. Bulletin - United States National Museum. Science. 202 BULLETIN 57, UNITED STATES NATIONAL MUSEUM. cutting edge, the third niuch wider, subterete, with three or four tubercles. Canines well developed, simple, with distinct though rather small cingulum and no secondary cusps. Cheek teeth both above and below strictly normal, ni ^ and ni - rather narrow on inner edge and with hvpocone absent or very imperfectly developed, ni ^ with three commissures and four or five cusps, according to the varying condi- tion of the metacone, rii ... with second triangle smaller than first, but with all the el
. Bulletin - United States National Museum. Science. 202 BULLETIN 57, UNITED STATES NATIONAL MUSEUM. cutting edge, the third niuch wider, subterete, with three or four tubercles. Canines well developed, simple, with distinct though rather small cingulum and no secondary cusps. Cheek teeth both above and below strictly normal, ni ^ and ni - rather narrow on inner edge and with hvpocone absent or very imperfectly developed, ni ^ with three commissures and four or five cusps, according to the varying condi- tion of the metacone, rii ... with second triangle smaller than first, but with all the elements of the tooth complete. Skull slender and lightl}' built, without special ix'cidiarities of form, the I'ostrum nearly as .ong as braincase. tlie (h'j)tli of bi'aincase, including audital l)ulla. about e<|ual to mastoid bivadth, the sagittal crest low, but usually distinct, the palate (lee])ly cmarginate in front, abruptly contracted behind, the sides of its posterior exten- sion parallel. Audital bulhv well devel- oped and covering more than half sur- face of cochlea?, but simple in form and not A^ery large, their diameter about equal to the distance between them. Ear well developed, slender, occasionally rather large; tragus slender and nearly or <|iiite straight. Foot very variabh^ in size, but never peculiar in form. Tail about as long as outstretched leg. Inter- femoi'al membrane large, its surface furred at extreme base above. /SjH'clcx ('.)'(///u'iK'd.—I have examined about half the known forms of Myotis. I\e})Ki)'ks.—Myotix ai)pears to be the most primitve genus of Vespertilionida?, as it not only retains the maximum ninnber of teeth known in the order, l)ut it also has the slightest i)ossible degree of special modifica- tion in extei'ual Fig. 31.—Pizonyx vivesi. Gitaymas. Mexico. No. 123701. xU. Genus PIZONYX Miller. loot;, /'izdin/.r I'roc. IViol. So I'.HIC). 'ton. XIX. ]). ;>, .luiie 4. Tiipc-^pecn'x.—Myot'ts rire
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Keywords: ., bookauthorun, bookcentury1800, bookdecade1870, booksubjectscience
