MISCELLANEOUS PUBLICATIONS MUSEUM OF ZOOLOGY, UNIVERSITY OF MICHIGAN, NO. 120 A Synopsis of Recent North American Microtine Rodents BY EMMET T. HOOPER AND BARBARA S. HART ANN ARBOR MUSEUM OF ZOOLOGY, UNIVERSITY OF MICHIGAN JUNE 26, 1962 MISCELLANEOUS PUEEEICATPONS MUSEUhZ OF ZOOLOGY, UNPVEIiSITY OF MICHIGAN The publications of the Museum of Zoology, University of Michigan, consist of two serics-the Occasional Papers and the Miscellaneous Publications. Both series werc founded by Dr. Bryant Walker, Mr. Bradshaw H. Swales, and Dr. W. W. Newcornb. The Occasional Papers, publication of which was begun in 1913, scrve as a medium for original studies based principally upon the collections in the Museum. They are issued separately. When a s~iificientnumber of pages has been printed to make a volume, a title page, table of contents, and an index arc supplied lo libraries and indi- viduals on the mailing list for the serics. The Miscellaneous Publications, which includc papers on field and museum tcch- niclucs, monographic studies, ancl other contributions not within the scope of thc Occasional Papers, arc publishetl separately. It is not intended that they bc grouped into volumes. Each number has a title pagc and, when necessary, a tablc of conlcnts. A complete list of publications on Birds, Fishes, Insccts, Mammals, Mollusks, and Reptiles and Amphibians is available. Address inquiries to the Director, Museum of Zoology, Ann Arbor, Michigan. No. 24. A conlparative life history study of the mice of the Genus Peronlyscus. By ARTHURSVIIILA. (1932) 39 pp. ................................. $0.50 No. 25. The moose of Isle Royale. By ADOLPHMURIE. (1934) 44 pp., 7 pls.. .. $0.70 No. 26. Mammals From Guatemala and British Honduras. By ADOLPI-IMURIE. (1935) 30 pp., 1 pl., 1 map ........................................ $0.35 No. 32. Following fox trails. By ADOLPHMURIE. (1936) 45 pp., 6 pls., G figs.. $1.00 No. 38. Revision of Sciurus variegatoides, a species of Central American Squirrel. By WILLIAMP. HARKIS,JR. (1937) 39 pp., 3 pls., (2 colored). 3 figs., 1 map ...........................................................$0.50 No. 39. Faunal relationships and geographic distri1)ution of mammals in Sonora, Mexico. By WILLIAMH. BURT. (1938) 77 pp.. 26 maps ........... $0.75 No. 45. Territorial behavior and populations of some small mammals in southern Michigan. By WILLIAMH. BURT. (1940) 58 pp. ............. .out of print No. 46. A contribution to the ecology and faunal relationships of the mammals of the Davis Mountain Region, southwestern Texas. By W. FRANKBLAIR. (1940) 39 pp., 3 pls., 1 map ....................................... $0.35 No. 51. Mammals of the lava fields and adjoining areas in Valencia County, New Mexico. By EMMETT. HOOPER. (1941) 47 pp.. 3 pls., 1 map.. .... $0.50 No. 52. Type localities of pocket gophers of the Genus Thomoinys. By EMMET T. HOOPER. (1941) 26 pp., 1 map ............................... $0.25 No. 58. A systematic review of the Neotropical water rats of the Genus Nectomys (Cricetinae). By PHILIP HERSHKOVITZ.(1944) 88 pp., 4 pls., 5 figs., 2 maps ........................................................... $1.15 No. 59. San Francisco Bay as a factor influencing speciation in rodents. By EMMETT. HOOPER. (1944) 89 pp., 5 pls., 18 maps ................ $1.25 No. 72. Faunal relationships of Recent North American rodents. By E~IMRTT. HOOPER. (1949) 28 pp. .......................................... $0.35 No. 73. A study of small mammal populations in northern Michigan. By RICHARD H. MANVILLE.(1949) 83 pp.. 4 pls., G figs., 1 map ................. $1.25 No. 77. A systematic review of the harvest mice (Genus Reithrodontomys) of Latin America. By EMMETT. HOOPER. (1952) 255 pp., 9 pls., 24 figs., 12 maps ..................................................... $4.00 Cloth bound ...................................................... $4.60 R/IISCELLANEOUS PUBLlCATlONS MUSEUM OF ZOOLOGY, UNlVEKSITY OF MICHIGAN, NO. 120 A Synopsis of Recent North American Microtine Rodents BY EMMET T. HOOPEK AND BAKBAKA S. HAK'T ANN ARBOR MUSEUM OF ZOOLOGY, UNlVERSlTY OF MICHIGAN JUNE 26, 1962 CONTENTS PAGE MATERIALSAXD METHODS......................................................... 5 FEATURESOF THE GLANSPENIS IN THE MICROTINAE.................................. 8 DESCRIPTIONSOF GLANDES......................................................... 12 North American Species ..................................................... 12 Group I ................................................................ 12 Group I1 ............................................................ 23 Group I11 ...............................................................33 Old World Species ...........................................................41 SYNOPSISOF CRANIALAND EXTERNALCHARAC'ERS .................................... 46 Dental Characters ........................................................... 46 Other Cranial Characters .................................................. 51 Estcrnal Characters .......................................................... 53 DISCUSSION...................................................................... 54 Morphological Affinities of the Spccies as Indicated by the Glans .................54 Classification ................................................................61 LITEMTUREC~ED ................................................................ 66 ILLUSTRATIONS FIGURES IN TEXT FIGUHliS 1'AGE 1 . Schccnatic view of a l~licrotil~eglans penis .............. ...... 9 2 . Clans peiiis of Dicl-osto~tyx 101-qucttus ...................... ....... 14 3. Glans penis of Neofiber alleni ........................................ 16 4 . Claiis pcnis of Phe1tacorr7ys lo17gicc~udus.............. ....... .... 18 5 . Glans pcnis of Synof~lorttysborealis. S. cooperi, Phe~trrcortrys inlct.trredit~.s,Lerrtrt~us sil~il-ictcs ....................................................20 G . Glans pcnis of O~rdntrnzibetlticn. Lnguru.s cur-tatu.s, 111io-ottes longicatrrlrcs, Cletlt,-i. orlott~ysgo$l)eri, C . rutilus ulbiuerltel., Mio-otu.5 towtzse~tdi,M . ~t~ontctttus,Clclltri- otto~tt)lsr7~lilus duwso~ti ......................................... 25 7 . Gla~rspc~iis of Micl-olus pet~~tsylvunictes ...... ......... ...28 8. Gla~~spc~ris of Micr-otus oecotlotttlls, M . r~iclra~dso?ti,At . ot.egolzi, &I . rtri~rrzrs ..... 32 9 . Glans pcnis of Microtus guatett~alell~is,M . ccrlifo~~?ticus,11l . i~i,telorutrr, M . oclll-ogastel-. M . ~trexicanles ............................................ 57 10 . Glans pcnis of Alicrolus f~iluive~tler...................................... 40 11. Glans pcnis of Ellobi~lstcllpi?tus .................................. 43 A SYNOPSIS OF RECENT NOKTH AI\llERICAN IvIICROTlNE RODENTS TULLBI'.~~;(1899), Rittera (1918), Tokuda (1934, 194l), Ognev (1948, 1950) and others have described the glans penis in various species of inicrotines and have enlployed the resulting data in systematic analyses of the rodent [;tuna of Europe and Asia. As a result of their efforts there is a sizable body of iulor~iiationregarding Old World microtine glandes and their usefulness in classification. There are no conlparable data on North Ainerican iilicl-0- tines although there are several studies of the structural core of the glans which indicate that the baculum provides useful clues to affinities ol micro- tine species. The inost important of these studies are by Hamilton (1946), Dearden (1958), and Anderson (1960). Described here are glandes of 33 species of microtines, 25 of them North A~uericanand eight of the Old World. Most of the North American species are represented, and our study is focused on them, but also it necessarily was extended to some Old World species. In addition to describing and comparing the glandes, we have attempted to couple those data with infor- nlation derived from skins and skulls and thereby to form an opinion as to classification of New World microtines. As here understood the sub- I'anlily Microtinae is as defined by Hinton (1926) and Simpson (1945). RlATERIALS AND METHODS The glandes which were measured and sketched and served as the prime source of new basic data are listed below (New World species ar- ranged in systematic order following Hall and Kelson, 1959, and Old World species listed alphabetically by genus). Other specimens, which were incom- plete or poorly preserved or which were used as supplementary material, are excluded here but are mentioned in the text. No~.r.rrAMLRICA. Clell?rio~ior~~ysgnf~jjeri: Ontario, 1. Colorado, Rocky Mt. Park, 1. Montana, Park Co., 3. Clelhrio?io~~iys1-1~fi1u.s: Alaska, 2. I'lrc~i~ncoitryi?ller?riedius: Montana, Missoula Co., 2; Madisoil Co., 1. Colorado, Rocky Rft. Park, 1. I'11crtncottiy.s lo?7:,.icnttdus: California, Sonolna Co., 4, Microlus ~~eii17sylvni1icus:Michigan, Shiawassee Co., 7; Washtcnaw Co., 1. M. ?troiztnnu.s: Montana, Carbon Co., 1. Wyoming, Johnson Co., 2. M. cnlifoi-,ticus: California, Contra Costa Co., 2. M. torc~~lvelzrli:Washington, Mason Co., 2. Oregon, Clatsop Co., 1. M, oecoi~o~nu.~:Alaska, 5. G IiOOPER AND IIAR1- Af. loi~gzrotrdur:Montana, Caibo11 Co., 3. IVashington, Chelan Co., 1. Af. ?rrc~xicaiz~is:Mexico, Vera Cruz, 2. At. f~~lr~iveiller:Mexico, Oaxaca, 4. A1. (At11aco1try.s)1-icliardsoi~i: IYyoming, Teton Co., 1. Montana, Park Co., 1; Carbon c:o., 2. A!. (CIli10lis.s) orego~li:Washington, hlasoti Co., 1; Olyrlipic Natl. I'ark, 1. California, Hnmboltlt Co., 1. Oregon, Clatsop Co., 1; .l'illarnouk Co., I. Af. (Stei~orrnizi~r,s)tttit~i-t~s: Alaska, 3. Af.