen narrowed or excavated to accommodate it to the peculiar alteration of the brood-cavity which takes place in the sexually ma- ture female. The connection takes place by the insertion of the abdo- men within this chamber, which is facilitated by the reduced size of the abdomen. The modification of the shell of the brood-cavity above referred to consists in the thickening of the wall posteriorly, which may or may not result in the deforming of the shell as shown in Plate LXIV, Fig. 7, taken from Kurz. This may be termed an ephippium, although it differs somewhat from the modified shell so called in Daphnia. The male element consists of nearly round nucleated cells, and the opening of the vas deferens is anterior to the terminal claws. —— 1 Harporhynochus is preoccupied in ornithology. ENTOMOSTRACA OF MINNESOTA. 261 The members of this genus are among the most minute forms of the family or the entire group. Concisely put, the characters are as follows: Form globose, not obviously truncate behind; head terminating in a Sharp, long, curved beak, which lies close upon the anterior margins of the valves; antenne short; eye larger than the pigment fleck; abdo- men flattened, excavated in the male; intestine with no anterior ceca, _ doubly convoluted, with an anal cecum. Three species found in Min- nesota. * Chydorus sphzericus Mueller. PLATE LXIV, Fies. 4, 7, 8; 10. Lynceus sphericus—O. F. Miller, M. Edwards, Koch, Zaddach, Lieven, Fischer, Lill- jeborg, Leydig, Toth, Zenker, Fric. Monoculus sphericus—J urine. Chydorus muelleri—Leach. Form nearly spherical, as seen from above broadly oval; in young Specimens truncate behind; antennules of moderate size, in the male very large, with curved flagellum near the middle of anterior margin; pigment fleck often nearly as large as eye; beak of moderate length, blunt in the male; first foot strongly hooked in the male; post-abdomen Short, broad, rounded at the end, armed with eight or nine sharp teeth; shell reticulated with polygonal meshes. Color light, unspotted. Length 0.50 mm. This species occurs in spring earlier than most forms, and is ranked as the most abundant of the micro-crustacea, being found over the whole circumpolar land-area. The ephippium for the winter egg was observed by Kurz, but the period at which it isformed seems variable. C. spheericus of a previous report seems to have been the following species, which is more common in Minnesota in the clearer lakes. A small form in our large lakes measures 0.5 mm.; it may be distinct. * Chydorus globosus Baird. PLATES XXI, Fic. 23; LXIV, Fies. 1-3, 9. Form globose, very broad; antennules very large with a strong lat- eral seta on a small elevation; swimming antenne exceedingly small; the shell gland is well developed; the pigment fleck is much smaller than the eye; beak very long and incurved; post-abdomen rather long, more slender than the last, broader near the end which is truncate, bearing about 20 spines on the margin near which is a lateral series of minute bristles; the terminal claws are straightish, spined along the basal half, and have an accessory spine; the shell is very indistinctly 262 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. reticulated and spotted; color dark; length 0.7 to 0.8 mm.; male 0.55 mm. The males have the abdomen very narrow for the entire length. This species is considered rare elsewhere, but is not infrequent near Minneapolis during August. Chydorus ovalis Kurz. PLATE LXIV, Fia. 11. Form oval, nearly twice as long as high; beak long; antennules two-thirds as long as the beak, with one elongated sensory filament above the others; pigment fleck nearly as large as the eye; antenne small; shell margins heavily fringed anteriorly; post-abdomen of mod- erate size, rounded at the end, with about eight teeth near the end; shell smooth. Length 0.4 mm. This species is rather near C. sphericus, differing in having the shell smooth, antennz shorter and beak longer. This species is not yet known in America. From C. Jatus it differs in the single anten- nulary flagellum and number of anal teeth. * Cbhydorus czelatus Schoedler. PLATE LXIV, Fie. 12. Chudorus adunctus—Schoedler. This small species is about 0.4 mm. long and resembles the young of C. globosus in form, from which as well as from all known species it is distinguished by the markings of the shell, which consist of series of rounded elevations (or depressions?) arranged parallel to the lower margins of the shell and head. The description is very incomplete, and the only other author who appears to have seen the animal is Kurz, who adds that the sensory filaments of the antenne are unequal in height, and that the so-called elevations are really depressions. A form with a few depressions about the edge and characters of this Species was once seen in the vicinity of Minneapolis. This is probably a variety of C. sphericus. Chydorus nitidus Schoedler. PLATE LXIV, Fies. 5, 6. Shell smooth and regularly punctate; the head resembles ©. speri- cus, but the pigment fleck is much smaller than the eye, to which it is much nearer than to the end of the beak; the post-abdomen is broader near the end, and bears a row of 10 to 12 teeth on either side. Chydorus latus Sars. Of moderate size, oval, rounded behind. A slight depression be- tween head and body. Beak long, slender and curved. Macula quad- %; a PY ae ade ENTOMOSTRACA OF MINNESOTA. 263 rangular, smaller than the eye and half as far from it as from the beak. The conical antennules bear two flagella, one near the end, the other near the basal third. Shell longer than high, strongly arched above. surface smooth. Anal teeth 13 or 14. Claws short and smooth except for the two basal spines. (Matile says the claws are slightly ciliate.) Length 0.54 to 0.59 mm. Chydorus piger Sars. Sub-rotund, prominent above, sinuate behind; lower and posterior margins rounded, lower margin ciliated. Head movably united to the body; beak long, separated by an indentation from the head shield. The shell is broad, as seen from above. Shell punctate anteriorly and marked below by indistinct oblique strie. Antennules with seven sets and two small thorns on the end of each ramus. Post-abdomen truncate; the terminal claws with a minute tooth at the base, posterior margin sinuated, rounded below and there densely armed with minute teeth. Abdominal sete long and flexible. Pig- ment fleck of medium size, much nearer to the eye than to the beak. Length about 0.33 mm. (2?) Chydorus latifrons Dana. (U. S. Exploring Expedition, Rep. on Crust., Vol. II, p. 1274.) Very tumid; inside view rotund, head not separate, very short- beaked; beak slender and close to the body, acute; in upper view animal very broad, truncate anteriorly, the front thereby nearly as broad as the body; behind low, triangular and obtuse. Feejee Islands. (?) Chydorus albicans Gay. From Chili. Is imperfectly described; but it is interesting to note the occurrence of this genus there. Chydorus punctatus Hellich. Very small, tumid, truncate caudad. Head low, with rather short, sharp beak. Macula round, as large as the eye, to which it is nearer than the beak. Antennules tumid at the middle, with lateral seta above the middle. The ventral margin of the shell is very convex, with long pectinate sete. Hexagonal reticulations, each with a cen- tral elevation (?) mark the shell. Post-abdomen short, broad. Anal teeth eight or nine, of uniform size. Claw with one basal spine and a row of sete. Length 0.44 to 0.47 mm. The abdomen of the male is curved and deeply excavated apically. Claws short and smooth. Length 0.42 mm. This is probably only a variety of C. sphericus. 264 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. Chydorus letourneuxi Richard. Richard ’88. Testa a latera visa subrotundaia, sulcis curvatis (10-12) e medio exeuntibus, ad margines anticos liberos porrectis, antice manifestis ut in Plewroxus adunco, ornato; testis cetera levis, margine superiore prominente, postice Jeviter sinuato, marginalibus posterioribus et inferioribus rotundatis. Valoulorum margines inferiores postice ciliis longis instructi, margines superiores dentati. Rostrum breve et obtusum. Antenne 1 mi paris ad basin crassie, rostro breviores, setis equalibus. Antenne 2 di paris setis 7 preditze. Macula nigra oculo duplo minor, inter oculum et apicem rostri fere in medio sita. Postabdomen apicem versus rotundatum, unguibus termi- nalibus brevibus levibus ac robustis, aculeis ad basin 2, quorum interior altezo multo brevior, armatis; margo superior in medio sinuatus supra medium processum obtusum format et infra hune aculeis minutis dense obsitus. Spinulis mintutissi- mis sparsim in lateribus post-abdomen instructum. Color corneus. Longit. circit 0.5 mm. Mas ignotus. Algeria and Tunis. Chydorus alexandrowii and C. tuberculatus ef Poggenpol are confess- edly imperfectly described. We incline to the belief that there are not more than four good species in this genus, but extended study of the conditions of variation are necessary. GENUS ANCHISTROPUS Sars. (?) Very similar in form to Chydorus; valves gaping below anteriorly; antennules small; process of labrum rounded. Post-abdomen atten- uated toward the end, densely covered with fine teeth; terminal claws denticulate. First foot with a powerful claw, protruding beyond the shell. Eye very large. Shell indistinctly reticulate. Sars says of his Anchistropus emarginatus that on cursory inspection it would be taken for the young of Chydorus globosus. He found but few speci- mens, about 0.35 mm. long. The suggestion is still possible that the young males of some Chydorus are here mistaken for a new genus. The males of Chydorus globosus were not known till 1878, and their early form is still unknown. The young females have a tolerably strong claw, though it is not much curved. I once found a peculiar Zynceid measuring 0.46 mm., with unevenly but distinctly reticulate shell, slender abdomen, and a strong claw which was dentate. There were several young (more than two), and the shell in these was more regularly reticulate. All efforts to find a second specimen failed, and the one seen was somewhat mutilated; hence I am unable to determine its real position. GENUS MONOSPILUS Sars. Head separated by a depression from the body; shell high, com- pressed, posterior margin somewhat less than the greatest height of the shell. Post-abdomen broad, ornamented with lateral and posterior ENTOMOSTRACA OF MINNESOTA. 265 spines; claws large, with a single basal tooth. The compound eye is absent, its place being taken by the pigment fleck, which is the func- tional eye.* *Monospilus tenuirostris Fischer. PLATE LXII, Fie. 21, 21a. Fischer ’54 (Lynceus tenuirostris); Sars 61; Norman and Brady ’67; Mueller ’68; Hellich ’77; Herrick ’84 and ’87 (dispar). Shell roundish; ventral margin setose; posterior angle rounded, marked above with numerous impressions. Antennules small; anten- nz long, with seven set. Post-abdomen short and broad, bearing a series of spines along the excavated posterior margin, and ornamented on the sides with clusters of bristles. The shell in old individuals is not moulted but remains as in Ilyocryptus, covering the greater part of the new shell. The figure shows an old individual with its succes- sive coverings still clinging to it. Like I/yocryptus, this animal passes its life in filth at the bottom of pools and rarely emerges to the light of day. What little visual function there may be is vested in the larval organ. The specimen from which the drawing was made measured 0.45 mm. The first glance at this rarest of all entomostraca affords proof of its unique character. The strongly arched shell is so compressed as to bear little resemblance to Chydorus. The dorsal line passes with little angle into the high posterior margin. There is a rounded angle below, armed with two teeth—the shortened representatives of the fringing spines of the straight lower margin. The head is depressed and very short; but the narrow beak is produced to below the margin of the valves. It is rounded so as to resemble, as seen in front, a duck’s bill. The fornices are narrow and flare so that the eye is left partly exposed upon the side. The antennules are not long but slender. The labrum has a very large lamella, which is crenulate in front and acute below, the labrum proper being large. The systematic positioa of this genus is a matter of considerable interest, for it is the only member of the whole order in which the larva! eye is the only one *So much interest attaches to this species that we reproduce the latin description of Sars: ‘ Testa in adultibus valyulis composita pluribus, altera alteri imposita, a latere visa lata, latitudine maxima in parte antica sita; margine superiore antice valde prominente, posteriore et inferiore ciliato rotundatis. Caput mobile, perparvum et valde depressum, supine impressione parva sed distincta, a testa cetera dis- ear al deorsum in rostrum rectum et breve apice obtuso exiens. Animalsupravisum sat compressum, atitudine maxima capite majore ante medium sita. Pars superior testz et capitis impressionibus nume- rosis rotundatis notata. Antenne 1-mi paris minute structura ut in ceteris Lynceidis; 2-di paris sat long, ramo altero setas 4 et aculeum unum apicalem altero setas 8 et aculeos duos,quorum alter longus articulo primo ejusdem rami adfixus est, gerunte. Postabdomen breve et latum, apicem versus truncatum; margine posteriore supra obtuse angulato, ad angulum inferiorem rotundatum seriebus duabus aculeo- rum ingue lateribus setis vel spinulis brevibus numerosis preditum; ungues terminales ad basin aculeo longo armati. Intestinum, ut in ceteris Lynceidis, in thorace laquem fere duplicem format. Macula nigra unica minima prope basin antennarum 2-di paris; macule infra oculari in ceteris Lynceidis simiilima, in capite conspicitur, que, quum oculus verus compositus in omnibus ceteris Crustaceis Cla- doceris distinctus omnino absit, organum quamquam rudimentare visus habenda est. Animal parum pellucidum, colore fulvescente. Longit. parum supra 4 mm.” + Se Rc ee + 266 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. developed, and the first thought would be that this must be a primi- tive synthetic type; inother words, historically the oldest of Cladocera. Closer study does not warrant the theory. There is much to indicate that, though essentially lynceid, it stands in close connection with, the higher members of the family and perhaps has more than a superficial resemblance to such degraded Lyncodaphnids as Ilyocryptus. All things considered, however, our diagram stands with this genus as a degraded offshoot of the more typical stem of Lynceide. SUB-ORDER GYMNOMERA. This group is easily recognized by the almost entire absence of the shell, which forms so conspicuous a part in the greater number of the Cladocera. Here it serves simply to form a pouch or brood-sae for carrying the eggs and embryos. The feet are nearly terete and pre- hensile, with but slight indications of branchial appendages. FAMILY POLYPHEMIDE. Feet five pairs. Antenne with the rami three- or four-jointed. GENUS POLYPHEMUS De Geer. Head very large, separated by a depression from the compact body; shell covering but a part of the dorsal region. Feet all with an inter- nal dentate and an external lamellate appendage. Caudal seta upon a long process of the post-abdomen. * Polyphemus pedicuius Linn. PuLates LVIII, Fies. 4-6; LXIX, Fie. 1. Monoculus pediculus—Linnzus, 1746. Gmelin, Linn. Syst. Nat. Fabricius, Ent. Syst., etc. Sulzer, Insecten. Manuel, Encyclop. Meth. Monoculus pediculus ramosus—De Geer, Mem. pour serv. a |’ Hist. des. Ins. Polyphemus oculus—Mueller, Zool. Dan. Prod. et Entomost. Cuvier, Tab, element. Latreille, Hist. Nat. Crust., ete. Leach, Edin. Encye. Polyphemus stagnorum— Leach, Dict. Sc. Nat. Latreille, Cuv. Reg. An. Demarest, Cons. Gen. Crust. Polyphemus pediculus—Straus, Mem. Mus. d’Hist., etc. M. Edwards, Hist. Nat. Crust. Monoculus polyphemus—Jurine, Hist. Nat. Monoc. Cephaloculus stagnorum—Lamarck, Hist. An. Vert. Bosc, Man. d’Hist. Nat. Crust. Monoculus oculus—Gmelin, Linn. Syst. Nat. Scalicerus pediculus—Koch, Deutsch. Crust. Polyphemus pediculus—Baird, Brit. Entom. Polyphemus oculus—Lievin, Branch. d. Danz. Polyphemus stagnorum—Fischer, Ueber die in d. Umg. von. St. Petersburg vorkom Crust. ENTOMOSTRACA OF MINNESOTA. 267 Polyphemus pediculus—Liljjeborg, De Crust. ex ord. trib. Polyphemus oculus—Leydig, Naturg. d. Daph. Polyphemus pediculus—Schoedler, Neue Beitr. zur Naturg. d. Cladoceren. Polyphemus kochii—Schoedler, Neue Beitr. zur Naturg. d. Cladoceren. Polyphemus oculus—Schoedler, Neue Beitr. zur Naturg. d. Cladoceren. Polyphemus pediculus—P. E. Mueller, Danmark’s Cladecera. Kurz, Dodekas neuer Cladoceren. Weismann, Beitr. zur Naturg. der Daphnoiden. Birge, Notes on Cladocera. Polyphemus occidentalis—Herrick. There are two well-marked varieties of this species: one is found commonly in the clear lakes; the other, which I have only once seen, was found in avery shallow weedy marsh. The difference in size is quite remarkable. Our ordinary form measures less than 1.0 mm. The larger form, including the stylets, is 1.6 mm. The ordinary variety, although highly colored, is yet transparent, while the large variety is deep red and quite opaque. The relationship between the two forms is quite like that maintaining between Diaptomus stagnalis and D. sanguineus. Some slight structural differences are observable between the two varieties, as in the form of.the antennules, yet quite insignificant when compared with the striking difference in size and coloration. The feet of this species have not been fully figured hitherto and are accordingly given on Plate LXIX. Some minor differences may be noted between these figures and those given by Lund. *Polyphemus stagnalis Herrick. In order to make the relation clear between these forms, I add measurements of this species, following each with the corresponding measurement of P. pediculus in parenthesis; animals of the same age, as far as possible, being chosen. Head (capsule of eye) 0.3 mm. (0.2 mmm.); head and thorax 0.7 mm. (0.45 mm.); abdomen 0.7 mm. (0.56 mn. ); caudal stylet 0.36 mm. (0.26 mm.); caudal filaments 0.36 mm. (0.3 mm.) Whole length of antenne 0.54 mm. (0.42 mm.); first, second and third joints of the three-jointed ramus 0.08, 0.06 and 0.10 mm., respectively. The formation of the resting eggs or ‘‘dauer-ei”’ seems to go on at the same time with the parthenogenetic repro- duction. GENUS BYTHOTREPHES Leydig. Much like Polyphemus, but the external appendage of the feet is rudimentary, and the abdomen extends out into a most enormous spine. The single species is that described by Leydig as B. longimanus, which was found in the stomach of Coregonus wartmanni. B. ceder- stromii of Schoedler and P. E. Mueller, the latter author now identifies — 2 + cai ‘ ac: _ 268 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. with the above, and concludes that the supposed differences arose from ‘‘Vetat de maceration des exemplaires examines.’’ (Les Cladoceres des Grands Laces de la Suisse, p.11.) This species may be looked for in the depths of the Great Lakes. (See Plate XX VII, Fig. 10.) GENUS PODON and GENUS EVADNE. These are compact oval forms confined to the sea. See Claus, Zur Kenntniss des Baues der Polyphemiden, Vienna, 1877, for the best account of the anatomy. FAMILY LEPTODORID#. Feet six pairs. Antenne with both rami four-jointed. Body elongated, not curved, shell very much reduced. *Leptodora hyalina Lilljeborg. PLATE XXXYV, Fias. 6, 7. The only species, is found rarely in the larger lakes of Europe and America. See Bau und Lebenserscheinung von. Leptodora hyalina, Weismann, 1874; also, Omen dimorph Udvikling samt Generationsvexel hos Leptodora, G. O. Sars, 1873; also, Bidrag til Cladocerenes Forplantningshistorie, P. E. Mueller. The work of Sars is particularly valuable, showing that the young produced from the winter eggs pass through a metamorphosis not ex- perienced by the summer or parthenogenetic brood. P. E. Mueller mentions the pathological condition induced by the plants of the Saprolegnia. oo” 4 ae PEN DLX TO PARE OF THE UTHEASTERN PART OF THE UNITED STATES BY Cc. H. TURNER . ae ORDER CLADOCERA. FAMILY SIDID. GENUS SIDA Straus. Sida crystallina Miiller. Sida erystallina—C. L. Herrick, Final Report on Minn. Crust., p. 20. Habitat: Cincinnati, Ohio. Rare. Occurs in deep canal basins. FAMILY DAPHNIDE. GENUS MOINA Baird. Moina rectirostris Miiller, Moina rectirostris—C. L. Herrick, Final Report on Minn. Crust., p. 34; Pl. A., Figs. 2) 5; 85-10; 11: Length of female 0.94 mm.; height 0.63 mm. Habitat: Atlanta, Ga. Moina paradoxa Weismann. Moina paradoxa—C. L. Herrick, Final Report on Minn. Crust., p. 34; Pl. A, Figs. 1, 3, 6, 7, 9. Habitat: Cincinnati, Ohio. During the latter portion of summer this species is very abundant in foul pools. GENUS CERIODAPHNIA Dana. Ceriodaphnia consors Birge. | Ceriodaphnia consors—E. A. Birge, Notes on Clad., p. 5; Pl. 1, Figs. 3, 4. Length 0.55 mm.to 0.61 mm.; height 0.40 mm. The reticulations onthe shell aresingly contoured. Habitat: Atlanta, Georgia. Winter and summer. Ceriodaphnia megops Sars. Ceriodaphnia cristata—E. A. Birge, Notes on Clad., p. 6; Pl. II, Figs. 8, 9. Length 0.64 mm.; height 0.50 mm. Habitat: Kent county, Dela- ware; Atlanta, Georgia. 272 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. GENUS SCAPHOLEBERIS Schoedler. Scapholeberis mucronata Miiller. Scapholeberis mucronata—C. Li. Herrick, Final Report Minn. Crust., p. 42; Pl. J, Fig. 5. Habitat: Atlanta, Georgia; Cincinnati, Ohio; Lockland, Ohio. Abundant in shallow grassy ponds and sluggish creeks. GENUS SIMOCEPHALUS Schoedler. Simocephalus vetulus Miiller. Simocephalus vetulus—C, L. Herrick, Final Report Minn. Crust., p. 46. Habitat: Cincinnati, Ohio; Kent county, Delaware. Simocephalus serrulatus Koch. Simocephalus americanus—E. A. Birge. Notes on Clad., pp. 6-8; Pl. I,Fig. 6, Length 1.7 mm. to 1.9 mm.; ‘height 1.43 mm. This species is often covered with vorticellide. Habitat: Atlanta, Georgia; Baxley, Georgia; Cincinnati, Ohio; Kent county, Delaware. GENUS DAPHNIA Schoedler. * Daphnia pulex Miiller. Dapnnia pulec—C. L. Herrick, Final Report Minn. Crust., p. 56. Habitat: Cincinnati, Ohio; Covington, Kentucky. This species is fond of foul water and is often associated with Moina paradowa. Daphnia longiremus Sars. (?) Daphnia longiremus Sars—C. L. Herrick, Final Report Minn. Crust., p. 63. Length 1.70 mm. This is a non-crested, hyaline specimen, marked with rectangular meshes and devoid of pigment fleck. It resembles the species under which I have placed it in all respects excepting siez. I do not consider this alone sufficient to establish a new species. It may, however, be a variety of the above. FAMILY BOSMINIDE. GENUS BOSMINA Baird. Bosmina cornuta Jurine. Bosmina cornuta—E. A. Birge, Notes on Clad., p. 15; Pl. II, Fig. 10. Length 0.26 mm. Habitat: Tusculum, Ohio. Rare. Found} in grassy pools. ENTOMOSTRACA OF MINNESOTA. 2S Bosmina atlantaensis Turner. Bosmina atlantaensis—C. H. Turner, Notes on the Clad. of Ga., p. 23; Pl. VII, Figs. a Paley Length 0.46 mm.; height 0.36 mm. Habitat: Atlanta, Georgia. Obtained in the middle of winter from pools that dry up in dry weather. FAMILY LYNCODAPHNIDE. GENUS MACROTHRIX Baird. Macrothrix laticornis Jurine. Macrothrix laticornis—C. L. Herrick, Final Report Minn. Crust., p. 68; Pl. C, Figs. 8, 9. Length 0.37 mm. to 0.39 mm.; height 0.25mm. Habitat: Atlanta, Georgia. GENUS ACANTHOLEBERIS Lilljeborg. Acantholeberis curvirostris Miller. Acantholeberis curvirostris—C. L. Herrick, Final Report Minn. Crust., p. 73. Length 0.97 mm.; height 0.61 mm. Habitat: Baxley, Georgia. GENUS ILYOCRYPTUS. Ilyocryptus sordidus Lievin. European observers have never found more than a few specimens of this species at any one time. At two different times this summer I have found this species in great numbers in the mud at the bottom of a small pool on the Clark University campus at South Atlanta, Georgia. This pool is a tank about four feet deep, fed by a cool spring. At one end a shallow grassy creek flows outward from it. This creek at its origin is less than a foot deep and has a mud bottom. In this creek, at its source, is where the specimens were obtained. The American specimens tally in all essential respects with the European specimens. Habitat: South Atlanta, Georgia. Ilyocryptus longiremus Sars. llyocryptus longiremus—E. A. Birge, List of Crust. Clad. from Madison, Wis., p. 392; Pl. XIII, Fig. 18. This species agrees in all essential respects with the species found by Professor Sars in Australia and by Professor Birge in Wisconsin. Habitat: Baxley, Georgia. It seems to be present in almost all of the ponds near Baxley. This species is very closely related to Ilyocryptus spinifer Herrick. At one time I was fully convinced that they were two distinct species, 274 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. but the more I study this species the more I am led to believe that this and J. spinifer are varieties of one and the same species. If this surmise be true then Professor Herrick’s name has precedence. FAMILY LYNCEID. SUB-FAMILY EURYCERCINE. GENUS EURYCERCUS Baird. Eurycercus lamellatus O. F. Miiller. Eurycercus lamellatus—C. L. Herrick, Final Report Minn.Crust., p. 80; Pl. H, Figs. 5, 6. Length 1.67 mm.; height 1.16 mm. Habitat: Kent county, Dela- ware. SUB-FAMILY LYNCEINE. GENUS CAMPTOCERCUS Baird. Camptocercus macrurus O. F. Miiller. Camptocercus macrurus—E. A. Birge, Notes on Clad., p. 33. The specimen here tabulated under this genus is smaller than those found by Professor Birge in Wisconsin and by Professor Herrick in Minnesota; but, since they agree with Professor Herrick’s description in all other respects, it is thought that this is the right place for it. Habitat: Lockland, Ohio. Length 0.63 mm.; height 0.42 mm. GENUS LEYDIGIA Kurz. Leydigia quadrangularis Leydig. Leydigia quadrangularis—C. L. Herrick, Final Report Minn. Crust., p. 88; Pl. H, Fig. 4 Length 1.00 mm.; height 0.5mm. Habitat: Clifton, Ohio; Lock- land, Ohio; Atlanta, Georgia. GENUS DUNHEVIDIA King. Dunhevidia Setiger Birge. Orepidocercus setiger—E. A. Birge, Notes on Clad., p. 26; Pl. I, Fig. 18. Length 0.43 mm.; height 0.31 mm. Habitat: Cincinnati, Ohio. GENUS ALONA Sars. Alona quadrangularis Miiller. Alona quadrangularis—C., L. Herrick, Final Report Minn. Crust., p. 97; Pl. E, Figs. 1, 2. Length 0.76 mm.; height 0.46 mm. In the specimen here assigned to the above named species the pigment fleck is as large as the eye and:the spine on the terminal claw of the post-abdomen is pectinate at its base. Habitat: Baxley, Georgia. , a ENTOMOSTRACA OF MINNESOTA. 275 Alona affinis Leydig. Alona affinis—C. L. Herrick, Final Report on Minn. Crust., p. 98; Pl. F, Fig. 14. Length 0.79 mm.; height 0.46 mm. The specimens here tabulated are smaller than those found by other writers; but since they agree in all essentials with A. affinis they are placed here. In all probability they are immature individuals. Habitat: Kent county, Delaware; Fayetteville, Georgia. Alona porrecta Birge. Alona porrecta—E. A. Birge, Notes on Clad., p. 29; Pl. I, Fig. 16. 3 Length 0.37 mm. to 0.58 mm.; height 0.22 mm. to 0.24 mm. Habi- 4 tat: Atlanta, Georgia; Cincinnati, Ohio. Alona glacialis Birge. Alona glacialis—E. A. Birge, Notes on Clad., p. 30. Habitat: Cincinnati, Ohio. Rare. yee ee ys ee Pe iS Alona intermedia Sars. _ Alona intermedia—C. L. Herrick, Final Report Minn. Crust., p. 101; Pl. I, Fig. 15. 3 Habitat: Cincinnati, Ohio. rn GENUS PLEUROXUS Miller. e- Pleuroxus acutirostris Birge. 4 Pleuroxus acutirostris—E. A. Birge, Notes on Clad., p. 23; Pl. II, Fig. 15. This species seems to be very rare. I have only encountered it E once. Then it was associated with Pleuroxus hamatus Birge, which it _ closely resembles in shape. The specimen resembled in all respects ’ the specimens described by Professor Birge. Habitat: Atlanta, «Georgia. 5, Pleuroxus hamatus Birge. . Pleurowus hamatus—E. A. Birge, Notes on Clad., p. 22; Pl. II, Figs. 13, 14. Length 0.46 mm. to 0.52 mm.; height 0.23 mm. to 0.33 mm. Habi- ; tat: Cincinnati, Ohio; Atlanta, Georgia. In the northern part of Georgia specimens of this species are more plentiful than those of any other member of this genus. Pleuroxus denticulatus Birge. Pleuroxus denticulatus—E. A. Birge, Notes on Clad., p. 20; Pl. I, Fig. 21. Length 0.57 mm.; height 0.43 mm. Habitat: Cincinnati, Ohio; Kent county, Delaware; Atlanta, Georgia. ‘, 18 276 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. GENUS CHYDORUS Leach. Chydorus sphezericus Miiller. Chydorus sphericus—C. L. Herrick, Final Report Minn. Crust,, p. 116; Pl.| F, Figs. 4, 7, 8, 10. Length 0.36 mm. to 0.42 mm.; height 0.31 mm. to 0.36 mm. Habi- tat: Ohio, Kentucky, West Virginia, Georgia. This species is very abundant. At Atlanta, Georgia, it can be found any time during the year. FAMILY POLYPHEMIDE. GENUS POLYPHEMUS De Geer. Polyphemus pediculus De Geer. Polyphemus pediculus—C. L. Herrick, Final Report on Minn. Crust., p. 121; Pl. B?, Figs. 4-6. Habitat: Baxley, Georgia. Ree +30 Rad ra ss Soles . = Por THE UNITED SPATHS Bye CE et URINE R PREFACE. Perhaps no other class of animals has been so much neglected by scientists as the American Ostracoda. With the European Ostracoda it is quite different. In Great Britain, Norway, Germany, Bohemia and along the shores of the Mediterranean Sea able naturalists have devoted many years of their life to the study of the Ostracoda of their respective countries. A perusalof the bibliography given below will show how well they have done the work. In his late monograph (221) Professor Wenzel Vavra devotes several pages to a historical resumé of the work that has been done upon the European Ostracoda. A1l that has been done upon the recent American Ostracoda can be included in a Single paragraph, and a small one at that. The first scientist to study American Ostracoda was De Kay (58). In 1844 he described a few specimens from New York. This was fol- lowed in 1852 by an article by Professor Dana (57). In 1855 Lubbock (123) published a short article on South American Ostracoda. Next comes a paper by Chambers (41) on Colorado Crustacea. Between 1879 and 1881 Professor Herrick (83, 84, 85, 86) published several papers on this subject. His paper on ‘‘Alabama Crustacea” is by far the best article yet published on recent United States Ostracoda. Professor Moniez (142) has recently added a paper on Lake Titicaca Crustacea. Between 1892 and 1894 the present writer has contributed his mite (212, 213, 214, 215, 216) towards furthering the good cause. In 1893 Forbes (67*) published a description of a new species. The fossil Ostracoda have been studied by Jones (89,92) Brady (29) and Ulrich (217). In the present communication it is proposed to give complete de- scriptions of all known recent United States Ostracoda. In most cases the descriptions are made from dissections made by the writer. When this has not been possible the description of some American author has been incorporated. In all such cases the description is surrounded by quotation marks and the name of the author is mentioned. I here tender my thanks to Messrs. A. B. Whitby and L. D. Hile- land, who have so kindly collected for me material which otherwise would have been inaccessible. Mr. Whitby collected in Texas and southern Georgia, while Mr. Hileland collected in Delaware. I here acknowledge my great indebtedness to Professor C. L. Her- rick, not only for the loan of rare literature and for the use of Plates LX, LXIII, LXIV, but also for the careful drawings of Cypris albu- querquensis and for alcoholic specimens. 280 >) = GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. BIBLIOGRAPILY. Baird, W. 1. Trans. Berw. Nat. Club., Vol. I, 1835. 2. Natural History of the British Entomostraca. (Mag. Zool. and Botany, Vol. II, 1838, p. 132.) 3. Description of some new species and genera of British Entomostraca. (Ann. and Mag. Nat. Hist., Ser. I, Vol. XVII, 1846, p. 410.) .4, Notes onthe genus Cypridina, M. Edw. with description of two new species. , (Ann. and Mag. Nat. Hist., Ser. I, Vol. I, 1848, p. 21.) 5. Natural History of the British Entomostraca. (Ray Society, 1850.) 6. Description of several new species of Entomostraca. (Proc. Zool. Soc., Lon- don, Vol. XVIII, 1850, p. 254.) 7. Monograph of the family Apodidz and description of two new species of Cypris. (Proc. Zool. Soc., London, Vol. XX, 1852, p. 1.) 8. Some new species of Cypridina. (Ann. and Mag. Nat. History, Ser. III, Vel- VI, 1860, p. 139; and Proc. Zool. Soc., London, Vol. XXVIII, 1860, p. 200.) Barrois, Th., and R. Moniez. 9. Matériaux pour servir a ]’étude de la faune des eaux douces des Acores. IV. Crustacés. Lille, 1888. 20 pp. Bosquet, J. 10. Description des Entomostracés fossiles des terrains tertiares de la France et de la Belgique. Bruxelles, 1850. Brady, G. S. 11. Species of Ostracoda new to Britain. (Ann. and Mag. Nat. Hist., Ser. III, Vol. XIII, 1864, p. 59.) 12. Undescribed Fossil Entomostraca from the Brick-earth of the Nar. (Ann. and - Mag. of Nat. Hist., Ser. III, Vol. XVI, 1865.) 13. Report on the Ostracoda dredged amongst the Hebrides. (Brit. Assoc. Report, 1866, p. 208.) 14. New and imperfectly known species of Marine Ostracoda. (Trans. Zool. Soc., London, Vol. V, 1866, p. 359.) 15. Entomostraca. (Intellectual Observer, 1862, p. 446.) 16. Synopsis of recent British Ostracoda. (Intellectual Observer, 1867, p. 110.) 17. Crustacean Fauna of the Salt Marshes of Northumberland and Durham. (Nat. Hist. Trans. Northumberland and Durham, Vol. III, 1868, p. 1.) 18. Monograph on Recent British Ostracoda. (Trans. Lin. Soc., Vol. XXVI, 1868, p. 353.) 19. Contribution to the study of Entomostraca. (Ann. and Mag. Nat. Hist., Ser. IV, Vol. II, 1868, pp. 30, 178, 220; Vol. III, 1869, p. 45; Vol. IV, 1870, p. 450.) 20. Descriptions of Ostracoda. (Berchon, De Folin, and Perier, Les Fonds de la Mer., Vols. I, II, and IV, 1867-86.) 21. Notes on the Ostracoda. (Nares’ Narrative of a Voyage to the Polar Sea, 1875-6, in H. M.S. S. ‘‘Alert’’ and ‘‘Discovery,’’ 1878, p. 253.) ENTOMOSTRACA OF MINNESOTA. 281 22. Notes on Entomostraca taken chiefly in the Northumberland and Durham dis- trict. (Nat. Hist. Trans. Northumberland and Durham, Vol. III, 1870, p. 361.) 23. Review of the Cypridinidz of the European Seas. (Proc. Zool. Soc., 1871, p. 289. ) 24, Monograph of the Ostracoda of the Antwerp Crag. (Trans. Zool. Soc., Vol. X, 1878, p. 379.) 25. Report Voyage of H. M. S. ‘‘Challenger’’-— Ostracoda, 1880. 26. Notes on Entomostraca collected by Mr. A. Haly in Ceylon. (Lin. Soc. Jour- nal, Vol. XIX, 1885.) 27. Notes on Freshwater Entomostraca from South Australia. (Proc. Zool. Soc., 1886.) 28. Notes on Entomostraca. (Fifth Ann. Rep. Fishery Board of Scotland, Ap- pendix F, 1887, p. 328.) Brady, G. S., and Crosskey, W. H. 29. On Fossil Ostracoda from the Post-tertiary Deposits of Canada and New England. (Geol. Mag., Vol. VIII, 1871.) Brady, Crosskey, and Robertson. 30. .Monograph of the Post-tertiary Entomostraca of Scotland, and parts of Eng- land and Ireland. (Palzontographical Soc., 1874.) Brady and Norman. 31. A monograph of the marine and freshwater Ostracoda of the N. Atlantic and of N. W. Europe. Section I, Podocopa. (Trans. R. Dublin Soc., 1889.) Brady, G. S., and Robertson, D. 32. Notes on a Week’s Dredging in the West of Ireland. (Ann. and Mag. Nat. Hist., Ser. IV, Vol. III, 1369, p. 353.) 33. Ostracoda and Foraminifera of Tidal Rivers. (Ann. and Mag. Nat. Hist., Ser. IV, Vol. VI, 1870, p. 1.) 34, On the Distribution of British Ostracoda. (Ann. and Mag. Nat. Hist., Ser. IV, Vol. TX, 1872, p. 48.) 35, Ostracoda taken among the Sicily Islands, and on the Anatomy of Darwinula stevensoni. (Ann. and Mag. Nat. Hist., Ser. IV, Vol. XIII, 1874, p. 114.) 36. Report on Dredging off the Coasts of Durham and North Yorkshire. (Brit. Ass. Rep., 1875, p. 185.) Braun, M. 37. Faunistische Untersuchungen in der Bucht von Wismar. (Arch. Freunde Naturg. Mecklenburg, 42. Jahrg. 28 pp.) Brown, Dr. H. G. 38. Die Classen und Ordnungen des Thier-reichs. V. Bd. Arthropoda, I. Halfte. Crustacea von Dr. A. Gerstecker, Leipzig und Heidelberg, 1866-1879. Carriere, Dr. Justus. 39. Die Sehorgane der Thiere vergleichend-anatomisch dargestellt. 1885. Carus, J. V. 40. Prodromus Faune Mediterraneex. Arthropoda. 1885. Chambers, V. T. 41, On some new Entomostraca of Colorado. (Bull. United States Geological Survey, Vol. III, Art. IX.) 282 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. Chyzer, C. 42, Uber die Crustaceen-Fauna Ungarns. (In: Verhandl. d. k. k. Zoolog.-botan. Gesellschaft in Wien, p. 505, 1858.) Chyzer, C., and Toth, Alex. 43. Die Crustaceen der Pest-Ofener Gegend. (Naturfreund Ungarns, 1. Bd., 1857. 5. Heft, p. 84.) Claus, C. 44. Ueber die blassen Kolben und Cylinder an den Antennen der Copepoden und Ostracoden. (Witrzburg naturw. Zeitschr., 1. Bd., 1860, Taf. VII, Figs- 1, 2, 5.) 45. Ueber die Organisation der Cypridinen. (Zeits. f. wiss. Zool., Vol. XV, 1865, p. 143.) 46. Zur niheren Kenntniss der Jungenformen yon Cypris ovum. (Zeits. f. wiss. Zool., Vol. XV, 1865, p. 391.) 47. Ueber die Geschlechts differenzen von Halocypris. (Zeits. f. wiss. Zool., Vol. XV, 1865.) 48. Beitrage zur Kenntniss der Ostracoden. (Schrift. der Gesells. z. BefOrd. d., gesam. Naturwiss. zu Marburg, Bd. IX, 1868, p. 151.) 49. Neue Beobachtungen iiber Cypridinen. (Zeits. f. wiss. Zool., Bd. XXIII. 1873, p. 211.) 50. Die Gattungen und Arten der Halocypriden. 1874. 51. Untersuchungen zur Erforschung der genealogischen Grundlage des Crusta- 52. 53. ceen-Systems. Wien, 1876. Bemerkungen iiber Marine Ostracoden aus den Familien der Cypridinen und Halocypriden. (Arbeit. Zool. Inst. Wien und Zool. Stat. Trieste, T. VIII, Heft I, 1888, pp. 149-154. Wien. Uber die Organisation der Cypriden. (Ausz. im Anzeig. kais. Akad. Wiss. Wien. VIII, 1890, pp. 55-60. Costa, 0. G., and A. 53a. Fauna del Regno di Napoli. Crostacei. Daday, E. 54. Beitrage zur Kenntniss der Crustaceen-Fauna der Umgebung von Klausen- burg. (Berichte Klausenburger medicin.-naturw. 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Heft.) Garbini. 72. Contrib. all’ Anatomia ed alla Istologia delle Cypridinz. (Boll. Soc. Entom. Ital., XIX.) Giard, A. 73. Le laboratoire de Wimereux en 1888, recherches fauniques. (Bull. Soc. France. Belg., 1 Année, 1888, pp. 492-513.) Gissler, Chas. F. 74. Contributions to the Fauna of the New York Croton Water. Microscopic observations during the years 1870-71. (New York, 1872, 23 pp., 5 pl.) Guerne, J. de. 75. Note sur Ja faune des Acores. Diagnoses d’un Mollusque, d’un Rotifére et de trois Crustacé nouveaux. (Naturaliste, Paris, 1887, 7 pp.) 76. Compagnes scientifiques du yacht monégasque L’Hirondelle. 3 Année, 1887. Excursions zoologiques dans les iles de Fayal et de San Miguel (Acores). (Paris, 1888, 110 pp., 1 Taf.) 284 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. 77. Un Ostracode nouveau pour la faune francaise. La distribution geographique de Cypris bispinosa Lucas. (Revue Biol. Nord. France, 4 Année, 1893, No. 12, pp. 518-519.) Haldeman, C. 78, Proc. Phil. Acad., 1841 and 1842. Hallez, Paul. 79. Dragages effectués dans le Pas-de-Calais pendant les mois d’aofit et septembre 1888 et 1889. (Revue Biol. Nord. France, Lille, 1 Année, pp. 102-108; 2d Année, pp. 32-40.) Haupt. 80. Ueber Cypris im Allgemeinen nebst Beschreibung zweier neuer Arten. (Cor- respondenzbl. d. zoolog-mineralog. Ver. in Regensburg, 1850.) Heller, C. 81. Untersuchungen tiber die Crustaceen Tirols, 1870. Hellich, Boh. 82. O pohlavnim Ustroji rodu Cypris. (Oznamovatel I. sjezdu ceskych lékaru a prirodozpyteu, 1880. ) Herrick, C. L. 83. Microscopic Entomostraca. (Geol. and Nat. Hist. Survey of Minn., 7 Ann} Report, 1879, pp. 81-123; pl. I-X XI.) 84. On New Forms of Copepod and Ostracod Crustacea from the Fresh Waters of the State of Minn. (Ann. Rep. Geol. and N. H. Survey for 1881.) 85. On Notodromas and Cambarus. (Minn. Geol. and Nat. Hist. Survey, 10th Ann. Rep., 1882, pp. 252-254; 1 fig.) 86. 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. (Memoirs of Denison Scientific Ass., Vol. I, 1887, No. 1.): Imhof, 0. E. 87. Die pelagische Fauna und die Tiefseefauna der zwei Savoyerseen: Lac du Bourget und Lac d’Annecy. (Zool. Anz., 6 Jahrg., 1883, pp. 655-657.) Jeffreys, J. G. 88. Mediterranean Molluska and other Invertebrata. (Ann. and Mag. Nat. Hist.,. Vol. II, 1883, pp. 393-401, T. 16.) Jones, T. R. 89. Monograph on the Tertiary Entomostraca of England. (Palont. Soc., 1856.) 90. Notes on the Tertiary Entomostraca of England. (Geological Mag., Vol. VII, 1870.) 91. On some Fossil Ostracoda from Colorado. (Geological Mag., Decade II, Vol. IIT, 1886.) 92. Contributions to Canadian Micro-Palentology. 5. On Some Ostracoda from Cambro-Silurian, Silurian and Devonian Rocks. (Geol. Nat. Hist. Survey Canada, 1891, pp. 57-100, T. 10-13.) 93. On Rhetic and Liassic Ostracoda. (Quart. Jour. Geol. Soc., London, Vol. 50, 1894, P. II, pp. 156-168.) 94, Onsome Palzzoic Ostracoda from Westmoreland. (Quart. Jour. Geol. Soc., London, Vol. 50, P. II, 1894, pp. 283-295.) ENTOMOSTRACA OF MINNESOTA. 285 Jones, T. R., and Sherborn, C. D. 95. Further Notes on the Tertiary Entomostraca of England. (Geol. Mag., De- cade III, Vol. IV, 1887.) Joseph, Gust. 96. Erfahrungen im wissenschaftlichen Sammeln und Beobachten der den Krainer Tropfsteingrotten eigenen Arthropoden Berlin. (Separat-abdr. aus der Berliner entomologischen Zeitschrift, Bd. X XV, 1882, Heft II, und Bd. X XVI, Heft I.) Jourdain, S. 97, Recherches sur les poils 4 batonett de l’antenne interne des Crustacés, précé- dées de quelques remarques sur les poils dit Glfactifs. (Jour. Anat. Phys., 17 Ann,, 1881, pp. 402-418, F. 23 und 24.) Jurine, L. 98. Histoire des Monocles, qui se trouvent aux environs de Genéve, 1820. Kertesz, K. 99. Daten zur Ostracoden-Fauna der Umgebung Szeghalom’s. (Természetr. Fizetek, Bd. XVI, 1894, Hefts 3 u. 4.) Kerrville, G. de. 100. Les Crustacés de la Normandie, espéces fluviatiles, stagnales e terrestres. Bull. Soc. Amis Sc. N. Rouen, 1888, pp. 133-158.) King, R. L. 101. On Australian Entomostraca. (Proc. Roy. Soc. Van Diemen’s Land, Vol. III, pt. 1, 1855.) Koch, C. L. . 102. Deutschlands Crustaceen, Myriopoden und Arachniden, Heft 10, 1837; H. 11, 1837; H. 12, 1837; H. 21, 1838; H. 36, 1841.) Kolmodin, L. 103. Ostracoden silurica Gotlandiz cum tab. (In Ofvers. k. vet. Akad., Forhdlgr. Stockholm, 1879, No. 9, pp. 133-139.) Korschagen, A. N. 104, Fauna of the neighborhood of Moscow, Entomostraca-Malacostraca, 1887. 4to (in Russian), Krause, Aurel. . 105, Die Ostracoden der Silurischen Diluvialgeschiebe. (Berlin, 1891, 24 pp.) 106. Beitrag zur Kenntniss der Ostracoden-Fauna in Silurischen Diluvialge- schieben, mit 5 Taf. (Zeits. d. deutsch. Geol. Ges. 43 Bd., 2 Hft., pp. 488-521.) 107. Neue Ostracoden aus mirkischen Silurgeschieben, mit 2 Taf. (Zeits deutsch. Geol. 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(Verhdlgn. natur- hist. ver. preuss. Rheinl., 49 Jahrg., 1893, 1 Halfte Korr.-Blatt, pp. 58-59.). Lievin. 117. Die Branchipoden der Danziger Gegend. Ein Beitrag zur Fauna der Provinz Preussen. (4° mit 11 Taf., Danzig, 1848.) Lilljeborg, W. 118. De Crustaceis ex ordinibus tribus Cladocera, Ostracoda et Copepoda in Scania. occurrentibus, 1853. 119. Beskrifning ofver tva Grter Crustacea af ordningarna Ostracoda och Copepoda. (Ofvers. af K. Vet. Akad. Iorhand, 1862, p. 291.) 120. Collections of chiefly Freshwater Crustacea from Sweden. (International Fisheries Exhibition, London, 1883. Sweden Special Catalogue, p. 140.) 121. De under Svenska vetenskapliga expeditionen till Spetsbergen, 1872-3, derstades samlade Hafs-Entomostraceen. (Kongl. Vetenskaps.-Akad Férhandl, XXXIL, No. IV., p. 3, 1874.) Linne, C. 122. Systema nature, VII vyd., 1748. Lubbock, J. 123. On the Freshwater Entomostraca of South America. (Trans. Entom. Soc, _ Vol. III, N. S., pt. IV, 1855.) 124. Onsome Entomostraca collected by Dr. Sutherland in the Atlantic Ocean. (Trans. Entom. Soc., Vol. IV, N. S., 1856, pt. IT.) 125. On some Oceanic Entomostraca collected by Capt. Toynbee. (Trans. Lin. Soc., Vol. XXIII, 1862, p. 173.) McIntosh, W. C. 126. Pelagic fauna of the bay of St. Andrews during the months of 1888. (7th Ann. Rep. Fish. Board of Scotland, pp. 259-310, T. 3-6.) Malcomson, S. M. 127. Recent Ostracoda of Belfast Lough. (Proc. Belfast Nat. Field Club, 1884-5, p. 259.) ENTOMOSTRACA OF MINNESOTA. 287 Martens, Ed. 128. Ueber einige beim Finkenkrug gesammelte Siisswassercrustaceen. (Sitz- ungsberichte Ges. Nat. Fr. Berlin, 1881.) May, Konv. 129. Ueber das Geruchsvermégen der Krebse nebst einer Hypothese iiber die analytische Thatigkeit der Riechharchen. Mit1 Taf. (Kiel, 1887.) Marsson, Th. 130. Die Cirripedien u. Ostracoden der weissen Schreibkreide der Insel Riigen+ Mit 3 Taf. (Mittheil. naturwiss. Ver. von New. Vorpominern, 12 Jahrg., 1881, pp. 1-50.) Metschinkoff. 181. Arb. erst. Vers. russ. Naturf. Abth. d. Anat. und Physiologie, 1868, p. 56. Milne, Edwards. 132. Histoire naturelle des Crustacés. Tome III, p. 409, pl. 36, 1840. Mobius, K. 133. Systematische Darstellung der Thiere des Plankton, gewonnen in der west- lichen Ostsee und auf einer Fahrt von Kiel in dem Atlantischen Ocean bis jenseit der Hebriden. (5 Ber. Komm. Unters. d. Meere, Kiel 12-16. Jahrg. 1887, pp. 109-124, T. 7, 8.) Moniez, R. 134. List des Copépodes, Ostracodes, Cladocéres et quelques autres Crustacés recueilles a Lille en 1886. (Bull. Soc. Zool. de France, XII, 1887.) 135. Notes sur des Ostracodes, Cladoceres et Hydrachnides observés en Norman- die. (Bull. Soc. d’Etudes Scient. de Paris, 1887.) 136. Faune des eaux souterraines de department du Nord et en particulier de la ville de Lille. (Revue Biol. Nord France, Lille, 1 Année, Crustacea, pp. 175-182, 241-257.) 137. Sur la faune de Hable d’Ault. (Revue Biol. Nord France, Lille, 1st Année, pp. 277-280, 346-350.) 138. Les males chez des Ostracodes d’eau douce. (Compt. rend. Ac. Sc., Paris, T. 112, No. 13, pp. 669-672, and abs. in Journ. R. Micro. Soc., London, 1891, P. 3, p. 346.) 139. Faune des lacs salés d’Algérie. (Mémoire Soc. Zool. France, T. 4, P. 3-4, pp. 246-257.) 140. Les males chez les Ostracodes d’eau douce. (Revue Biol. Nord. France, 3 Ann., No. 9, 1893, pp. 354-356.) 141. Description d’une nouvelle espéce de Cypris vivant dans les eaux thermales du Hamman-Meshkontine, 7 figs. (Bull. Soc. Zool. France, T. 18, No. 3, 1893, pp. 141-142.) 142. Quelques Cladocéres et sur un Ostracode nouveaux du Lac Titicaca. Avec 13 figs. (Revue Biol. Nord. France, 1 Ann., No. 11, 1893, pp. 419-429.) 148. Sur la présence en Asie du Cypris Madarazi, Orley. (Revue Biol. Nord. France, 4 Ann., 1893, No. 2, p. 80.) Marzek, Al. ie =! 144. Ocysticerkoidech nasich korysu sladknovodnich. (Véstnik krAl. Ceské spolecnosti nauk., 1890, Tab. V and VI.) 288 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. Muller, Fritz. 145. Bemerkung tiber Cypridina. (Jenaische Zeits., V., Heft 2, 1870, p. 255.) 146. Descripcao do Elpidium bromeliarum, crostaceo da familia dos Cytherideos. (Archiv. d. Mus. Nacional. Rio de Janeiro, LV, 1879, p. 27.) Muller, 0. F. 147. Fauna insectorum Fridricsdalina, 1764. 148. Zoologie Danicze Prodromus, 1776. 149. Entomostraca, 1785. Muller, G. W. 150. Die Spermatogenese der Ostracoden. (Zool. Jahrbiich. Herausgeg. v. Spen- gel, III. Bd., 1889. Pp. 677-726; 2 pl.) 15]. Ueber Lebenweise und Entwicklungsgeschichte der Ostracoden. (Math. w. Nat. Berlin Akad., 1893, Heft V, pp. 239-266.) Muller, Wm. 152. Zur naheren Kenntniss der Cytheriden. (Archiv. fiir Naturgesch., 1884, p. 1.) 153. Beitrag zur Kenntniss der Fortpflanzung und der Geschlechtsverhdltnisse der Ostracoden. (Zeitsch. f. d. gesamm. Naturwiss., 1880, p. 21.) 154. Ueber die Function der Antennendriise der Cytheriden. (Zeitsch. f. gesamm. Naturwiss., 1880, p. 213.) Nordquist, Osc. 155. Beitrag zur Kenntniss der inneren mdannlichen Geschlectsorgane der Cypriden. 156. Die pelagische und Tiefsee-Fauna der grosseren finnischen Seen. (Z. An- zeiger, 10. Jahrg., 1887, pp. 339-345, 358-362.) Norman, A. M. 157. Contributions to British Carcinology. (Ann. and Mag. Nat. Hist., Ser. III, Vol. VIII, 1861.) 158. Species of Ostracoda new to Britain. (Ann. and Mag. Nat. Hist., Ser. III, Vol. IX, 1862.) 159. Reports Deep-Sea Dredging, Coast of Northumberland and Durham. Crus- tacea. (Nat. Hist. Trans. Northumberland and Durham, Vol. I, 1865.) 160. Report of Committee for Exploring the Coasts of the Hebrides. (British Ass. Report, 1866, p. 198.) 16]. Last Report of Dredging among the Shetland Isles. (Brit. Ass. Report 1868, p. 248.) 162. Report Valorous Expedition. (Proc. Roy. Soc., No. 173, 1876, p. 202.) 163. Notes on the Marine Crustacea Ostracoda of Norway. (Ann. Nat. Hist., (7) Vol. 7, pp. 108-121.) Orley, S. ; 164. Ueber die Entomostraken—Fauna von Budapest. (Természetrajzi Fizetek X, 1886, pp. 7 and 98.) Pavesi, P. 165. Della mie annotorioni zoologiche. IV. Prime linee di uno studio zoologico delle nostre acque minerali. (Renconditi R. Instituto Lombardo, Vol. 14 1882, pp. 7-11.) 166. Altra serie di ricerche e studi sulla fauna pelagica di Jaghi italiani. (Atti. Soc. Veneto-Trent, Padova, Vol. 8, 1883, pp. 340-403, T. 8-14.) Ri ee! Le ee ENTOMOSTRACA OF MINNESOTA. 289 Peach, B. N. 167. On some new Crustaceans ‘from Lower Carboniferous Rocks of Eskdale and Liddesdale. (Trans. Roy. Soc. Edinburgh, Vol. 30, 1882, pp. 73-91, T. 7-10.) Pelseneer, P. 168. Note sur la présence de caridina desmaresti dans les eaux de la Meuse, (Bull: Mus. H. N. Belg., Tome 4, 1886, pp. 211-222.) Plateau, F. 169. Recherches sur les Crustacés d’eau douce de Belgique. (Mem. Couronnés et Mem. des Savants Etrangers, XXXIV, 1868.) Poggenpol M. J. 170. List of the Copepoda, Cladocera and Ostracoda of the Environs of Moscow. Russian. (Translation in: Trans. Kansas Acad. of Science, Vol. VIII, 1883. ) Poppe, S. A. 17]. Notizen zur Fauna der Siisswasserbecken des nordwestlichen Deutschland mit besonderer Beriicksichtigung der Crustaceen. (Abh. Nat. Ver. Bre- men, 10. Bd., 1888, pp. 295-300. ) Ramdohr, K. A. 172. Beitrige zur Naturgeschichte einiger deutschen Monoculus-arten, Halle, 1805. 173. Ueber die Gattung Cypris Miill. und drei derselben gehOrige neue Arten. (Mag. d. Gesell. naturforsch. Freunde in Berlin, Jahrg. II, 1808, pp. 83- 93, Taf. III.) Rehberg, H. 174. Beitrige zur Naturgeschichte niederer Crustaceen [Cyclopiden und Cypri- den]. (Abhandlung herausg. vom naturw. Vereine zu Bremen. Bd. IX, 1884.) Reuss, A. E. 175. Die fossilen Entomostraceen des osterreichischen Tertiarbeckens. (Natur- wiss. Abhandlungen, III, 1847, p. 41.) Robertson, D. 176. Notes on the Ostracoda and Foraminifera of the Firth of Clyde. (Trans, Geol. Soc. Glascow, Vol. V, pt. I, p. 112, 1874.) 177. Notes on a Raised Beach at Cumbre. (Trans. Geol. Soc. Glasgow, 1875.) 178. Notes on Cypris levis and its habit of perforating the leaves of Victoria regia. (Proc. Nat. Soc., Glascow, Vol. II, 1875, p. 7.) 179. Post-tertiary Deposits by Tunnel at Arkleston near Paisley. (Trans. Geol, Soc., Glascow, 1876, p. 292.) 180. Garnoch Water Post-tertiary Deposits. (Trans. Geol. Soc., Glascow, 1876- p. 281.) 18]. Post-tertiary Deposit at Misk-Pit and Kilwinning. (Trans. Geol. Soc. Glascow, 1877, p. 297.) 182. Notes on the Fauna and Flora of West Scotland, p. 38, 1876. 183. Ostracoda of Scotland. (Append. to Pt. I of Proc. Nat. Hist. Soc., Glascow, IV, 1880.) 290 GEOL. AND NAT, HIST. SURVEY OF MINNESOTA. 184. Fauna of Scotland, with special reference to Clydesdale and the western dis- tricts; Fresh and Brackish Water Ostracoda. Glascow, 1880. 185. Post-tertiary Beds of Garvel Park, Greenock. (Trans. Geol. Soc., Glascow, 1883, p. 1.) Rochebrune, A. T. 186. Observations sur la Cypris fusca. (Act. Soc. Lin. de Bordeaux, XXIV, 1861, p. 77.) Saccardo, P. D. 187. Cenni Storico-naturali intorno agli animaletti Entomostracei, etc. Treviso, 1864. Sars, G. 0. 188. OmeniSommeren 1862 fortagen Zoologisk Reise. Christiania, 1863. 189. Oversigt of Norges marine Ostracoder, 1865. 190. Nye Dybvandscrustaceer fra Lofoten. (Vidensk-Selks. Forhand, 1869, p. 170.) 191. Underségelser over Christianiafjordens Dybvandsfauna, 1869. 192. Undersdégelser over Hardangerfjordens Fauna. I. Crustacea. (Vidensk- Selks. Forhand, 1871, p. 278.) 193. Den Norske Nordhavs-Expedition 1876-1878, Vol. 15, Crustacea II, 1886; 96 pp. = 194. Nye Bidrag til Kundskaben om Middelhavets Invertebratfauna. IV, Ostra- coda Mediterranea. (Archiv. f. Math. og Naturvidenskab, 1887.) 195. On some Freshwater Ostracoda and Copepoda raised from dried Australian mud. (Christiania Vid. Selsk. forh. f. 1889, No. 8, 79 pp., 8 Taf.) Sars, Michael. 196. Om dei Nordge forekommende fossile dyrelivningen fra Quartzrperioden. Christiana, 1865. Schneider, Rob. 197. Ueber Eisenresorption in thierischen Organen und Geweben. (Abh. Akad. Berlin, 1888, 66 pp., 3 Taf.) Schnur. 198. Systematische Aufzihlung der Crustaceen, Arachniden und Myriopoden in der Umgebung von Trier. (Ges. f. niitzliche Forschungen zu Trier, 1856.) Schwarz, 0. G. 199. Ueber die sogenannte Schleimdriise der maunlichen Cypriden. (Berichten der Natur. f. Gesells. zu Freiburg, Bd. III, 1888, p. 5.) Seguenza, G. 200. Le Formazioni Terziarie nella provincia di Reggio (Calabria), 1880. 201. II Quaternario di Rizzolo. II. Gli. Ostracodi. (II. Naturalista Siciliano, Anno III, 1883.) Sostaric, Dragutin. 202. Prilog poznavanju faune slatknovodnih korepnjaka hrvatske. (Prést. iz XCII, knjige Rada jugoslavenske akademije znanosti i umijetnosti, W. Zagrebu, 1888.) Speyer, 0. 203. Die Ostracoden der Casseler Tertiarbildungen. Cassel., 1863. —_ q 3 | } ENTOMOSTRACA OF MINNESOTA. 291 Stimpson, W. 204. Synopsis of the Marine invertebrata of Grand Manan. (Smithsonian Con- tributions, 1853.) Straus, H. E. 205. Mémoire sur les Cypris. (Mém. du Museum, Vol. VII, 1821.) Stuhlman, F. 206. Beitrage sur anatomie der inneren minnlichen Geschlectsorgane und Sper- matogenese der Cypriden. (Zeits. f. wiss. Zool., XLIV, 1887, p. 536; and Zoologischen Institut. zu Freiburg, I. B , 1886.) Terquem, M. 0. 207. Les Foraminiféres et les Entomostracés-Ostracodes du Pliocéne supérieur de V’lle de Rhodes. (Mém de la Soc. Géol. de France, Sér. III, Vol. I, 1878.) Terrigi. . 208. Sulla fauna microscopica del caleare zancleano di Palo. (Atti. R. Accad. Lincei-Transunti, Vol. 6, 1882, pp. 253-256.) Thompson, G. M. 209. New Zealand Entomostraca. (Trans. New Zealand Institute, Vol. XI, 1878.) Toth, Alex. 210. Die in neuester Zeit zu Pest-Ofen gefundenen Schalenkrebse und ihre anat- omischen Verhdltnisse. (Verhdlgn. d. Zool.-bot. Gesell. Wien, XIII, 1863, p. 47.) Treviranus (both). 211. Abhandlung iiber den inneren Bau der ungefliigelten Insecten. (Vermischte Schriften anatomischen und physioloischen Inhalts, 1816.) Turner, C. H. 212. Notes on the Cladocera, Copepoda, Ostracoda and Rotifera of Cincinnati, with des. of new sp. (Bull. Sci. Lab. of Denison Uniy., Vol. VI, pt. II, 1€92, pp. 57-74; pl. L-IL.) 213. Additional Notes on the Cladocera and Ostracoda of Cincinnati, Ohio. I Systematic Part, with des. of new species. II Late Larval History of Cypris herricki. (Bull. Sci. Lab. Denison Univ., Vol. VIII, Part 1, 1893, pp. 1-18, pl. I-II.) 214. Preliminary Note on the Nervous System of the Genus Cypris. (Jour. of Comp. Neurology, Vol. III, 1893, pp. 35-40; pl. III and IV.) 215. Notes on American Ostracoda, with Description of new species. (Bull. Sci. Lab. Den. Univ., 1894, Vol. VIII, Part II, pp. 13-25, pl. VII and VIII.) 216. List of Known American Ostracoda, with description of new species. (Amer. Naturalist, 1894. [?]) 217. Ulrich. v. La Valette St. George. 218. Ueber die Genese der Samenkérper. Dritte Mittheilung. (Arch. fiir mikroskop. Anatomie. Bd. X, 1874, p. 497.) Vavra, V. 219. Uber das Vorkommen einer Siisswasser-Cytheride in BOhmen. (Zool. Anz., XIV, Jahrg. No. 357, 1891, p. 77.) 19 My SE eg ee _ Se 292 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. 220. Kritisches Verzeichnis der Ostracoden BoOhmens. (Sitzgsber. Kgl. bohm. Ges. d. Wiss., 1891, pp. 159-168. ) Vavra, Wenzel. 221. Monographie der Ostracoden BOhmens. (Prag, 1891.) Vernet, H. 222. Acanthopus, un nouveau genre d’Ostracodes. (Forel, Matériaux pour servir a l’étude de la Faune profonde du Lac Leman, IV® Série, 1879, p. 408.) Vejdovsky, F. 223. O. povodu fauny studniené. Slavnostni predndska ve vyrocnim sezeni kr4l. (Ceské spol. nauk v Praze dne 3. Cervna 1880.) 224. Thierische Organismen der Brunnenwiasser v. Prag. Mit 8 Taf. 1882. Wagner, R. 225. Beitrage zur Kenntness der Samenfliissigkeit der Thiere. (Arch. f. Naturg. von Wiegmann (Troschel). II Jahrg., 1836, 1 B., p. 369.) Weismann, A. 226. Parthenogenese b. d. Ostracoden. (Zool. Anz., Vol. III, 1880, p. 82.) Weismann, A., and Ischikava, C. 227. Ueber die Bildung der RichtungskOrper bei thierischen Eiern. 4 Taf. (Be- richte der Naturforsch. Ges. zu Freiburg, Bd. III, 1887.) Wierzejski, A. 228. Materialen zur Kenntniss der Fauna der Tatraseen. (Ber. physiograph. comm. Acad. Krakau, 1882, 16 Bd., pp. 1-24 (Polish).) Woodward, H. 229. A Catalogue of the British Fossil Crustacea. British Museum, 1887. Zacharias, 0. 230. Die Thierwelt der Eifelmaare. (Biol. Centralbl., 8 Bd., 1888, p. 574.) 231. Zur Kenntniss der Fauna des Siissen und Salzigen Sees bei Halle a's. (Zeit. f. wiss. Zool., 46 Bd., 1888, pp. 217-232.) - 232. Bericht iiber eine zoologische Excursion an die Kraterseen der Eifel. (Biol. Centralblatt, 9 Bd., 1889, pp. 56-64, 76-80, 107-113.) 233. Faunistische Untersuchungen in den Maaren der Eifel. (Zool. Anz., 11 Jahrg., 1888, pp. 705-706.) Zaddach, E. G. 234. Synopseos Crustaceorum Prussicorum Prodromus, 1844. Zenker, W. 235. De natura sexuali generis Cypridis. (Dissert. inaug. Berolini. c. tab. 1, 1850. ) 236. Ueber die Geschlectsverhaltnisse der Gattung Cypris. (Archiv. fiir Anatomie u. Physiologie. Herausg. von Dr. J. Miiller, pp. 193-202, Taf. V, 1850.) 237. Anatomisch-systematische Studien iiber die Krebsthiere. Berlin, 1854. 238. Monographie der Ostracoden. (Weigmann’s Archiv. f. Naturg., Tome XX, I. Bd., 1854, pp. 1-87, Taf. I-VI.) INTRODUCTION. The Ostracoda form a well-defined division of the Entomostraca. Like the Lamellibranchiata the body is always enclosed in a bivalve shell, which is closed by powerful abductor muscles. No doubt the casual observer often mistakes the Ostracoda for miniature mollusks. Yet the resemblance is all on the surface; for, although the structure of the enclosed Ostracodan is quite primitive, yet it is decidedly crus- tacean. The body always bears seven pairs of articulated appendages. The first five of these belong to the head; but, in different groups, either or all of the last three of these cephalic appendages may be modified for walking. The last two pairs of members belong to the body and are properly called legs or feet. In some cases, however, (Cypris) the last pair of legs is never used for locomotion. In most cases the abdomen bears a pair of appendages, which usually resemble one-jointed legs. Morphologically they probably are legs which have been arrested in their development. It is thought that a brief resume of the steps by which the Ostra- codes have been assigned to their present taxonomic position may be of interest. Linneus (or Linné) included all of the lower Crustacea in his genus Monoculus. : O. F. Muller divided the lower Crustacea into several genera. Col- lectively they were called the ‘‘Entomostraca.’’ Latreille and Cuvier were thé first to separate the Crustacea from the Insecta. Basing their judgment upon the morphology of the mouth parts, they divided the lower Crustacea into two artificial groups, the Branchiopoda and the Poecilopoda. The first division included the Phyllopoda and Lophyropoda, while the Ostracoda fell into the second division. Following in the footsteps of Latreille, Milne-Edwards, with the mouth parts for criteria, established an artificial system of classifica- tion for the Crustacea. Separating the Copepoda and Ostracoda from Latreille’s Branchiopoda, he united them in the group Entomostraca. Dana modified slightly Latreille’s system. The first attempt to form a natural system of classification for the lower Crustacea was made by Zenker. He separated the Copepoda 294 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. from the Ostracoda and used the name Entomostraca as a group name for the Siphonostoma and Lernaeoda. Claus used the word Entomostraca in a different sense. The Phyl- lopoda, Ostracoda, Copepoda and Cirripedia were collectively called the Entomostraca. Professor G. O. Sars has divided the Ostracoda into the following four sections: 1. Podocopa, 2. Myodocopa, 3. Cladocopa, 4. Platycopa. All of the members of sections 2, 3 and 4 and a portion of those belong- ing to section 1 are marine. Brady and Norman have divided the Podocopa into the following families: Family I.—Cypridide. Family I1.—Bairdiide. Family I11.—Darwinulide. Family I[V.—Cytheride. Family V.—Paradoxostomatide. This article treats exclusively of the first and third families. FAMILY CYPRIDIDE. “Shell generally thin and horny; valves equal or but slightly une- qual in size, surface usually smooth, or simply punctated; ventral margins more or less sinuated; hinge margins edentulous. Eyes sim- ple, usually confluent, sometimes wanting. Antennules (first anten- ne) slender, usually seven-jointed, very flexible, usually provided with a number of long hairs forming a dense brush. Antenne (sec- ond antenne) pediform, geniculated, four- or five-jointed, clawed at the apex, second joint mostly bearing an apical brush of hairs. Man- dibles strong, apex strongly toothed, palp four-jointed, with a setifer- ous branchial plate at the base. Two pairs of maxille, the first pair four-digitate; its external branch distinctly two jointed, bearing a large setiferous branchial plate; second pair small, composed of a single prehensile lobe and palp, which in the female is generally sim- ple, rarely pediform, is in the male prehensile. Two pairs of feet dis- similar in structure, the anterior pair strong, ambulatory, directed downwards, and having a long curved apical claw; posterior bent backwards within the shell, and not used for motion. Caudal rami usually well developed, elongated, very mobile, and bearing two or three apical claws. Intestine forming two dilations, of which the an- terior is provided with cecal appendages. Generative organs large, and of complex structure, and partly extended within the valves; in the male frequently a whorled sac connected with the testis; copula- ENTOMOSTRACA OF MINNESOTA. 295 tory organs symmetrica!, and of moderate size.’’ (Brady and Norman. ) It is thought that the following modification of Wenzel Vavra’s key will serve to differentiate the genera. KEY TO THE FAMILY CYPRIDIDE. I, The second foot terminates with a cylindrical joint that bears two backwardly directed sete. A. The second foot of the female and the male six-jointed. No branchial plate attached to the second maxille. Notodromas, 295 B. The second foot of the female five-jointed and of the male six-jointed. The second maxilla bears a branchial plate. a. The branchial plate is feebly developed in the form of two pectinated bristles. * The eyeisdeveloped. . ; ; 2 ; Candona, 298 ** The eye is absent. ; : : *Typhlocypris. 6. The branchial plate is joven in the form of three pec- tinated bristles. . ‘ 5 . *Candonopsis. e. The branchial plate is in the con of six acetate bristles. * The palp of the second maxillaisrudimentary. . *Ilyocypris. ** The palp of the second maxilla is normally developed. 7 The terminal joint of the second foot is as long as one-third of the fourth joint. : . : Cypria, 304 tj The terminal joint of the second foot is as long as two-thirds of the fourth joint. . , Cyclocypris, 310 II. The second foot terminates in a beak-shaped joint that bears one backwardly directed claw. A. Caudal rami are rudimentary. ¢ : : Cypridopsis, 312 B. Caudal rami are cylindrical with two eine claws. * Natatory set of the antenne short. 7 These setze not reaching to the tips of the terminal claws. Erpetocypris, 315 ++ These sete not reaching to the base of the terminal claws. *Scottia. ** Natatory sete of the antennz long, reaching to or beyond the tips of the terminal claws. + Parthenogenetic. . : : é : ; ‘ Cypris, 319 Tt Sexual. : : : 5 : ; : Cyprinotus, 329 (*Not noticed in the text.) In the above table an attempt has been made to tabulate all known freshwater genera of the Cypridide. The genus Stenocypris Sars has been omitted because the data at my disposal do not seem to warrant its separation from the genus Erpetocypris Brady and Norman. Of the twelve genera here mentioned, nine have been found in America. . GENUS NOTODROMAS Lilljeborg. 1853. f In shape the shell of the male is quite different from that of the female. The antennules are seven jointed. 296 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. In both males and females the antenne are six-jointed. The nata- tory sets extend to beyond the tips of the terminal claws. There is no branchial plate on the second maxilla. The palp of this jaw is two-jointed. In the female the distal joint is short and cylindrical, bearing at its apex two short sete; in the male the distal joint forms a long scythe-shaped appendage. The second foot is five jointed, terminating in three sete, two of which are directed backwards. The two eyes are not confluent. The abdominal rami are long and slender. Males are numerous. The cylindrical core of Zenker’s organ (verticillate sac) is ornamented with numerous closely set whorls of short stout spines. Notodromas monacha (0. F. Miiller). PLATE LXXII, Fia. 4-42. 1785.—Cypris monacha O. F. Miller (149), p. 60, Taf. V, Figs 6-8. 1820.—Monoculus monachus, Jurine (98), p. 173, Pl. XVIII, Figs. 13-14. 1837.—Cypris variabilis Koch (102), H. 10, 3. 1837.— ‘‘ lencomela Koch (102), H. 10, 4. 1837.— ‘‘ monacha Koch (102), H. 11, 1. 1837.— ‘‘ bimuricata Koch (102), H. 11, 2. 1837.— ‘‘ nubilosa Koch (102), H. 12, 4. 1814.— ‘* monacha Zaddach (234), p. 31. 1850.— ‘‘ monacha Baird (2), p. 153; Pl. IV, Figs. 1-11. 1851.— ‘‘ monacha Fischer (64), p. 146. 1853.—Notodroma monachus Lilljeborg (118), p. 95; Taf. VIII, Figs. 1-25; Taf. XII, Figs. 1:3; Taf. XXV, Fig. 16. 1854.—Cyprois monacha Zenker (238), p. 80; Pl. III, C. 1868.— ‘‘ monacha Plateau (169), p. 60; Pl. I, Figs. 22-23. 1868.—Notodromas monachus Brady (18), p. 379; Pl. XXIII, Figs. 1-9; PI. XXXVII, Fig. 3. 1870.—Notodromas monachus Heller (81), p. 78. 1872.—Cypris monacha Fric (69), p. 228. 1880.—Notodromas monachus Robertson (184), p. 22. 1882.— i monachus Herrick (85), p. 252. 1885.— i monachus Nordquist (155), Pls. I, II and IV. 1837.— ‘ monachus Korschagen (104), p. 24. 1888.—Cypréis monacha Schwarz (199), p. 11. 1889.—Notodromas monacha Brady & Norman (31), p. 96. 1891.— <2 monacha Wenzel Vavra (221), pp. 32-39; Figs. 7.9. This species does not seem to be as abundant in America as in Europe. I have never encountered it. The figures that accompany this description are Professor Herrick’s (86), and the following diag- nosis is due to Professor Brady (18): ; ‘““MaLE.—Carapace obliquely sub-quadrangular, greatest height equal to two thirds of the length, situated in the middle. Anterior ———— a ENTOMOSTRACA OF MINNESOTA. 297 margin broad, rounded at the angles, and expanded into a flattened lamina or flange. Ventral margin straight for about two-thirds of its length, then bending upwards at an obtuse angle. Dorsal margin arched, almost angular in the middle, whence it slopes steeply to the anterior border and with a bold curve towards the posterior extremity, joining the ventral margin at an acute angle. Seen from above, the carapace is ovate, pointed in front, and rounded behind; the greatest breadth in the middle. The ventral surface is bounded by two con- Spicuous, elevated, arcuate ridges, one at each valve, which together enclose a flattened lozenge-shaped area. Parallel to the contact margin of each valve runs another straight but much less conspicuous ridge, which towards the front curves outward, and joins the external ridge at an acute angle, the union of the two forming a slight eleva- tion, from which a single ridge runs forward, gradually merging in the flattened encircling flange of the anterior border. Seen from the front, the shell is sub-triangular, the sides convex, but flattened, the dorsum forming a flattened arch; the ventral border perfectly flat, and bounded by the projections of the outermost ventral ridges; the inner ridges form also conspicuous projections, which run obliquely upwards and inwards towards the flattened anterior flange. Lucid spots, about six, oblong and irregularly placed, their long diameters pointing transversely across the valve. Surface of the shell smooth and shining, marked by fine impressed lines forming a pattern simi- lar to the imbrications of fish-scales. Color pale greenish or white, transparent, with large and irregularly spread patckes of deep olive- green or black. ‘*PEMALE.—Sub-quadrangular. Anterior border flattened, flanged, forming with the ventral margin a well-marked angle; rounded above. Dorsal margin boldly arched, highest at the posterior third, whence it sweeps round with a deep curve to the postero-ventral angle. Ventral margin straight, slightly rising behind, and terminating in a flattened squamous plate, which projects backwards, with the appear- ance of aspine. The other aspects are similar to those of the male shell, except that the ventral surface of the left valve has at the pos- terior extremity of its contact margin a flattened squamous plate, which is received into a corresponding depression of the opposite valve.”’ Professor Brady (18) states that the branchial plate of the mandib- ular palp arises from the lower side of the palp, thus differing con. siderably from other Cypridide. Professor Vavra (221), however, says that the branchial plate arises from the upper side of the mandibular palp. ‘“‘The first foot in both sexes terminates in three curved claws, the central one being the strongest and longest. * * * * * * * 298 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. “‘The ‘glandular mucosa’ [Zenker’s organ] consists of a central cylinder, closely beset with radiating filaments, arranged in 50 to 60 transverse rows, the whole organ being imbedded in a sort of glairy matrix. The two glands are connected each by an efferent duct with the ‘bursa copulatrix,’ an organ of very complicated structure, and con- sisting ofa much convoluted canal (2 vesicula seminalis), an intromittant organ or penis, and two hooked appendages. The whole organ is very dense in structure, consisting probably of chitin, deep brown in color, and, with the ‘glandule mucose,’ constitutes a very considerable por- tion of the male carapace. It should be noted that the ‘bursa copula- trix,’ as well as the testis,* is a double organ, one on each side of the median line. The two burse lie closely in apposition but are not in organic connection except at the upper margin, where they are held together by a ligamentous tissue. Length ,; in. (1.1 mm.), height 3; in. (0.78 mm.).’’ Habitat: Minnesota (Herrick 785), GENUS CANDONA Baird. 1850. This genus, which was founded by Professor Baird (5) has recently been more restricted by Mr. Wenzel Vavra (221). In this connection the genus is used in Vavra’s restricted sense. In the female the antenna is five-jointed. In the male, owing toa division of the fourth joint, the antenna is six-jointed. At the division between the fourth and fifth joints of the male antenna two character- istic olfactory hairs are situated. The distal extremity of the third joint is not supplied with a brush of natatory sete. The rudimentary branchial plate of the second maxilla is composed of two, unequal, pectinated sete, which are attached directly to the basal portion of the maxilla. In the female the palp of this maxilla is two-jointed, and terminates with three unequal pectinated bristles. In the male this palp, which is then unjointed, differs in shape from that of the female- The second foot, which may be either five or six-jointed, terminates with three sets; two unequally long, backwardly directed, sete and one forwardly directed seta. The strong post-abdomen (abdominal ramus) bears two terminal claws. The seta on the caudal border of the ramus is quite remote from the end. At the origin of this ramus the dorsum of the body terminates in a short seta. The eye is small. Males are common, larger than the females. Seven circles of chitinous spines are arranged around the central cylinder of Zenker’s organ. The copulative organ is not so complex as that of Notodromas. * Dr. Brady uses testis as a synonym for Zenker’s organ. It is now well known that this organ is not the testis. ; f ) Ps ee a ENTOMOSTRACA OF MINNESOTA. 299 The absence of natatory sete from the antenne prevents the mem- bers of this genus from swimming. They creep along the bottom and frequently burrow in the mud or sand. Candona fabzeformis (Fischer.) PLATES LXXYV, Fias. 10, 11; LX XVI, Fias. 6, 8. 1851.— Cypris fabeformis Fischer (64), p. 146; Pl. III, Fig. 6-16. 1853.—Candona fabxformis Lilljeborg (118), p. 207. 1870.— ‘* diaphana Brady and Robertson (33), Pl. V, Figs. 1-3. 1889.— ‘* fabxformis Brady and Norman (31), p. 103; Pl. IX, Figs. 1-4. 1891— ‘ fabxformis Wenzel Vavra (221), pp. 45-48; Figs. 6, 2; Figs. 12, 1-9; Fig. 13. Length 1.03 mm. Height 0.49 mm. Width 0.38 mm. The shell is more than twice as long as high and nearly three times as long as wide. The shell being pellucid, the color of the enclosed body shines through the lorica and gives it a greenish yellow tint. Viewed from the side the shell of the female is sub-reniform; great- est height situated behind the middle; obtusely and evenly rounded in front, obliquely rounded behind. Ventral margin sinuated. Viewed from above the shell is compressed, tapering equally and suddenly to the two pointed extremities; sides almost parallel. Near each extremity a process from the left valve overlaps the right. The projection near the caudal extremity is much more pronounced than the other. The antennz are stout; the smooth terminal claws are slightly eurved and are not quite as long as the combined lengths of the last three joints. Natatorysete are absent. For the arrangement of sete consult the figures. _ The second foot is six-jointed. The abdominal rami are strong. In the female they are curved. The terminal claws are stout, curved and pectinate; the shorter claw is a little more than three-fourths as long as the other. The longer claw is about half as long as the entire ramus. Habitat: The only specimens yet found in America were found in a small spring-fed water tank on Clark University campus, Atlanta, Georgia, Aug. 30, 1894. ae oe : Candona acuminata (Fischer. ) "A PLATE LXXI, Fie. 34. 1851.—Cypris acuminata S. Fischer (64), p. 148; Pl. IV, Figs. 12-16. oe 4864.— ‘ id Zenker (238), p. 74; Pl. II, D. 1889.— ‘‘ he Brady and Norman (31), p. 104; Pl. IX, Figs. 9-10; Pl. X, Figs. 5-6. 1894.— “ “ ©. H. Turner (215), p. 19; Pl. VIII, Fig. 34. 300 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. Length 1.25mm. Height 0.58 mm. Width 0.46 mm. The shell is smooth, white, and elongated. It is more than twice as long as high and about three times as wide. Viewed from the side, the shell is sub-reniform, highest in the middle. Viewed from above, the shell is sub elliptical with pointed extremi- ties. The widest portion is in the middle. One valve is a trifle longer than the other. The antenne are stout. The natatory sets are absent and the ter- minal is long and non-pectinated. The post-abdomen (Fig. 34) is curved and slender. The terminal claws are slender and pectinated. Habitat: San Antonio River, Texas. I have seen only three speci- mens of this species. They were collected for me by Mr. A. B. Whitby. Candona crogmani Turner. PLATES LXXI, Fias. 24-33; LX XXI, Fies. 4-5. Candona crogmaniana—C. H. Turner (215), p. 20; Pl. VIII, Figs. 24-33. Length of female 1.52 mm. Height 0.76mm. Width 0.58 mm. This form is about the size of the elongated variety of Candona can- dida. The two most obvious differences are: 1, the inequivalve shell with pointed extremities; 2, the second foot is six-jointed. The shell is very thin, so thin that the ova and spermatozoids are visible through it. It is glossy and is covered with short scattered hairs. These hairs are more numerous around the margins than else- where. In the living specimen the body shines through the pellucid shell and gives it a greenish yellow tint. Numerous Vorticellide are usually found attached to the lorica. Viewed from the side (Fig. 33), the female is sub-triangular, the caudal third being the highest portion. The caudal, dorsal and ceph- alic margins are convex. The ventral margin is slightly sinuate, be- ing concave in the middle. Viewed from above (Fig. 32), the shell is an elongated ellipse, pointed at both ends. One valve is longer than the other and over- laps it at each extremity. The antenna (Fig. 25) is five-pointed in the female. Near the proximal end of the lower margin of the first joint there is one elon- gated filament and one short, pectinated, dagger shaped filament. The terminal claws are slender, non-pectinated and long—longer than the combined lengths of the last three joints. The antenna of the male is six-jointed. ENTOMOSTRACA OF MINNESOTA. 301 The mandibular palp (Fig. 31) is five-jointed. The first joint is large and bears at the distal angle of its inner margin a short dagger- like seta (Fig. 31). The distal half of this seta is pectinate. The _ mandibular blade is stout. The spines of the first mandibular process of the first maxille are non-pectinated. The first foot (Fig. 29) is long and slender and is composed of five joints. The second joint is about as long as the next two joints. The third and fourth joints are of about the same length. The fifth joint is the smallest of all. It is conical and from its distally directed apex arises the terminal claw. The terminal claw is slender and long. It is longer than the combined lengths of the last three joints and the distal portion is flexuose. The fourth joint of the second foot (Fig. 30) is somewhat obscurely divided into two joints, so that the second foot appears, under a high power, to be composed of six joints. The foot terminates in two long flexuose filaments and one shorter filament. The post-abdomen (Fig. 28) is of medium size. The terminal claws are slender, pectinated and curved. The terminal claw is about half as long as the abdominal ramus. The adjacent claw is a little shorter than the terminal claw. The filament in the caudal margin is about one-third the length of the ramus from the distal extremity of the post-abdomen. Habitat: Atlanta, Georgia, December, 1893. Abundant in the shallow ponds near South River. The ponds in which these speci- mens were found dry up in warm weather. Candona Peircei sp. n. PLATE LXXX. Length 0.70 to 0.79 mm. Height 0.33 to 0.37 mm. Width 0.22 to 0.51 mm. The color of the shell is white tinged with yellow. The surface is highly polished and bears a few scattered hairs. The muscle impressions are sub central and the eye is not visible through the shell. The animal is about half as high as long, but is not quite so wide as high. Viewed from the side the shell is sub-reniform, the greatest width being a littie caudad of the middle. The two extremities are rounded and are of about the same width. The dorsal margin is feebly convex, in some specimens it is nearly flat. The ventral margin is somewhat sinuous, the middle being slightly concave. In some speci- mens this margin is almost straight. oy i , 302 GEOL. AND NAT, HIST. SURVEY OF MINNESOTA. Viewed from above, the shell is sub-elliptical with pointed extremi- ties. The cephalic extremity is more sharply pointed than the caudal. The sides are convex.. The hinge-line throughout the greater part of its course is straight, but near the cephalic extremity of the valve there is a slight sinuosity. Viewed from below the shell has the same general appearance as when viewed from above. The con- tact line is quite sinuous. The antenna of the female is five-jointed. Near the distal extremity of the inner margin of the second joint there is a long seta, which ex- tends about to the base of the fifth joint. Near the proximal extremity of the inner margin of the third joint there is the usual biarticulate olfactory hair. Near the proximal extremity of the outer margin of the same joint arises a long seta which extends almost to the base of the next joint. From the distal extremity of the inner margin of this joint there arise one long and one short seta. The long seta reaches way beyond the tip of the fifth joint, while the short one does not reach to the extremity of the fourth joint. From the middle of the inner margin of the fourth joint there arise one long and one short seta. The long seta extends to beyond the tip of the terminal joint while the other extends to a little beyond the base of the same joint. From the middle of the outer margin of the fourth joint there arises a short seta which extends to about the base of the next joint. The tip of the fourth joint bears two long and one short claw. The two long claws are stout and are longer than the combined lengths of the last two joints. The short claw is only about twice as long as the terminal joint. From the tip of the fifth joint there arise one long and one shorter claw. The shorter claw is about two-thirds as long as the other claw. The tip of this joint bears also a biarticulate sensory filament. The antenna of the male is six-jointed. In structure and append- ages the first three joints resemble the corresponding portion of the female antenna. From the distal extremity of the fourth joint arise two peculiar biarticulate sensory filaments which extend to beyond the tip of the terminal joint. From the distal extremity of the outer margin of this same joint arises a short seta which extends to about. the tip of the fifth joint. From the distal extremity of the fifth joint arise two long curved claws and one medium seta. The claws, which are of equal length, are longer than the combined lengths of the last three joints. The claws arise from the outer portion, while the seta. springs from the inner angle of the margin. The seta is about one- half as long as one of the claws. From the distal extremity of the sixth joint there arise one long terminal claw and one biarticulate sensory seta. The claw extends to the tips of the claws that spring from the fifth joint, but the seta extends less than half so far. eee ae a ae ae ee 3 ‘4 a bg + ENTOMOSTRACA OF MINNESOTA. 303 The palp of the mandible is stout, the terminal joint of the same is short. The blade of the female mandible is stouter than that of the male. The first maxilla bears a large leaf-like branchial appendage. The second maxilla of the female has the usual generic form, the palp being two-jointed and bearing at its tip three short set. In the male the palp of the second maxilla is peculiarly modified and the palp of one side is larger than the palp of the other. The first foot is of the usual type. The second foot, as is always the case in this genus, bears at its tip two long and one short sete. The post-abdomen of the female is quite stout and bears at its tip two strong claws. This appendage is strongly curved. One claw is only about two-thirds as long as the other. The post-abdomen of the male is straighter than that of the female, but its borders are more irregular. The terminal claws are slender and of about the same size. The verticillate sac of the male bears seven whorls of chitinous spines. Habitat: Fayette county, Georgia. These specimens were found in the weedy shallows of a large millpond near Fayetteville, June 21, 1894. Candona delawarensis Turner. PLATE LXXI, Fiaes. 35-40. 1894.—Candona delawarensis C. H. Turner (215), pp. 21-22; Pl. VIII, Figs. 35-40. Length 0.95 mm. Height 0.54 mm. Width 0.43 mm. The color of this form is greenish yellow variegated with blotches of brown. Viewed from the side (Fig. 39) the shell of the female is sub-reni- _ form, the greatest height being about two-thirds the length of the animal from the cephalic extremity of the shell. The cephalic, dorsal and caudal margins are convex. The ventral margin is undulating, concave in the middle. Viewed from above (Fig. 37) the shell is an elongate ellipse with its greatest width in the middle. The extremities are pointed. The hinge-line is sinuous. Near the cephalic extremity there is a very pronounced sinuosity. Viewed from below (Fig. 38) the general outline is the same as when a. from above. The contact line is more sinuous than the hinge- ine. Viewed from the end the shell is elliptical. It is widest in the middle and the extremities are rounded. 304 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. The antenne bear no natatory sete on the antepenultimate joint. The terminal claws are non-pectinated and long. They are about as long as the combined lengths of the last three joints. The lower margin of the antepenultimate joint bears a modified sensory seta. The antenna of the male is six-jointed. The mandibular palp of the female is large. The antepenultimate joint bears, in addition to the usual long sensory sete, one short and stout sensory seta which is sub-rectangular in form with truncated ends and convex sides. It is about four times as long as wide. The spines on the first mandibular process of the first maxilla are not toothed. The post-abdomen of the male (Fig. 36) is slender and sub-triangu- lar. The terminal claws are slender and curved. Habitat: Jones’ Creek, Kent County, Delaware. The specimens that I have were collected by Mr. L. D. Hileland, March 3, 1894. GENUS CYPRIA Zenker. 1854. This genus, which was founded by Zenker (238), has been revised by Wenzel Vavra (221). Antennules are seven-jointed. Antenne in the female are five-jointed; in the male they are six- jointed. The distal extremity of the fourth joint bears two olfactory sete. The natatory sete on the third joint are very long, extending way beyond the tip of the terminal claws. The mandibular palp is much elongated; this is especially true of the terminal joint. The palp of the first maxilla is strongly developed. The second maxilla bears a well-developed branckial plate. In the female the palp of this member is unjointed and terminates with three setee. In the male the palp of the second maxilla forms a hooked pre. hensile organ. In that case the left palp differs somewhat in size and configuration from the right. The small terminal joint of the second foot, which is about one- third as long as the fourth joint, bears two equally long backwardly directed sete. The abdominal rami are robust; the caudal seta is situated about midway the caudal border. The eye is large. Muscle impressions four. Males are numerous. The central cylinder of Zenker’s organ is surrounded by seven whorls of chitinous sete. The upper part of the organ forms a blind dilated sac; the lower forms the funnel-shaped origin of the vas deferens. The copulative organ is triangular. The species of this genus are all small ovate or reniform creatures. ENTOMOSTRACA OF MINNESOTA. 305 Cypria exculpta S. Fischer. PLATES LXX, Figs. 1-8; LX XII, Fie. 3. 1853.—Cypris elegantula Lilljeborg (118), p. 206. 1854.— *‘ exculpta Fischer (65), p. 18; Pl. XIX, Figs. 36-38. 1854.— ‘* punctata Fischer (65), p. 77; Pl. III, Figs. 1-6. 1864.— ‘‘ striolata Brady (11), p. 60; PI. III, Figs. 12-17. 1868.— ‘‘ striolata Brady (18), p. 372; Pl. XXIV, Figs. 6-10. 1880.— ‘‘ granulata Robertson (184), p. 18. 1887.— ‘‘ striolata C. L. Herrick (86), p. 29; Pl. IV, Fig 3. 1889.—Cypria exculpia Brady and Norman (31), pp. 68-69; Pl. XI, Figs. 1-4. 1894.— ‘ exculpta C. H. Turner (215), p. 13; Pl. VII, Figs. 2-8. 1894.— ‘‘ exculptaC. H. Turner (216), p. —. Length of female 0.54 to 0.64 mm. Height 0.33 to 0.43 mm. Width 0.26 mm. . The shell is thin and somewhat transparent and is covered with a meshwork of sub longitudinal lines (Fig. 5). Viewed from the side (Fig. 3), the shell is orbicular, highest in the middle, the two extremities being of about equal height. The cepha- lic, dorsal and caudal margins are convex. The ventral margin is slightly sinuate, being concave in the middle. Viewed from above the shell is an elongated, laterally-compressed ellipse. The two extremities are of about the same width and the line of contact is straight. The natatory set of the antenne (Fig. 6) extend far beyond the terminal claws and are much longer than-the entire limb. The claws on the tip of each antenna are long and slender. They are longer than the last three joints. In the male the second maxille (Fig.8) are dissimilar. The tip of the second foot (Fig. 2) bears two short ectally project- ing set and two long setz which project backwards as far as the base of the antepenultimate joint. The post-abdomen (Fig. 7) is short, stout and curved. The ter- minal claw is strong and about half as long as the ramus. About the middle of the caudal margin of each abdominal ramus there is a short filamentous seta. Habitat: This species is quite abundant in shallow ponds and slowly flowing shallow creeks. In America this species has been found at: Atlanta, Georgia (Turner, 215); Burlington, Ohio (Turner, 215); Alabama (Herrick, 86); Kent County, Delaware (Turner, 215); Fayette County, Georgia (Turner). The specimens from Delaware were collected for me by Mr. L. D. Hileland. 306 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. Cypria opthalmica Jurine. % PLATES LXXV, Fies. 1-3, 7; LX XVI, Fias. 1-3, 5. } 1820.—Monoculus opthalmicus Jurine (98), p. 178; Pl. XTX, Figs. 16, 17. : 1835.—Cypris compressa Baird (I), p. 100; Pl. III, Fig. 16. 1837.— ‘' punetata Koch (102), H. 21, p. 23, Fig. 23. 1837.— ‘‘ tenera Koch (102), H. 12, p. 3. 1859.— ‘* compressa Baird (5), p. 164; Taf. XIX, Figs. 14, 14a-e. 1851.— ‘“ elegantula Fischer (63), p. 161; Pl. X, Figs. 12-14. ; 1853.— ‘‘ compressa Lilljeborg (118), p. 112; Pl. X, Figs. 16-18. 1854.—Cypria punctata Zenker (238), p. 77; Taf. III, A. 1868.—Cypris compressa Brady (18), p. 372; Pl. XXIV, Figs. 1-5; PJ. XXXVI, Fig. 6. B 1868.— ‘ ovum Fric u. Nekut (70), p. 48, Fig. 30. . 1872.— ‘* ovum Fric (69), p. 213, Fig. 28. 1875.— ‘‘ compressa Brady, Crosskey, and Robertson (30), p. 123; Pl. I, Figs. 5, 6. 1879.—? Cypria neglecta Herrick (88), p. 112; Pl. XVII, Fig. 2. 1885.— Cypris punctata Nordquist, (155) p. 150. 1888.— ‘* punctata Schwarz (199), p. 18. 1888.— ‘‘ compressa Sostaric (202), p. 47. 1839.—Cypria opthalmica Brady and Norman (31), p. 69; Pl. XI, Figs. 5-9. 1891.— ‘* opthalmica Wenzel VAvra (221), pp. 63-66; Figs. 19, 19!-19°, 20, 201-204. Length 0.55 to 0.58 mm. Height 0.37 to 0.40 mm. Width about 0.30 mm. The American representative appears to be somewhat wider than the European type. The translucent shell is covered with irregularly scattered large puncta. Near the two extremities, the shell bears long hairs. Viewed from the side the shell is reniform, widest back of the mid- dle. Near the two extremities, the dark puncta are often so clustered as to form dark blotches. Caudal, dorsal and cephalic margins con- vex. Ventral margin is somewhat sinuate. Viewed from above the shell is ovate, the cephalic end somewhat more narrow and more pointed than the caudal extremity. Hinge line is straight. Viewed from below the contact line is sinuate. Viewed from the end the shape is oval, much higher than wide. For the structure of the female antenna consult Fig. 1. For the structure of the mandible consult Fig. 5. For the structure of the second foot consult Fig. 2. For the structure of the abdominal ramus consult Fig. 3. Habitat: ? Minnesota (Herrick, 83); Baxley, Georgia. The speci- mens from Baxley were collected for me by Mr. A. B. Whitby. The figures were drawn from Baxley specimens. ENTOMOSTRACA OF MINNESOTA. 307 Cypria mons (Chambers). PLATE LXXXI, Fias. 6-12. ? .—Cypris mons Chambers (41), pp. 153-154, Fig. 3. 1887.— ‘* mons C. L. Herrick (86), p. 32. Length 0.70 mm. Height 0.45 mm. *“Ovoid; tumid; highest immediately before the middle. Length 3 inch; height +. Dorsal margin regularly arched, sloping more rapidly behind the highest point than before it. Extremities rounded; the anterior widest ventral margin very slightly sinuated. Seen from above, ovate, but less tumid than Cypridopsis vidua as figured by Baird and Brady (Brit. Ent. and Trans. Linn. Soc.). But little or not at all narrowed in front; widest a little behind the middle. Lucid spots seven, near the middle of the valve; the three lower ones in a line and small; one of them very small. Valves white, shining smooth, with numerous almost confluent puncta. The sete of the lower antenneze extend beyond the apex of the claws, and the articulate appendage of the third joint has its apex swollen or enlarged. Superior antennze with two long and one short seta from the end of the fourth joint; two from the end of the fifth joint; four long ones from the end of the sixth; two long and two short from the end of the seventh (there are also other short setz on the different joints). The last joint of the inferior antenne is small, almost rudimentary, bearing a single large claw. (Indeed, it seems to be bifid, with a claw from each branch.) There are three other claws articulated to the end of the penultimate joint, from which also arise four sete shorter than the claws; two moderately long sete arise from about the middle of the fourth joint above, and three longer ones below; the usual fascicle of five long and one short sete from the third joint, just behind which is a bunch of short cilia and another bunch on the under side. Abdominal ramus Straight, slender, with two claws, one under the other. The mandib- ular palpus, with branchial appendage and two large plumose and one simple sete from the end.’”’ (Chambers. ) I have never seen specimens of the above. It is certainly very closely related to Cypria opthalmica (Jurine), yet it seems to be dis- tinct. Habitat: Pond on Mount Elbert, Colorado; altitude 11,000 feet. (Chambers, 41.) Cypria inequivalva Turner. PLATE LXVIII, Fias. 1-8. 1893.— Cypria inequivalva C. H. Turner (213), pp. 6-8; Pl. I, Figs. 1-8. 1894.— ‘ inequivalva C. H. Turner (215), p. 14. 1894.— ‘“ inequivalva C. H. Turner (216). a 3) ¢ a 0 Fit > Length 0.46 mm. to 0.52 mm. Height 0.35 mm. to 0.36 mm. Width 0.26 mm. Shell inequivalve, one valve overlapping the otherin front. Valves glossy, finely pubescent. In fresh specimens, near the cephalic end of the shell, there is an irregular cross-shaped dorsal dark spot (Figs. 1, 2), the arms of which extend latero-ventrad along each valve for about one-half the height of the valve. Near the caudal extremity of the shell there is another irregular dorsal dark spot. This spot is somewhat fan-shaped, with the expanded portion directed caudad. Occasionally, on the ventral surface, about one-third the length of the valve from the cephalic ex- tremity, asmall dark spot is seen. In fresh specimens these markings are very pronounced; but in alcoholic specimens, they are usually more or less obscured. Viewed from the side (Fig. 1) the shell is sub-reniform, higher near the middle. It is about twice as long as high. Dorsal margin, feebly convex; cephalic margin, convex; ventral margin, nearly straight, slightly concave in the middle; Sek margin convex. Viewed from above (Fig. 2) the shell is sub-elliptical, inoue one valve overlapping the other in front. Shell widest near the mid- dle. Cephalic extremity about as wide as the caudal. All margins convex. Hinge-line straight. Viewed from below (Fig. 3) shell presents the same outline as when viewed from above, but the line of contact of the two valves is sinuated. Viewed from the end, the shell is oval, widest in the middle, ventral margin about as wide as dorsal. Antennules typical for the genus. Antenne of female (Fig. 4) composed of five joints, the joints diminishing in size from the second to the most distal joint. The second joint bearing at about the middle of its ental margin a long seta. The next joint bears at about the middle of its ental margin the usual biarticular sensory hair and at its disto-ental angle a moderately long plumose seta, this seta extends to about the base of the terminal claws. From the base of the penultimate joint arise five very long non-plumose sete, these sete extending far beyond the tips of the terminal claws. At the middle of its ental border this joint bears a short seta, and opposite this on the ectal border there is a slightly longer seta. From the disto-ental angle of this joint arise two short sete. From the ectal half of its distal margin arise two long claws; one of these claws extends beyond the tip of the claws springing from the terminal joint, while the other extends nearly to the tip of those claws. At the extremity of the terminal joint there are two large 308 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. ENTOMOSTRACA OF MINNESOTA. 309 claws and two short set; one of these sete is located at the disto-ental angle and the other at the disto-ectal angle of the joint. The claws are smooth. In the male the antenna is six-jointed, and the terminal claws are longer and more flexible than in the female. Mandible resembles that of Cypria exculpta Fischer. First foot of female (Fig. 5) long and slender, composed of five joints. The most proximal joint large, the broadest of all. The next joint the shortest of all. The antepenultimate joint about as long as the most proximal, but more slender. From the margin of this joint arise two short sete. From the disto-caudal angle of this joint arises a long seta which extends to beyond the base of the terminal claws. From near the disto-cephalic angle of this joint arises a short seta. Along the cephalic margin of the penultimate joint there is a longi- tudinal row of fine hairs. From the disto-caudal angle of this joint arises a seta of medium length. From the extremity of the terminal joint arises a long claw; this claw is much longer than the joint and appears to be composed of two portions; a short proximal and a long distal portion. From the cephalic margin of the proximal portion arises a Short seta. Second foot of female (Fig. 6) composed of five joints, the joints diminishing in size from the second to the most distal joint. The most proximal joint bears at about its proximo-caudal angle a long plumose seta which is as long as the joint; and from the distal third of its - cephalad margin arises a somewhat shorter seta. From the distal fourth of the cephalic margin of the antepenultimate jointarises a seta. From a corresponding point on the penultimate joint there also arises aseta. From the extremity of the terminal joint arise two long and two short sete. The two long sete are about as long as the entire limb. The two shorter set are but little longer than the terminal joint. Post-abdomen (Fig. 7) is curved, bearing one terminal claw and at its base a short terminal spine. On the convex surface there is a sub- terminal claw. Verticillate sac (Fig. &) of male as usual in this genus. It seems to be enclosed by a transparent capsule. Habitat: This species is abundant among the grass and weeds of many shallow ponds. It has been found at the following places: Cincinnati, Ohio (Turner, 213); Atlanta, Georgia (Turner, 215); Fay- ette County, Georgia (Turner, 216). 310 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. GENUS CYCLOCYPRIS Brady & Norman. 1889. This genus, founded by Brady and Norman (31), has been amended by Wenzel Vavra (221). Antennules are seven-jointed. The antenne of the female are five-jointed; of the male, six-jointed. There is no olfactory organ on the fourth joint. Natatory sete are very long, reaching far beyond the tip of the terminal claws. The palp of the mandible and of the first maxilla normally developed. The second maxilla bears a branchial plate and a palp. In the female this palp is unjointed; in the male it forms a hooked prehensile organ. ; The last joint of the second foot is unusually long, being two-thirds as long as the fourth joint. Males are numerous. Zenker’s organ is similar to that of Cypria. The proximal side of its central cylinder is flat. Vas deferens is long and convoluted. The copulative organ is quadrangular. The abdominal ramus is robust, the caudal seta is situated at about one-third the length of the caudal border of the ramus from its distal extremity. Cyclocypris levis (0. F. Miiller.) PLATE LXX, Fias. 9-11. 1785.—Cypris levis Miiller (149), p. 52; Pl. III, Figs. 7-9. 1820.—Monoculus ovum Jurine (98), p. 179; Pl. XIX, Figs. 18, 19. 1835.—Cypris minuta Baird (1), pp. 99; Pl. III, Fig. 9. 1837.— ‘‘ brunnea Koch (102), H. X., Fig. 5. 1837.— ‘‘ lepidula Koch (102), H. X. 6. 1850.— ‘‘ minuta Baird (5), p. 155; Pl. XVIII, Figs. 7 and 8. 1851.— ‘‘ pantherina Fischer (64), p. 163; Pl. XI, Figs. 6-8. 1853.— ‘* ovum Lilljeborg (118), p. 113; Pl. X, Figs. 18-15. 1868.— ‘‘ ovum Brady (18), p. 373; Pl. XXIV, Figs. 31-34, 43-45; Pl. XXXVI, Fig. 8. 1868.— ‘‘ ovum Claus (48), Pl. I, Figs. 1-5. 1874.— ‘‘ ovum Brady, Crosskey & Robertson, (30), p. 125; Pl. I, Figs. 29, 31. 1888.— ‘‘ ovum Schwarz (199), p. 18. 1888.— ‘‘ ovum Sostaric (202), p. 46. 1889.—Cypria levis Brady and Norman (31), p. 69. 4 1891.— ‘* levis Wenzel Vavra (221), pp. 68-71, Figs. 21, 21?-21°. 1894.— ‘‘ Jzvis C. H. Turner (215), pp. 14, 15; Pl. VII, Figs. 9-11. 1894.— ‘' levis C. H. Turner (216). Length 0.51 mm. to 0.57 mm. Width about 0.4 mm. The somewhat translucent shell is hispid and very tumid, being about as broad as it is high. Viewed from above the shell is ovate with rounded extremities. The eye, which is situated near the cephalic extremity of the animal, is easily seen through the shell. ENTOMOSTRACA OF MINNESOTA. 311 The five large setz on the antepenultimate joint of the antennze extend way beyond the tip of the terminal claws (Fig. 9). The distal extremity of each seta is plumose. According to Professor Brady* in Cypris ovum (Jurine) only two of the natatory setz of each antenna are long. In this respect Cypris ovum (Jurine) differs from the specimen under consideration; but since they are similar in all other features I consider them to be of the same species. The terminal joint of the mandibular palp is short. The terminal claws of this palp extend to the tip of the mandibular teeth. The slightly curved terminal claw of the first foot is slender and is about as long as the combined lengths of the three distal joints. The terminal joint of the second foot is about two-thirds as long as the fourth joint (Fig. 11). The long, slender, backwardly directed seta upon the distal extremity of this joint is longer than the combined lengths of the three distal joints. This joint bears at its apex two other set; one, about the same length as the joint is directed back- ward, the other is very short and is directed forward. The short post-abdomen is about twice as long as its terminal claws. The stout claws are feebly curved. Habitat: I have seen only three specimens of this species. These Professor L. D. Hileland collected in Jones’ Creek, Kent County, Dela- ware, March 31, 1894. Cyclocypris modesta (Herrick.) PLATE LXXII, Fies. 5, 5*, 5a, ETc. Cypris modesta C. L. Herrick (86), p. 28; Pl. IV, Fig. 5. This species has never been seen by me. Probably its nearest ally is Cypria inequivalva Turner. The figures as well as the text of this species are taken from Professor Herrick’s work (86). ‘Shell sub-reniform, greatest height behind the middle, upper out- line somewhat obliquely truncate, especially in the male; color yellow- ish, seareely maculate, nearly smooth. Antenne short, with long non-plumose filaments, two from the apical and four from the penulti- mate segment very long, others half as long; second antenne with three toothed claws on the penult segment, one together with three smaller ones, on the apical, antepenult segment armed only with small bristles, preceding one with six long sete exceeding the claws; first foot slender, apical segment long conical, with a long serrate claw and bristle, other sete short ; second foot (in male) with a short terminal Segment armed with two very long sete and one shorter one; caudal stylets very slender, with a terminal claw, a sub-terminal claw some- * Recent British Ostracoda, p. 373. 312 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. what smaller and a weak pectinate seta one-fifth the length of the stylet from the end; palp of mandible very bristly. The intromittant organ of the male is more simple than those hitherto described, con- sisting of a broad, flat basal segment on either side, with a coiled ductus ejaculatorius and a funnel-shaped terminal portion consisting of two opposable flaps. The basal segment is indistinetiy two jointed and those of both sides are seated on a common prominence. ‘*Length of male 1.70 mm., of female 2.16 mm.; height of male 0.84 mm., of female 1.24 mm. The above measurements are too large, but express the correct proportions. It is one of the smaller species.”’ Habitat: ? Alabama (Herrick, 86). GENUS CYPRIDOPSIS Brady. 1868. The antennule is seven-jointed. The antenna is five-jointed. The five natatory sete on the third joint are plumose, The branchia of the second maxilla consists either of a plate bear- ing five plumose sete or else of two setze which are inserted directly on the blade. The second foot is five-jointed and bears, near its extremity, a strong chitinous claw. The abdominal rami are rudimentary. The members of this species seem to be exclusively parthenogenetic. Cypridopsis vidua (0. F. Miller.) PLATES LXXII, Fias. 1-1lg; LX XV, Fies. 5, 6, 8,9; LX XVI, Fies. 4, 7. 1785.—Cypris vidua O. F. Miiller (149), p. 55; Taf. IV, Figs. 7-9. 1820.—Monoculus vidua Jurine (98), p. 175; Pl. XIX, Figs. 5-6. 1837.—Cypris maculata Koch (102), H. 10, 2. 1841.— ‘ strigata Koch (102), H. 36, 19. 1844.— ‘‘ vidua Zaddach (234), p. 35. 1850.— ‘‘ vidua Baird (5), p. 152; Pl. XIX, Figs. 10-11. 1850.— ‘‘ — sella Baird (5), p. 158; PL XIX, Figs. 5, 5a. 1851.— ‘‘ vidua Fischer (64), p. 162; Taf. XI, Figs. 1-2. 1853.— ‘* vidua Lilljeborg (118), p. 111. 1854.— ‘ vidua Zenker (238), p. 79. 1868.—Cypridopsis vidua Brady (18), p. 375; PJ. XXIV, Figs. 27-36, 46. 1868.—Cypris vidua Claus (48), Pl. I, Figs. 6-8. 1868.— ‘‘ vidua Fric and Nekut (70), p. 48, Fig. 29. 1869.— Cypridopsis obesa Brady and Robertson (32), p. 364; Pl. X VIII, Figs. 5-7. 1870.— . obesa Brady and Robertson (33), p. 15. 1870.—Cypris vidua Heller (81), p. 90. 1872.— ‘‘ vidua Fric (69), 227. 1874.—Cypridopsis obesa Brady, Crosskey and Robertson (30), p. 128; Pl. I, Figs. 1- oe 1879.—Cypris vidua C. L. Herrick (&3), p. 112; Pl. XVII, Fig. 1. ENTOMOSTRACA OF MINNESOTA. 313 br 5 - 1887.—Cypridopsis vidua C. L. Herrick (86), p. 33; Pl. IV, Fig. 1. «1888. — Cypris vidua Sostaric (202), p. 46. ; 1889.—Cypridopsis vidua Brady and Norman (31), p. 89. 1ei— “ vidua Wenzel VAvra (221), pp. 75-77; Figs. 23, 231-234. 1892.— = vidua C. H. Turner (212), p. 73. 1894.— = vidua C. H. Turner (215), p. 19. 1894.— ha vidua C. H. Turner (216). Length 0.54 mm. to0.7 mm. Height 0.34 mm. Width 0.37 mm. to 0.49 mm. The color of the tumid shell is yellowish green. The shell is cov- ered with short sparse hairs and is marked with three characteristic dark bands (Pl. LX XV, Figs. 5, 8). These bands are confined to the dorsal surface. Viewed from the side (P]. LX XV, Fig. 5) the shell is sub-reni- form in outline, widest in the middle. Excepting a slight concavity at the middle, the ventral margin is straight. The other margins are strongly convex. Muscle impressions sub central. Viewed from above (Pl. LX XV, Fig. 8) the shell is broadly orvid, being widest caudad of the middle. The two extremities are round- ed, but the cephalic extremity is much more narrow than the other. The sides are strongly convex and the hinge-line is straight. Viewed from below (Pl. LX XV, Fig. 6) the shell has the same general shape as when viewed fromabove. The contact line issinuous and there is a slight depression in the centre. Viewed from the cephalic end (P]. LXXV, Fig. 9) the shell is a broad oval, being wider than high. Contact line straight. The antenna is five-jointed (P]. LXXVI, Fig. 7). The terminal joint is small. A projection from the outer angle of the distal ex- tremity of the penultimate joint extends half way the length of the ter- minal joint. Two of the terminal claws are stout and one of them bears, on its inne margin, blunt teeth. The natatory sete extend toa little beyond the tip of the terminal claws and are plumose. The mandible is stout. The claws of the mandibular palp extend to the tips of the mandibular teeth. The antepenu!timate jointof the _ palp bears a short, pectinated, dagger-shaped seta. As far as my ob- servations go, the penultimate joint does not bearsuchaseta. The fact that the dagger-shaped seta found on the penultimate joint of some Cppride occurs on the side renders its detection quite difficult. The abdominal rami (Pl. LXXVI, Fig. 4) are rudimentary, the long slender terminal claw being longer than the ramus. In addition _ to the terminal claw there is a shorter and more slender claw. Habitat: This species occurs in all kind of fresh water. I have found it in small tanks, pools, ponds, lakes, creeks and small rivers. _ It usually occurs in great numbers. Pane Tee Ne 314 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. In America it has been found in the following localities: Eastern United States (Herrick, 86), Georgia (Turner, 215, 216), Ohio (Turner, 212, 213), Texas (Turner 215, 216), Minnesota (Herrick, 83), West Virginia (Turner, 215). The Texas specimens were collected by Mr. A. B. Whitby. Cypridopsis newtoni Brady and Robertson. ‘PLATE LXXII. Fic. 6-6h. 1870.—Cypridopsis (?) newtoni Brady and Robertson (33), p. 14, Pl. VII, Figs. 14-16. 1874.— a. newtoni Brady, Crosskey and Robertson (30), p. 129; Pl. II, Figs. 20-21. 1887.— a: hystrix C. L. Herrick (86), pp. 30, 31; Pl. IV, Fig. 6. 1889.— cs (?) newtoni Brady and Norman (31), pp. 90, 91; Pl. VIII, Figs. 16, 17. 1891.— Ms newtoni Wenzel Vavra (221), pp. 77-79; Figs. 24, 241-249. 1894.— é C. H. Turner (216). Not having met this species, I here give Professor Herrick’s de- scription. The figures are his also. ‘*Length equal to about twice the greatest height which lies just behind the anterior third, anterior outline much higher than the pos- terior, and evenly rounded, posterior margin acutely angular, lower Outline slightly concave, upper margin twice angled; shell covered with long curved spines; color yellowish, with eight lucid spots. An- tenn (first antenn) slender, composed of seven segments, of which all but the basal are short and sub-equal. * * * * * Antennules (second antenne) with very short apical segment with two strong un- equal claws and a minute seta, penultimate with two equal toothed claws and a number of slender set, third from end with five long and several short sete, preceding segment large, with three slender sete. First foot five-jointed, second joint elongated, third and fourth equal, each with a single short seta, apical segment small, with two sete and a long toothed gently curved claw; last foot moderately slender, termi- nal joint with a small claw and two setx at the apex and a lateral Spine. Caudal stylets reduced to minute papille bearing a slender claw and a flexuous spine. The mouth parts bear the characters of the genus Cypris. ‘‘In this species there is an aureole-like lucid zone about the an- terior of the shell and a similar, but triangular, appendage behind. ‘‘The species may be regarded as forming a transition to Cypris proper, as the form if not the size of the stylets is more as in that genus.”’ Habitat: Minnesota (Herrick, 86). y if a > te oe ¥ ml » a id x “4 - ENTOMOSTRACA OF MINNESOTA. 315 GENUS ERPETOCYPRIS Brady and Norman. 1889. *‘General characters of the animal closely approaching those of Cypris; but the setze of the third joint of the lower antennz 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, Fies. 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 #. fasciata the caudal margin of the abdominal ramus is smooth» but in ZF. minnesotensis it is pectinate. In H. fasciata the length is three times the width, but in EH. 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 four long Sets, antepenult segment with two long plumose set above, preceding segment with shorter sete; second antenne 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 set, 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). Ss Bi ~ 7 316 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. XXXVIILI. 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 [ Hrpetocypris] 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 sete forming a stout fascicle, which extends beyond the end of the antenna a distance equal to the length of the antenna itself. 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 sete, 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 sets, 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 sete, which diminish in length inward, most of them slightly plumose, and two long slender sets, 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- catory lobe, fringed with a soft silky pile. and bearing three more or less plumose sete 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 isshort and straight. The third segment is slightly longer than the second and about two-thirds as thick. The fourth segment is three- - Pea he ee 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 sete. The series of teeth with numerous accessory smaller teeth and spines, and 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 set 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. ‘*First 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 apicai 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. ‘‘Caudal 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 set, 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 sete 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, and 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. | pee Tae nn 320 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. Cypris fuseata Jurine. PLATES LXXI, Fies. 41-46; LX XII, Fies. 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. X XT, 19. 1844.— ‘‘ fuscata Zaddach (234), p. 32. 1850.— ‘‘ fusea 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.— ‘* fusea Brady (18), p. 362; Pl. XXIII, Figs. 10- 15. 1887.— ‘‘ dugesiC. L. Herrick (86), p. 26; Pl. IV, Fig. 7 1888.— ‘‘ fusea Sostaric (202), p. 47. 1889.— ‘* fuscata Brady and Norman (31), p. 73; Pl. XII, Figs. 3-4. 1891.— ‘‘ fuscata Wenzel Vavra (221), pp. 98-99, Figs. 33, 331-33%. 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 apne 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. Se ee ee ee ee oe oe 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.— ‘ tristriata 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 Fricand 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, Figs. 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, 36!-36¢. Only once have I encountered an American form which I supposed was Cypris 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 sinnated 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. Height1.72mm. 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 iength 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; antenne 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 set of moderate length below; antennules (antennz) slender, apical segment with two serrate claws and two slender sete, fourth (antepenult) segment the same, third segment with four long and two shorter setze, second segment with six long pectinate sets 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 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 C. 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 a little nearer to this species, but is too distinctly reniform. C. 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 antenn with only twelve instead of fourteen long set, arranged as follows: There are two short set (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 ©. virens, being only one-twentieth of an inch _longand one-fortieth high instead of one-fourteenth of an inch long and 21 324 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 pune- 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 distinet 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, Fias. 40-42; LXIX, Fries. 32-39. 1892.—Cypris Herricki C. H. Turner (212), pp. 71-73; Pl. I, Figs. 1-10. 1893.—Cypris Herricki C. H. Turner (213), pp. 11-15; Pl. I, Figs. 33-39; Pl. II) Figs. 40-42. Length 3.0 mm. Height 1.70 mm. 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 bloteh, 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 ecephalo-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 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 4 Square a short band passes dorso caudad and fuses with a broader band _ which passes caudad, approximately parallel to the dorsal margin of _ theshell. From this same corner another band passes caudo-ventrad _ almost to the caudal margin of the shell. This band is approximately Na 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 Xi ‘eurves dorsad, otherwise it is approximately parallel to the band last _ deseribed. 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 _ whieh 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 _ deseribed. ; yt Viewed from the ventral surface one valve overlaps the other in front. The contact line is sinuous, being laterally convex at the mid- die. Viewed from the end the shell is oval in shape, the greatest width being near the dorsal surface. —-- Antennee slender; the natatory set 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 _fivst maxilla are smooth. The extremity of that same process bears _- two setze as long as the biarticulate claws; one, which is curved and ¥ “smooth, is situated at the outer angle and ie 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. Be. The post-abdomen is long, slender and straight. The distal portion ts outer margin is pectinated. The terminal claws are curved and . . , L%" 326 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. an Habitat: Cincinnati, Ohio. Very abundant in a shallow canal basin in Camp Washington. Up to date it has not been found in any other locality. LATE LARVAL HISTORY OF CYPRIS HERRICKI. PLATES LXVIII, Fias. 40-42; LXIX, Fias. 33-39. In this connection it is not intended to discuss the early stages of Cypris 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. The earliest stage here discussed has been compared to the seventh stage of Cypria opthalmica Jurine, because in that stage the appendages have attained about their permanent form; but it must not be sup- posed that in this Cypris there are only two subsequent larval stages. These stages are tabulated in the following table: Stages.| Length. Height. Position of Dorsal Hump, Ete. Form of Post-abdomen. Rudimentary; fewer spines | i . A 0.90mm. | 0.57mm. | Some distance in front of middle. won ai nga iF ona Teeth on caudal margin of shell. than remainder-of the ap- pendage. Form normal; number of spines normal; ratio of the length of the post-abdomen greater than in adult, 1.32 mm 0.71 mm. | Approaching middle. t 1.38mm. | 0.84mm.,. | Teeth on shell much larger. Ratio of the length of ter- 1.98mm. | 1.20mm. | Near the middle. minal spine to the ler gth of Cc 1 post-abdomen more neurly | Teeth on shell large. | normal than in B. 2.79mm. 1.64mm, | At middle. About as in adult. ¥ | Teeth disappearing. : Adult. | 3.00mm. | At middle. “ No teeth on shell. MW : In Cypria opthalmica (Jurine) Claus found that by the time the : / seventh stage was reached, the shell had practically assumed its final — form. In the 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. ENTOMOSTRACA OF MINNESOTA. gar _ In the adult Cypris Herricki 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 _Himer. 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 Cypris 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 bap post abdomen appears before the formation of the sec- —— G. H. Th. Eimer. Organic Evolution as the R2sultof the Luoheritanze of Keaiired Characters , Mictedine to the Laws of Organic Growth. Translated by J. T. Cunningham, 1890. P. 7 328 GEOL. AND NAT, HIST. SURVEY OF MINNESOTA. ond pair of legs. In stage B the post-abdomen has developed the per- manent number of sets, 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 post- abdomen gradually assume the proportions of the 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 Oypris 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. In the genus Cypridopsis the body of the post-abdomen is bud 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 Oypridop-— sis. Not only that, but the unbanded forms of this stage correspond very closely to Cypridopsis hystrix Herrick.* Indeed, when this stage - *C. L. Herrick. Contribution to the Fauna of the Gulf of Mexico and theSouth, 1887. P. 30, Pl. , Fig. 6. ENTOMOSTRAGA OF MINNESOTA. 329 - was first encountered, it was supposed to be a Cypridopsis. While working at its anatomy a specimen with the markings characteristic of Cypris herricki 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 tothe 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 LX XVIII. Length 0.5mm. Height 0.28mm. Width 0.35 mm. This isa 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 from 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: C. agilis Haldeman (78), C. discolor Haldeman (78), C. scabra Haldeman (78), C. simplex Hal- deman (78), ©. vitrea Haldeman (78), C. 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 a 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 a genus Cypris. In this paper Professor Sars’ description has been € a 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 Erpetocypris (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 weleome 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 antenne 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.— a aurantiacus Jurine (98), p. 173; Pl. XVIII, Figs. 5-12. 1821.—Cypris fusca Straus (205), p. 59; Taf. I, Figs. 1-16. 1844.— ‘‘ aurantia Zaddach (234), p. 37. 1844.—? ‘‘ opthalma Koch (102), H. 36, p. 17. 1850.— ‘‘ aurantia Baird (5), p. 159; Taf. XIX, Fig. 13. 1853.— ‘‘ ineongruens Liiljeborg (118), p. 119; Taf. IX, Figs. 6-7; Taf. XI, Figs. 1-4; Taf. XII, Fig. 6. 1855.— ‘‘ aurantiaS. Fischer (65), p. 650; Pl. I, Figs. 29-31, 60, 61. 1868.— ‘‘ incongruens Brady (18), p. 73; Pl. X XIII, 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.— ‘* incongrwens Wenzel Vavra (221), pp. 95-98; Figs. 32, 32+-32°. 1893.— ‘‘ ineongruens C. H. Tarner (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. ~ ENTOMOSTRACA OF MINNESOTA. 331 Viewed from above (Fig. 10) the shell is ovoid, pointed in front 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, Fias. 11-13; LXIX, Fies. 22-31. 1892.—Cypris sp. (2) 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 4 nine, sub-central. Color, various shades of greenish yellow. The 4 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. 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. Viewed from end (Fig. 25) shell is oval, a little higher than wide. Antennules (Fig. 25) and antenne as usual in genus Cypris. The mandible (Fig. 26) terminates in four large teeth; between each two of these teeth there is a short, slender rod. The mandibular palp consists of four joints. The first joint is very large, about as large as the combined lengths of the other three; it bears about the middle of — its dorsal surface a branchial appendage, which in turn bears four long sets; and from the distal fifth of its ventral surface arise two long sete. The antepenultimate joint is very short; from the distal half of its dorsal surface arise two long sete and one short one. The - penultimate joint is long; from its disto dorsal extremity arise three long and one short sete; from the disto-ventral angle of the shell arise two short sete. The terminal joint is very narrow and about = short as the antepenultimate joint; at its tip it bears four short claws. The biarticulate claws on the first mandibular process of the first maxilla are smooth. The first foot of the male (Fig. 27) is composed of five joints. The second joint is large. The antepenultimate joint is about as long as the preceding joint. From its disto-caudal margin arises a medium sized seta, and from its disto-cephalic margin arises a somewhat smaller seta. The terminal joint is about the same size as the penul- timate. From its disto-caudal margin arise a medium size seta and a small spine; from its disto-cephalic margin arises a very short spine. From the distal end of joint arises a long claw; the claw is about as long as the combined lengths of the three distal joints. The claw is composed of a short basal and a long terminal portion. At the disto- caudal portion of the basal joint of claw there is a short seta; at the disto-cephalic margin of the same joint there isa somewhat smaller seta. A row of fine hairs extends along the middle portions of the caudal margin of the terminal joint of the claw. In the second foot of the male the antepenultimate joint is medium sized. From about the middle of this joint arises a median seta, and from the disto-caudal margin a long seta. The penultimate joint is the longest joint; from its disto-cephalic margin arises a median spine. The terminal joint is about as long as the antepenult; from the middle of its cephalic border arises.a short seta; from its tip arises a short seta; from its tip a more or less curved short claw and a median seta. The post-abdomen (Fig. 29) of male is curved. At its tip there is a long claw and a short seta. Entad of this terminal claw is another long claw; further entad arises a short seta. Post-abdomen of female is straighter, otherwise the same. , San ae ae ee Qnty» Sarin, Mater NG TD heise, ENTOMOSTRACA OF MINNESOTA. 333 In the male there is a pair of verticillate sacs (Fig. 30). From the distal extremity of each arises a vas deferens. Length of sac 0.35 mm. ; width 0.11 mm. The copulative organ of male consists of distinct halves, each half of which is composed of a large basal and a small ; terminal portion. The basal portion of each division receives at its a proximal end a vas deferens. Length of copulative organ 0.37 mm.; q width 0.11 mm. _ Habitat: Small weedy ponds or canal basins. I have not found these very often; but whenever found they were very abundant. On one occasion I found a pool containing millions of males, but not a single female. Specimens of this species have been found at Cincin- ‘ nati, Ohio. (Turner, 213.) Cyprinotus burlingtonersis Turner. PLATE LXX, Fias. 14-23. 1894.—Cypris burlingtonensis C. H. Turner (215), pp. 17-19; Pl. VII, Figs. 14-23. — —-:1894.— ** — burlingtonensis C. H. Turner (216). Length of the female 1.6mm. Width 0.89 mm. Height 0.93 mm. Length of the male 1.3mm. Width 0.7 mm. Height 0.7 mm. The length of the shell is a little less than twice the width and the height is about equal to the width. The shell is very thin and is covered with long hairs (Fig. 15). The shell is also marked with ‘ certain dark bands, which are due, in part at least, to the internal ) organs shining through the translucent shell. , Viewed from the side (Fig. 17) the shell is sub-oval, but the cephalic extremity is wider than the caudal. The dorsal margin is convex, the greatest convexity being nearer the cephalic than the caudal ex- tremity. The cephalic and caudal margins are convex. The ventral = _ Margin is nearly straight. Viewed from above the shell is sub-elliptical, the two extremities being more or less pointed (Fig. 17) and of about equal width. In some specimens the ends are round. The sides are feebly convex, indeed in some parts they are almost straight and nearly parallel. Viewed from the end the shell is nearly circular, the sides being very convex. The antenna consists of five joints (Fig. 20), the fourth joint being very long and slender. The distal joint is narrow, being no wider _ than the base of the terminal claws. The terminal claws are slender and the distal portion of each is fringed by a longitudinal row of very fine teeth. The natatory sete extend to a short distance beyond the _ tip of the terminal claws. ‘ea 334 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. The second joint of the mandibular palp bears, in addition to the usual set, a short, plumose, dagger-shaped seta (Fig. 18). The ter- minal claws of the palp are slender and smooth. The two prominent spines upon the first mandibular process of the first maxilla bear teeth (Fig. 16). The palp of the second maxilla terminates in three long flexible spines. The middle spine is longer than the whole palp, but the lateral ones are only about two-thirds as long as the middle one. The first foot (Fig. 21) is five-jointed, the third and fourth joints being distinct. The second joint is broad and is as long as the united lengths of the next three joints. The terminal claw is longer than the united lengths of the last three joints. The distal third of the cephalic margin of this claw is finely pectinated. The claw upon the last joint of the second foot (Fig. 23) is curved and is about twice as long as the terminal joint. The post-abdominal rami (Fig. 19) are slender and-straight. The terminal claws are long and slender, being about half as long as the ramus. They are straight and one margin of the tip of each is finely pectinated. The lower claw is fully three-fourths as long as the distal one and resembles it in structure. Habitat: These are found in great numbers in a shallow grassy pool at Burlington, Ohio. They were found in the early part of March, 1893, just after the close of a long and severe winter; indeed, there was a light snow-fall the day before the collection was made. Judging by the lay of the land, I think that the pool dries up in summer. . At Atlanta, Georgia, just after some heavy rains in January, 1894, large numbers of these active creatures were found in several shallow pools in the South River bottoms. These pools dry up in warm weather. The specimens remained for about two weeks and then dis- appeared. Length 1.58 mm.; height 0.94 mm.; width0.91mm. Jones Creek, Kent county, Delaware, March 3, 1894, collected by Professor L. D..Hileland. These were immature specimens about 1.4 mm. long. Cyprinotus grandis Chambers. PLATE LXXIX, Fias. 1-9. —.—Cypris grandis V. T. Chambers (41), pp. 151-152, Fig. 1. 1887.—Cypris grandis C. L. Herrick (86), p. 32. Length 3.60 mm. Height 2.09 mm. Width 1.39 mm. ‘*Valve oblong, slightly sub-reniform, highest behind the middle, sloping thence regularly toward the anterior end, with a slight bulge on the hinge-margin just where it rounds off in front. Greatest thick- ness about the middle. In side view somewhat resembling Brady’s | A ‘ ; ‘ . : Bi ENTOMOSTRACA OF MINNESOTA. 335 figure of C. tessellata (Trans. Linn. Soc., v. 26, Pl. 23, Fig. 39), but this species is longer in proportion to height and. has the highest point of the dorsal margin a little farther behind. Ventral margin very slightly emarginate. In dorsal and ventral view somewhat resembling Brady’s figure of Macrocypris minna (loc. cit., Pl. 28, Fig. 34). Right [? left] slightly overlapping the left [? right]; surface smooth, with minute punctures and short hairs, but with a group of scattered, large sordid, yellowish punctures about the middle of each valve. Color bluish-white (nearly that of thin milk), though some specimens show \ a decided pale greenish tinge. Basal joint of superior antenne with two short sete above and one below; second joint witha single short one below; third with two short unequal sets above and one below; fourth with two above like those of the third, and two long ones below; fifth as the fourth; sixth with the two upper setz as in the third and fourth, but with four long ones below; seventh with two long and two ; shorter sete. Inferior antenne with one moderately long and two j | r. * . ] a y n : y ary short claws, and two sete from the end of the last joint, and with four long claws (one shorter than the other three), and one moderately long Seta, and one long one from the end of the penultimate joint, besides r. four rather long ones above, and two beneath about its middle. Third joint with the usual single stout seta from its end beneath, and the usual fascicle of five long and one short one above near the end, and the usual articulated process. Post-abdominal ramus similar to that of _ C. incongruens as figured by Brady (Joe. cit., Pl. 23, Fig. 20), but longer, having three unequal sete, the terminal one longest. Seminal gland very similar to that of Notodromas monachus (loc. cit., Pl. 37, Fig. 36). Length + of an inch; height ;';; greatest thickness ~,. Probably the largest known species of the genus. It is abundant in the ponds along the upper Arkansas river in the Mount Harvard region, at an altitude E of about 8,000 feet. When first taken, my specimens were brownish es: from adhering mud, but alcoholic specimens have the livid white color 4 above mentioned. The lucid spots are indistinct and difficult to make x out; there are about nine, the two anterior obliquely transverse and long, the two posterior small.’’ (V. T. Chambers.) 4 Habitat: Upper Arkansas river in Mount Harvard region. (VY. T. K Chambers. ) 4 Z FAMILY DARWINULIDA. : ‘‘Antenne destitute of swimming setz and of poison gland and ? duct. Mandible-palp three-jointed; the basal joint large and densely Bi -setiferous. Two pairs of jaws, the first bearing a large branchial plate, the second a smaller branchial plate and a pediform palp. Two pairs of feet external to the valves. Post-abdominal lobes sub-conical, ‘small.’”? (Brady and Norman.) 336 GEOL. AND NAT. HIST. SURVEY OF MINNESOTA. 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 set. Antenne four-jointed, and bearing four or five strong; a 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 set, bearing also a small lamina, fringed with branchial filaments; second joint long, slender, and nearly 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 sete 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 LXXXIJ, Fies. 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 f : \ Lae se ee Oe DP es ~ *) oi : : ih RAD. OL cel sy n Fy AU a ae ee Nags, ight 3: i 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 set 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. stevensoni. 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. The second foot is not bordered by a fringe of hairs, For arrangement of the setz 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 setz 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. ‘ . + oh aghhy bile sft, sh Ne e SEN ri Magners a vee i” , ‘ 2 AND fa AT eS PLANATIONS <3 } . > rx, keane fear hai Fote tre, cage La EXPLANATION OF PLATE I. - i] ee be a tm or co 90 Limnocalanus macrurus Sars. Left foot of the fifth pair in the male. Right foot of the same pair. Foot of the fifth pair in the female. Abdomen. Eurytemora affinis Poppe. Female from above. Right antenna. Fifth foot of female. Feet of fifth pair in the male. First foot. One of the swimming feet. Pseudodiaptomus pelagicus Herrick. Lateral view of female with ovisac and spermatophore. Fifth feet of female. Fifth feet of male. Portion of right male antenna. One of the swimming feet. Abdomen of male. Antennules. Nore.—All details are from females unless specified, and where the parts in thesexes are alike the drawing is always from the female. > , P Yi ; - ce y Q>», Py yp ~ emma 1 lel LEA Re Ne y ERY ao Hd) epee rae RNS WON roast y i Sy Qf Me ena a PLATE L ZooL. SURVEY OF Miny., II, 1895. tnd KH ic) al — | Au ay © Z =) -EXPLANATI Diaptomus leptopus Forbes. 1. Lateral view of female. Shaded portions purple. 2. Dorsal view of the male. To the same scale. 3. Abdomen of the female from above. 4. Fifth foot of the female. 5. Maxilliped. 6. Antennule. 7. Fifth foot of the male. 8. Fourth foot of the female. 9. Right antenna of the male. 10. First foot. All the figures are from specimens taken near Minneapolis, Minne- sota. Mostly camera lucida drawings copied mechanically. BULALPE I: ie EXPLANATION OF PLATE LIL. eid aN >4 a Wt i“ a: a ed « ey - ba » * ate 3 ee . Mh ay eh Pees 2 Pas: pe Diaptomus stagnalis Forbes. | @ ee ea eet et ee he ee ie Female from above. Male from above. Portion of male right antenna—a variant. Stylet of the female. Fifth foot of the female. Fifth feet of the male. Antennule. Maxilliped. First foot of the male. First foot of the female. 11. Third foot of the male. 12. Fourth foot of the male. All the figures from camera drawings. From specimens secured in Granville, Ohio, in spring. oy = BE. IL. PLAT. 1895. J Zoot. Survey or Minn., II SSP boos Diaptomus pallidus Herrick. Lateral view of preimago oe female. Right antenna of male. Fifth feet of the male as they usually appear. Fifth feet of the female. From Minneapolis specimens. Feet of fourth pair. Fifth feet of the male, showing the true nature of the appendages of the left foot. The inner ramus of the left foot is not shown in the figure. Diaptomus oregonensis Liiljeborg. Right antenna of the male. Fifth feet of the male. Fifth foot of the female. Palpus of the mandible. Left foot of the fifth pair according to Lilljeborg. End of the female antenna. All but Fig. 11 from specimens from Lake Minnetonka, near Min- neapolis, Minnesota. nt PLATE Iv. , 1895. Il ’ SuRVEY OF MINN. + } 4 “4 i it _ . i ' < ; i | . ; an i ] ry pa = , Pe os ? % > a ° Je ; j \ : ue 4, Sere) Cee ee ee =a <3 4 = _ jae ic o) ra © —_ eH _ Z oe = < = C. Fy co) Z ) —_ = < Zz << a Ay va = eo, ~ ya Oot ea Diaptomus albuquerquensis Herrick. Fifth feet of the male. Extremity of the right antenna of the male. Fifth foot of the female in one-jointed condition. Diaptomus ashlandi Marsh. Extremity of the right antenna of the male. Fifth foot of the female. Fifth feet of the male. Diaptomus novamexicanus Herrick. Female, from above. Portion of the right antenna of the male. The hyaline plate on the antepenult segment is incorrectly represented as depressed in the middle. Fifth foot of the female. Fifth feet of the male. Cyclops ater Herrick. Fifth foot. * ater Herrick. Fourth foot. * _ eapilliferus Forbes. Antenna. PLATE yi: BP i eee Rofo _ Survey or MINN | neat” _ EXPLANATION OF PLATE Sane? wr s PS St Oo sO. e > 11. Diaptomus albuquerquensis Herrick. Dorsal view of the female. Appendages omitted. Camera. Lateral view with antenna and egg sac. Camera. Dorsal view of the abdomen. Camera. One of the feet of the fifth pair in the female. Camera. Second antenna. Jaw and its palp. Outer maxilliped. Foot of the first pair. Foot of the second pair. Extremity of the male right antenna. The fifth feet of the male. Camera. PLATE VIL II. 1895. MINN. a DOL. SURVEY OF by SS 00. BA Shy Sot RO ke Diaptomus gibber Poppe. Fifth foot of male. 6 ee 6s 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. EP ries PLATE VIII. 7 » par a oe Diaptomus ee ee 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. ceruleus 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. ee ee = + SURVEY OF Minn., LI, 189s. PLATE 1X; >. ATE X. F PL Y “ : : : o ee ‘ a es & /) | ’ ee as re “Wy 7S L Sy \ i iWaiveesere- ss ~~ PLATE XIV. NSS ee Relies 7 ] pi € ie . st = Ses Cele EY OF Minn., II, 1895. . ages ” ATION OF PLATE XV. 10. it fed no oh) Cyclops signatus var. coronatus. Outline from above of a mature female. Outline of a male. Fifth foot. One of the fourth pair of feet. Cyclops signatus var. tenuicornis. Tip of the antenna of the female. Fifth foot. Stylet of the female. Cyclops serrulatus. Foot of the second pair. Foot of the fourth pair. Fifth foot. Stylet of the female. Type. 1895. RVEY oF MInn., PLATE XV ZE yy —Yv Cit i) ys ° ee R= RS ~I28 ’ IT SS I ee ae Ss WA ee Sights a! 4 ’ ’ ‘ 7 . ‘ ‘ | 1} _ ; r * h \ . r Pi ‘ ps * ity . . p * aS g ‘ 34 “;% J ? “ ‘ * ‘ . A, a ws i ee LANATION OF PLATE XVI. hey 5 aa Aa oe ae a pe | et Cyclops leuckarti Sars. Camera outline of body seen from above. Antenna. Camera. Caudal stylet. Camera. Terminal segments of antenna to show armature. Fifth foot. Camera. Outer maxilliped. Camera. Inner maxilliped. Camera. Foot of first pair. Camera. Foot of second pair. Foot of fourth pair. Camera. Opening of the spermatheca. OL. Survey or MINn., II, 1895. PLATE RVI > as EH < 4 py a i) Zi = _ a ; < 5 Fourth foot. Ae oh 1 aS. . habe Cyclops phaleratus. Outline of the male from above. Stylet of the male. Fifth and sixth feet of the male. Antenna of the male. Antenna of the female. ° Fifth foot of the female. Cyclops fimbriatus. Stylet. Antenna of the female. Cyclops languidus. Antenna of the female. Fifth foot. PLATE XV LI: Survey oF Minn., II, 1895. OL. H = S K <2) ei < = Ay Fy 2) A (i ba . a ee ' . F . eS a ‘ a s ci ee < eae 3 3 ze & hap? Ay Fe ‘ Adi 5 - ; f eal : © a | A A oO . e . = ae eS 5 =< v9 . ee j Qu si b< : ; J > . i". . Male. . First foot. Abdomen. Fifth foot. Stylets. Antenna. Cyclops phaleratus. Female. 2 3. Under surface of abdomen. 4. Last joints of antenna of the female. 5 The spine of the distal segment of outer rg incorrectly shown as curved. ey 6. Fourth foot. 7. Stylets. 8. Fifth foot. 9. Antenna. Cyclops serrulatus. Cyclops diaphanus. Cyclops gracilis. Cyclops varicans. PLATE, XEX: e é *; ¥ a . y = Kes a bo: SI OIE 9 Cyclops signatus var. tenuicornis. Female. Mandible. Mavxille. 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. Eye. Antenna of male. Cyclops signatus. End of antenna. hy PLATE XX. = =) Zoo. Survey or Miyy., II, 1895. os es —_ ee eek te 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. Cy clops signatus. Fourth foot. ater. Inner ramus of fourth foot. ‘i ater. Stylet. . sp.? First foot. ff parecus. Fifth foot. Chydorus globosus. First foot of male. sp.2. Terminal segments of fourth foot. —— “. vy m PEATE. XX ey 2 > Pas ~ « , ’ t Lin eA ey: if ayy Sh ares 3 bw Wet « ‘ ic meta: fa wee ia 4 rr a Me as Th Vt 7 3 ars) L. SURVEY oF Minn., II, 1895. J — = eee = Se N SSS +> ay tives ne cna, Coe i LANATION OF PLATE XXII. ry ngs 12. 13. 14. 15. rk ae We a NS eal ee ale ee Canthocamptus minnesotensis. First foot. Stylets. Antenna of female. Fifth foot of female. Fifth foot of male. Antenna of male. Daphnia hyalina (D. galeata). Young. 6 ee ce Male. -Camptocercus leucocephalus. Male. -Alonella execisa. Male. Cyclops insignis. Outer ramus of the first foot. Fifth foot. Fourth foot. Sty let. Worm parasitic in arterial sinus of Daphnia schaefferi. Zoo. SuRVEY OF Minwn., II, 1895. PLATE. XXII } ie = 29 a * fey Stylet. ¥s Cyclops brevispinosus. Antenna. Outer ramus of fourth foot, terminal segment. Fifth foot. Cyclops 6e wequoreus. After Brady. insignis. Abdomen. insignis. Receptaculum, after Schmeil. pareus. Fourth foot. bisetosus. Receptaculum, after Schmeil. bisetosus. Stylet. bisetosus. Fifth foot. strenuus. Receptaculum, after Schmeil. strenuus. Fifth foot. abyssorum. Fourth foot. ae eee wie. —Zoor. Survey or Miyy., II, 1895. PLATE XXII. \ PLANATION OF PLATE XXIV. “ / Fie. ey i se Bes ‘ 2, oe 3. . 4. Bee pb, x : 6. S: = Nes a: 2 8. Bast: 9. es: a ent § I< am Lie BS q % 13. Ergasilus depressus. Male. Cyclops leuckarti, deep-water variety, = C. tenuis si Stylets. : . Fifth foot. rea Antennule. ‘. | f Fourth feet. : vi Antenna of male. Cyclops brevispinosus. Stylet. Inner maxilliped. . Swimming foot. Apchts Wat Fifth foot. ae Antennule. Opening of receptaculum Cyclops sp.? Nauplius. s PLATE XXIV. gE ALLO AE EEE ELEEE —> re SV PAPAS O SD OF 4 | ZooL. SURVEY oF Minv., II, 1895. K a (ea) - % =) op) =| © e) N 7 = i b K a H < 4 Ay a jo) Z oO ke a 2 Latonopsis occidentalis. 1. Female from above. 2. Ephippial (?) female from the ae ; 3. Ordinary female from the side. 4. Antenne with usual armature. — 5. Inferior angle of shell. 6. Antennule. PLATE XXX VIM. Survey or Mrinn., II, 1895. ZOOL. OF: PLATH, XK XIX 2 < f ; ae Fess See ‘ a pn - ‘ ‘<8 as i a | . a} ~ te }, -- x \ Lt * i Te é > «4 i A, hee oY key + a - <4 ’ 4 Be is be? ¢ Moina rectirostris Mueller. Female with summer ova. Portion of the shell near the postero-inferior angle. | Post-abdomen. 4 a Antennule. Moina brachiata Jurine. Female with summer ova. Antennule. The lateral flagellum is omitted. Post-abdomen. 5 : ze First foot of female. Moina paradoxa Weismann. Ordinary form. PLATE XXXIX. . Zoo. SURVEY oF MINy., IT, 1895. ll iz on \ —\ T&S A Sarit) ie 3 Ly, kK VARs oN) i Kis my BX. SU i My Lag» y) Sx YZ \ SOT Ah = le Se an ead A a 7 Bvt a8 Fe, LANATION OF PLAT “sf XP E “A pies . es ee ay Maa oy Hee a ‘ c s Nod : $ eee ’ a rest We 8 ° Moina paradoxa Weismann. 1G a 1. Adult female with ephippium. Antenne omitted. > 2. Male, from the side. 2 3. Adult female with summer eggs, seen from below. 4. View ofthe head, from the side. St, stomach; cw, ccecum of sa Br, brain; ant, antennule; f, flagellum of same; Jb, labrum Giioaree ey, eye; mb, mandible. 5. First foot of male: Ke 6. Antennule of male. oY 7. First foot of female. All the figures are camera drawings from New Mexican spe ch PLATE Xb. II, 1895. ’ ZooL. SURVEY OF MINN. 4 ret. ra Ly i: ‘ it ape ' ai . i ros » eT a ve ess - Wer tae ‘ = Set =! aA - . Moina paradoxa. Abdomen of female from Minnesota. Neo +3 Spine from post-abdomen. 2 * — rectirostris. Post-abdomen. 3. * paradoxa. Head of female, showing: (a) eye with pigment and lenses, ()) supra-cesophageal ganglion, antennule with (c) its muscles, (d) its nerve, and (e) its terminal sensory filaments, (f) the cecum of stomach, (g) optic ganglion, (A) stomach, (7) esophagus, (j) the muscles which move the eye, also part of the labrum. 4. ~ paradoxa. Antenne. 5. rectirostris. Ephippium. 6. * paradoxa. Ephippium. re 3 rs Seminal cell. Fass 4 os A group of seminal cells less magnified. 8. rectirostris. Seminal cells. S * paradoxa. First foot of male. 10 * yeetirostris. First foot of male. (From Weismann). 11. ej oy Male. (From Weismann). 12. Ceriodaphnia rotunda. Head. 13. - punctata. te 14. 4g pulchella. 15. * reticulata. ** 16. ~ quadrangula. ** 17 ~g = ‘6 (Variety. ) 18. i Post-abdomen. 19. “ pulchella. > 20. . megops. Hi 21. . reticulata. 3 22. laticaudata. ee 23. % rotunda. 4. Figures 12-23 are after P. E. Mueller. ) Oy ee aes ae, C PLATE XLI. 4 s - = - ‘ - 7 . . , A rh. Se 4 [ » ? > Pa a * . ¥ LY A, * ae | a t ¥ ee a I a oe ERY POTS | eke ae EDS ae ota {ine api uees ti: Ys Seta é ER ae sp Eon ere ees e =y rk, Mea a eee ot er a ; e ta ’ Ge >, act Na bf, | “> i Pe Ae “ Pia ga : ; \ Y a Fic. ; fk 1. Ceriodaphnia rotunda. Male (after Kurz). : 2. ae alabamensis. Female. 3: ah reticulata. Post-abdomen of male with openi vas deferens (after Weisman D). ah ; 4. x consors? | “A Ceriodaplhnia scitula. . 5. Head of female. Noe eae Be 6. . Post-abdomen:, 4° 4 : 7. Antennule of male. | : 8. Semen cells of male. ts . 9. Secapholeberis angulata. Adult female. 9a. ‘s angulata. First foot. be 10. 4; armata. Adult female. a se i armata. From below. | 5 Ofryoxus gracilis. i 12. Young, : - 13. Labrum. ty 14. Antennule. oy ‘ > 15. Last foot. Purple pigment in lower part. q E \ . \ s / Py / sax stoi ee i. ate : 2 mee Le wh eye tre i ak i ba ae 5 oe Gakic b. mF ZOOL. SURVEY OF Minvn., II, 1895. PEATE eEie EXPLANATION OF PLATE’ XLUL. m nhc Ua) Te ke ee 7 Moina brachiata. 1. Leg of fifth pair, after Lund. . pee 2. Leg of third pajr. | 3. Ceriodaphnia reticulata. Leg of filth pair. TRY . . Scapholeberis mucronata. 462 ; “" s 7 : il aah) a 1 eee 4,“ Post-abdomen. pea ae ret cr ere: 5. Foot of second pair. 4 1 ts! OE a 6. Foot of fourth pair. ae shes? ae TAR 7. Female, seex from above. ie r. pes PEA TE SLU \ Beg SP ete ee OO ae tis ~~ ww a or) Lon] - _ z ca a to (e) > fa > x D cop) J ie} ° N 24) Se ~~. a eae hae ee Oe eee aaa Oe ee a LS HH es ia Pie a) << ra By Re es SS pe o <= eae a ¥ as ei po ee S. AS ¥ * fi% pe ite Ke . ¢ . / Ceriodaphnia scitula. 1. Head. 2. Post-abdomen. . F Ceriodaphnia reticulata. 3. Post-abdomen. . 4. Head. Ceriodaphnia consors. Post-abdomen. _ Head. Simocephalus vetulus. Foot of second pair. ‘ or ; 7 - — a ~ - 23 . o 7 “ 3 w on 7” - my > < : aA ‘a. a : es i vs teal? ; i: ee “ ” te ae: * o . ea ; ‘ se eee pase Fey - Ab T tie ie ee er Re “ nan et ‘, ey: tee Vd tomes — eget 3 De Fadl Ba hls coe wait Zoot. SURVEY OF Minn., II, 1895. PLATE XLIV. PLATE XLV. wes 2) Z © < Z, fa D dp) iJ e) [e) N LI. (PLANATION OF PLA mH brs a Daphnia scheefferi. aS Post-abdomen of female. Post-abdomen of male. Male antennule. Brain and nerves. Inf. c. g., infra-cesophageal ganglion with nerves to antenne; ce., 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; ¢, frontal nerve; d, nerve to antennules; e, commissure connecting upper and lower cesophageal ganglion; f, nerves to antenne and mandi- bles. [After Claus. ] re ma. PLATE. GE Zoot. SuRvEY oF Minn., II, 1895. KH Pie] ea Y = | ar ies S 4, (es) st |