4 OCCASIONAL PAPERS MUSEUM TEXAS TECH UNIVERSITY Yellowhouse Canyon, forged by the Double Mountain Fork of the Brazos River, appears just such a dispersal route (see Fig. 2). The mouth of this canyon is situated near the previously mentioned collecting sites near Post, in Garza County. The head of the canyon is located near Buffalo Springs Lake in Lubbock County, another locale from which B. taylon is known. Places near South¬ land and Slaton where the pygmy mouse has been collected also are along Yellowhouse Canyon. Further expansion westward across the High Plains appears unlikely where such canyons meet areas of intense agricultural activities, as occur in Lubbock and Garza counties. However, further trapping and investigation along the escarpment and accompanying canyons may yet reveal more distribution records for the pygmy mouse. Where such canyons originate in areas of suitable habitat, the species might be expected to continue its westward expansion into the High Plains. Acknowlegments We thank L. W. Robbins for his help in collecting specimens, and R. L. Robbins for reviewing an earlier draft of this manu¬ script. Literature Cited Davis, W. B. 1974. The mammals of Texas. Texas Parks and Wildlife Dept., 41:1-294. Hall, E. R. 1981. T he mammals of North America. Ronald Press, New York, 2:vi+601-l 181+90. Hall, E. R., and K. R. Kelson. 1959. The mammals of North America. Ron¬ ald Press, New York, 2:viii+547- 1083+79. Packard, R. L., and H. W. Garner. 1964. Records of some mammals from the Texas High Plains. Texas J. Sci., 16:387-390. Packard, R. L., and F. W. Judd. 1968. Comments on some mammals from western Texas. J. Mamm., 49:535-538. Address of Authors: Department of Biological Sciences and The Museum, Texas Tech University , Lubbock, TX 79409. Submitted 12 May, accepted 20 June 1982. OCCASIONAL PAPERS THE MUSEUM TEXAS TECH UNIVERSITY NUMBER 86 23 JUNE 1983 HISTOMORPHOLOGY OF THE FEMALE REPRODUCTIVE TRACT IN PHYLLOSTOMOID BATS Craig S. Hood and James Dale Smith Studies on the female reproductive organs of Chiroptera have shown that bats possess an amazing diversity of anatomical and functional specializations compared to other groups of mammals (Rasweiler, 1979a; Wimsatt, 1975, 1979). Bats possess more varia¬ tion in uterine morphology than any other mammalian order; pteropodids and emballonurids have primitive duplex uteri, whereas bicornuate and simplex uterine morphologies have evolved within other chiropteran families (Mossman, 1977). De¬ spite this diversity in uterine morphology, there has been little synthesis towards a general understanding of the evolution of this complex organ in bats. Robin (1881) was apparently the first to provide a comparative morphological study of female genitalia in bats. He examined 45 species of 10 currently recognized families and documented the tremendous diversity in the gross morphology of the chiropteran uterus. Although he did not comment extensively on the phy¬ logenetic implications of his findings, Robin suggested that some phylogenetic relationships could be predicted on the basis of uter¬ ine morphology. Wood Jones (1917) considered female internal and external genitalia in 19 species of eight currently recognized families. He proposed that several types of uteri are found among families of bats. The duplex uteri of pteropodids and the highly fused uteri of phyllostomids (including mormoopids) were estab¬ lished as unique extremes among these types. Although the duplex uterus of pteropodids is distinct compared to that found in most other bat families, it is apparently a primitive uterine mor- 2 OCCASIONAL PAPERS MUSEUM TEXAS TECH UNIVERSITY phology and, as such, does little to resolve phylogenetic relation¬ ships among bats. On the other hand, the uteri of the New World families Noctilionidae, Mormoopidae, and Phyllostomidae appear to be uniquely derived among bats. If the highly fused uterus of these chiropteran families represents a shared-derived feature, then it predicts a close phylogenetic relationship for noctilionids, mormoopids, and phyllostomids. The systematic relationships of noctilionids, mormoopids, and phyllostomids have been studied extensively in recent years. Sev¬ eral independent data sets suggest that these bats share uniquely derived features that indicate close phylogenetic relationships (Walton and Walton, 1968; Smith, 1972, 1976; Patton and Baker, 1978; Luckett, 1980). On the basis of these shared-derived features, recent authors have regarded noctilionids, mormoopids, and phyl¬ lostomids as members of a monophyletic group, and have placed them in the superfamily Phyllostomoidea (for use of superfamilial and familial names, see Handley, 1980). The present paper reports the results of a comparative histo- morphological study of the uterus, oviducts, and ovaries in the New World families Noctilionidae, Mormoopidae, and Phyllo¬ stomidae. The reproductive biology of noctilionids and phyllo¬ stomids has been well studied in only six genera, including Noc- tilio (Anderson and Wimsatt, 1963; Rasweiler, 1977, 1978), Desmodus (Wimsatt, 1954; Wimsatt and Trapido, 1952; Quintero and Rasweiler, 1974), Macrotus (Bradshaw, 1962; Bodley, 1974; Bleier, 1975) Glossophaga (Hamlett, 1935; Rasweiler, 1972, 1974, 19795), Carollia (Bonilla and Rasweiler, 1974), and Artibeus (Wis- locki and Fawcett, 1941; Tamsitt and Valdivieso, 1963, 1965; Fleming, 1971). Virtually no information exists on the reproduc¬ tive biology of mormoopids (Wimsatt, 1979). The purpose of this paper is to present a comparative data set on reproductive histomorphology of phyllostomoid bats. It is hoped that this study will provide a stimulus for future research on the reproductive biology of individual species. In addition, because phylogenetic relationships of these three families have been well studied through several independent data sets, the use¬ fulness of female reproductive histomorphology in testing phy¬ logenetic hypotheses can be assessed. Phylogenetic implications are treated in detail elsewhere (Hood and Smith, 1982). Materials and Methods Specimens used in this study were obtained from natural populations. Whole female reproductive tracts were excised, then fixed in Zenker’s or Bouin’s solution HOOD AND SMITH— HISTOMORPHOLOGY 3 (Humason, 1972). Reproductive tracts also were removed from formalin-fixed museum specimens. The quality of fixation in this latter material varied greatly; in many cases only general anatomical relationships could be ascertained. The reproductive status of individuals used in this study included most stages of the female cycle. Many specimens had early-implanted blastocysts, although some late- pregnant uteri also were examined. The former condition is especially informative regarding oviductal histomorphology and in defining sites of implantation (Ras- weiler, 1977, 1979«). Specimens in later stages of pregnancy were less useful in de¬ scribing uterine morphology because of displacement or destruction of tissues by the developing embryo. Histological Procedures Tissues were processed through paraffin, serially sectioned at 6-8 micra, and stained with Mallory’s Trichrome (Humason, 1972) or Gomori’s One Step Tri¬ chrome Method (Thompson, 1966:788). The Gomori Trichrome staining method is capable of discriminating epithelial, connective, muscular, and vascular tissues and has been applied to the study of complex organs (Bhatnagar and Kallen, 1979; Bhatnagar, 1980; Smith and Madkour, 1980). Organization of connective tissues is especially well demonstrated by the light green component of the stain, a feature important for detailing oviductal penetration into the uterus (see Rasweiler, 1974, for a similar discussion concerning Masson’s Trichrome). One modification of the Gomori Method was found to improve our results. The standard treatment with hot Bouin’s solution (56°C) for one hour frequently led to sections loosening from the slides. This undesirable effect was remedied by substituting this treatment with 12 to 18 hours in room temperature (20°C) Bouin’s solution; staining intensity was maintained with excellent clarity. Most of the reproductive tracts were sectioned in the frontal plane although a few were prepared in transverse section. Reconstruction of the histomorphology of the female reproductive organs was accomplished by examination of serial sec¬ tions. Each reproductive tract, so examined, was compared to photographs and or drawings taken before the specimen was prepared histologically. Out-group Comparison and Phylogenetic Characters One of the goals of comparative studies is to present primary descriptive accounts that can be used to assess phylogenetic relationships. A logical frame¬ work for the testing of phylogenetic hypotheses has been presented by Hennig (1966) and discussed by Smith (1980). Luckett (1980) has emphasized three impor¬ tant aspects of phylogenetic character analysis. Ihese include: I) determining the homologous or homoplastic nature of shared similarities among organisms; 2) identifying and arranging character states into transformation series; and .3) deter¬ mining the relative primitive or derived nature of these character states. In the present paper, histomorphological features are desnibed and are hypo¬ thesized as primitive (plesiomorphic) or derived (apomorphic) on the basis of the out-group comparison method (Watrous and Wheeler, 1981). 1 his will provide a basis for subsequent cladistic analyses. Representatives from the following chirop- teran families were examined as out-groups to noctilionids, mormoopids, and phyllostomids: Pteropodidae, Emballonuridae, Rhinolophidae, Hipposideridae, Vespertilionidae, Mystacinidae, and Molossidae. Literature reports were used to determine character distributions in other eutherian orders. 4 OCCASIONAL PAPERS MUSEUM TEXAS TECH UNIVERSITY Specimens Examined Reproductive tracts (116) of the following taxa were examined (numbers in par¬ entheses indicate sample size): Pteropodidae: Rousettus amplexicaudatus (2); A lyc- timene albwenter (2); Eonyctens spelaea (2); Macroglossus lagochilus (2); AT min¬ imus (2); Emballonuridae: Rhynchonycteris naso (1); Balanliopteryx plicata (2); Taphozous longtmanus (1); Saccopteryx bilineata (3); Rhinolophidae: Rhinolo- phus denti (1); Hipposideridae: Hipposideros caffer (1); H. diadema (2); Noctili- onidae: Noctilio albiventris (3); N. leponnus (1); Mormoopidae: Pteronotus macleayi (2); P. parnellu (6); P. quadndens (3); Mormoops blainvillii (1); Phyl- lostomidae: (Phyllostominae) Micronyctens hirsutus (1); AT megalotis (1); Macro- tus californicus (4); Phyllostomus discolor (4); P. hastatus (1); Phylloderma stenops (1) ; Trachops cirrhosus (1); (Glossophaginae) Glossophaga soncina (3); Monophyl- lus redmani (1); Leptonyctens curasoae (2); Lonchophylla robusta (2); Anoura geoffroyi (1); (Carolliinae) Carollia castanea (1); C. perspicillata (3); C. subrufa (1); Rhinophylla pumiho (3); (Stenoderminae) Sturnira lilium (4); Uroderma biloba- tum (2); Vampyrops helleri (2); Vampyrodes caraccioli (1); Vampyressa pusilla (3); Ectophylla alba (1); Artibeus jamaicensis (4); Enchisthenes hartii (1); Ariteus fla- vescens (1); Ametrida centuno (1); Centuno senex (2); (Brachyphyllinae) Brachy- phylla cavernarum (1); Phyllonycteris aphylla (3); (Desmodontinae) Desmodus rotundus (2); Vespertilionjdae: Myotis adversus (1); AT californicus (2); AT evotis (2) ; AT emarginatus (1); AT lucifugus (1); Pizonyx vivesi (1); Pipistrellus hesperus (3) ; Rhogeessa tumida (1); Scotophilus kuhlii (1); Plecotus townsendu (1); Antro- zous pallidus (i); Mystacinidae: Mystacina tuberculata (2); Molossidae: Tadanda braziliensis (1); T. plicata (1); Eumops trumbulli (1); Molossus molossus (1). Uterine Histomorphology General Description The mammalian uterus is a complex, tubular organ which var¬ ies considerably in gross morphology. The primitive eutherian uterus is hypothesized to have consisted of two uterine horns (cornua); these open independently into the vagina (Mossman, 1977). Some members of the Chiroptera (see below), Dermoptera, Tagomorpha, and Rodentia have retained this primitive arrange¬ ment, whereas derived uterine morphologies have evolved inde¬ pendently in many mammalian orders. Derived morphologies apparently have developed by progressive, caudal to cranial fusion of the uterine horns resulting in the formation of a median, common uterine body. This progression involves two aspects of the uterine horns: 1) superficial tissues of the cornua fuse, and 2) following this external fusion, the internal uterine lumina may become confluent by degeneration of the median septum. How¬ ever, it is possible that the internal uterine anatomy may be retained in a relatively primitive separated condition despite external fusion of the uterine cornua. HOOD AND SMITH— HISTOMORPHOLOGY 5 On the basis of gross morphology, both primitive and derived uteri are found within the Chiroptera. All chiropteran families examined in this study (except phyllostomoids) have relatively long uterine horns and moderately short, common uterine bodies. In contrast, the uteri of noctilionids, mormoopids, and phyllo- stomids have short uterine horns and a prominent, common uter¬ ine body; most phyllostomids have a completely simplex uterus. I he mammalian uterus is composed of three histologically well-defined tissue layers. An outer serosa is continuous with the peritoneum and, together with associated mesenteries and liga¬ ments (broad, round, and suspensory), supports the uterus. The thick, middle tunic (myometrium) is comprised of smooth muscle fibers; this layer constitutes a large portion of the uterine wall. Ihe innermost layer (endometrium) is a mucosa of simple columnar epithelium with associated glands, supported by an underlying connective tissue (lamina propria). The endometrium undergoes marked cyclic changes during reproduction. The cau¬ dal end of the uterus constitutes the cervix; this region has a dis¬ tinct mucus-secreting epithelium and a dense connective tissue stroma. Cervical histomorphology has been discussed at length in a number of mammalian orders, including primates, rodents, car¬ nivores, and artiodactyls (Hafez and Jaszczak, 1972; Hafez, 1973 a; Graham, 1973; Kanagawa and Hafez, 1973). Caudally, the cervix projects into the vagina as a rounded or conical mound — the por- tio vaginalis. The cervicovaginal junction is abrupt in most mammals, but varies considerably within primates and bats (Gra¬ ham, 1973; this study). In all chiropteran families examined in this study, the free uter¬ ine horns wrere comprised of well-defined myometrium and endometrium; these uterine tissues constitute the gestational por¬ tion of the uterus. On the other hand, the common uterine body is comprised of two histologically distinct regions. These include an endometrial-lined gestational portion and the cervix. In the pteropodids and emballonurids examined in this study, the com¬ mon uterine body is extremely short. I he cervix constitutes most of this externally fused portion, whereas only a small amount of the gestational uterus is involved. In all other chiropteran families examined (except phyllostomoids), the common uterine body is longer, but, nonetheless, it is mostly comprised of cervical tissue (Fig. 1). However, in noctilionids, mormoopids, and phyllostom¬ ids, the common uterine body is extremely large; the gestational uterus constitutes a major portion, whereas the cervix is limited to 6 OCCASIONAL PAPERS MUSEUM TEXAS TECH UNIVERSITY TAPHOZOUS LONGIMANUS HIPPOSIDEROS DIADEMA PIPISTRELLUS HESPERUS TADARIDA PLICATA Eig. 1. — Semidiagramatic, frontal sections of the uterus, oviducts, and ovaries of representative chiropteran families, including Emballonuridae: Taphozous longi- manus\ Hipposideridae: Hippostderos dmdema ; Vespertilionidae: Pipistrellus hes- perus ; Molossidae: Tadanda plicata. The oviductal lamina propria is shaded to outline the oviduct as it contacts and enters the uterus and to indicate the depth of penetration of the intramural junctura. Abbreviations: ov, ovary; ovd, oviduct; olp, oviductal lamina propria; utj, uterotubal junction; myo, myometrium; end, endometrium; cs, cervical stroma; cf, cervical folds; va, vagina; cl, common uterine lumen. HOOD AND SMITH— HISTOMORPHOLOGV 7 Fig. 2. — Semidiagramatic, frontal sections of the uterus, oviducts, and ovaries of phyllostomoid bats. Noctilio albwentns represents phvllostomoids that have a bicornuate uterus, whereas Glossophaga soricina is representative of phyllostom- oids with a simplex uterus. The presence of tubular, intramural uterine cornua (iuc) is a unique feature of the phyllostomoid simplex uterus. Abbreviations can be found in Fig. 1 . the caudal end of the uterus (Fig. 2). This external uterine anat¬ omy, and predominately gestational common uterine body, is considered a shared-derived (synapomorphic) feature of phyllo¬ stomoid bats. Cervical histomorphology of phyllostomoid bats is typical by eutherian standards; the cervical canal has a distinct mucous- secreting epithelium which is thrown into prominent cervical folds. All phylostomoid bats have a rounded or conical portio vaginalis and a clearly defined cervicovaginal junction. Internally, all pteropodids examined to date and Taphozous longimanus (family Emballonuridae) have completely separate uterine lumina; these have two cervical openings into the vagina (Fig. 1). In all other chiropteran taxa examined, the uterine lu¬ mina join within the common uterine body forming a single canal and cervical opening. In the emballonurids Rhyne honycte- ns, Balantiopteryx, and Saccopteryx , rhinolophids, hipposiderids, and Mystacina (family Mystacinidae), this common uterine lumen is limited to the cervix, whereas in vespertilionids and molossids there is a short portion which is lined with gestational uterine tissue (Fig. 1). 8 OCCASIONAL PAPERS MUSEUM TEXAS TECH UNIVERSITY Fig. 3. — Semidiagramatic, frontal sections of the uterus, oviducts, and ovaries in representative bicornuate phyllostomoids, including Noctilionidae: Noctilio albi- ventris ; Mormoopidae: Pteronotus parnellii ; Desmodontinae: Desmodus rotundus; Phyllostominae: Macrotus californicus. A unique feature of Noctilio and Desmo¬ dus is the presence of an endometrial ridge (er) in the antimesometrial walls of the uterine cornua. Abbreviations can be found in Fig. 1. Among phyllostomoid bats, noctilionids have retained markedly separate uterine lumina (Fig. 2). This internal uterine anatomy is similar to that of several chiropteran out-groups (see especially vespertilionids and molossids) and is considered a retained primi¬ tive (plesiomorphic) feature for phyllostomoids. On the other hand, the internal uterine anatomy in mormoopids and phyllo- stomids consists of a large endometrial-lined common uterine lumen; this fused internal anatomy is herein considered a syn- apomorphy of these two families (Fig. 3). In the systematic accounts that follow, variations in external and internal uterine anatomy among phyllostomoid bats are considered. HOOD AND SMITH — HIS rOMORP HOLOG V 9 Family Noctilionidae This Neotropical bat family includes those bats that are referred to as the bull-dog bats or fishing bats. It includes two species in one genus, Noctilio (Corbet and Hill, 1980). rhe uterus of Noctilio albiventris has been described in detail by Anderson and Wimsatt (1963) and we confirm their results. The uterine cornua are short and bulbous, with a prominent common uterine body. Internally, the uterine lumina are not fused throughout the entire length of the common body. An extremely short common lumen is formed just cranial to tfie cer¬ vix. Anderson and Wimsatt (1963) noted that a ridge exists in the antimesometrial walls of the cornua; these ridges serve as sites of implantation (Fig. 3; Rasweiler, 1978, 1979a). It will be noted below that endometrial ridges are also found in the vampire bat, Desmodus rotundus. The one specimen of Noctilio leponnus examined in this study had histomorphological features identical to that described above for N. albiventris. This specimen possessed an early-implanted blastocyst near the cranial end of an endometrial ridge. This site of implantation is similar to that observed in N. albiventris. In noctilionids, the degree of fusion of the external uterine horns is shared with mormoopids and Desmodus. Other phyllo- stomids have uterine morphologies that are further specialized. On the other hand, the relatively separate internal uterine anatomy of Noctilio is shared with other chiropteran families examined herein. Family Mormoopidae The bats of this family are called moustached, naked-backed, or ghost-faced bats. These include two genera ( Pteronotus and Mor- moops) and eight species; all live in the Neotropics (Smith, 1972). The uterine histomorphology of this family has not been de¬ scribed previously. Externally, both Pteronotus and Mormoops have relatively short uterine horns and a prominent common uter¬ ine body (Fig. 3). The cornua are markedly asymmetrical,, the right side being anatomically and physiologically hypertrophied (Wimsatt, 1979:346, table 1; this study). The enlarged right uterine horn is similar in size and shape to both symmetrical horns of Noctilio (Fig. 3). Unlike noctilionids, the internal uterine lumina are fused throughout most of the length of the common uterine body form¬ ing a large common lumen. In one specimen of Pteronotus par - 10 OCCASIONAL PAPERS MUSEUM TEXAS TECH UNIVERSITY nellii, an early-implanted blastocyst was found in the cranial end of the right cornua. The blastocyst was implanted in the anti- mesometrial wall; however, orientation of the embryonic mass was not determined. Endometrial ridges were not noted in either horn of any mormoopid examined (Fig. 3). Family Phyllostomidae Bats of this family are referred to as New World leaf-nosed bats. This is an especially diverse family, including six subfamilies, 49 genera, and 143 species. All live in the New World tropics and subtropics (Jones and Carter, 1976). Uterine morphology in phyllostomids is extremely diverse and illustrates progressive fusion of both external and internal uterine anatomy. Patterns of variation in phyllostomid subfamilies are considered in detail below. Subfamily Desmodontinae. — This subfamily includes the true vampires; three monotypic genera include Desmodus , Diaemus, and Diphylla. Anatomical and behavioral adaptations for sangui- vory (blood feeding) have led many researchers to regard the vam¬ pires as a separate and distinct family, albeit related to phyllo¬ stomids. However, this and other recent studies suggest that these bats are within the context of the Phyllostomidae (Machado- Allison, 1967; Forman et ai, 1968; Smith, 1972). The reproductive biology of Desmodus rotundus has been stu¬ died extensively (Wimsatt, 1954; Wimsatt and Trapido, 1952; Quintero and Rasweiler, 1974). Compared to other phyllostomids, the uterine histomorphology of desmodontines is primitive. Externally, the uterus of Desmodus has short uterine horns and a long, common uterine body (Fig. 3). The cornua are symmetrical and tubular, and join to form a common uterine body which is only as wide as either horn. Overall, this uterus is distinctly Y- shaped. I he internal uterine lumina join immediately within the com¬ mon uterine body forming a large common lumen. This internal anatomy agrees with that described above for mormoopids. A low endometrial ridge exists in the antimesometrial walls of the cor¬ nua (Fig. 3); as in Noctilio, these ridges serve as a site of implan¬ tation (Quintero and Rasweiler, 1974). Subfamily Phyllostominae. — This subfamily includes bats that are known as big-eared, round-eared, sword-nosed, and spear¬ nosed bats. It includes 11 genera and 34 species that are widely distributed in the New World tropics and subtropics. HOOD AND SMITH — HISTOMORPHOLOGY 1 1 Based on uterine histomorphology, members of this subfamily can be arranged in two distinct groups. Macrotus californicus, Micronycteris lursutus, M. megalotis, and Trachops cirrhosus possess uteri with extremely short cornua and a prominent, com¬ mon uterine body; these taxa are herein referred to as the Macrotus- group (Fig. 3). Compared to other bicornuate phyllo- stomoids (i.e., noctilionids, mormoopids, and Desmodus), the external cornua are additionally fused. This external uterine anat¬ omy is considered a synapomorphy of the Macrotus- group and other phyllostomids exclusive of Desmodus . Internally, the uterine lumina join to form a large common uterine lumen; internal uter¬ ine anatomy is similar to that observed in mormoopids and Des¬ modus (Fig. 3). Anatomical and physiological asymmetry has been noted in Macrotus by Bradshaw (1962) and Bleier (1975); the right uterine horn is dominant. In all Macrotus californicus examined in the present study, this asymmetry was noted. Although several uteri from subadult individuals were symmetrical in shape, all adult uteri had hypertrophied right cornua. LTteri of Micronycteris and Trachops examined in this study were identical to pregnant and/or nonpregnant uteri of Macrotus. In contrast to the Macrotus- group, the uteri of Phyllostomus discolor , P. hastatus, and Phylloderma stenops are externally sim¬ plex; these taxa are herein referred to as the Phyllostomus -group. Members of the Phyllostomus -group have externally simplex uteri with a tubular- to pear-shaped form (Fig. 4). The fundus of the uterus is prominent and rounded. The simplex uterus is regarded as the most highly derived external uterine anatomy among phyl- lostomoids. The internal uterine anatomy of the Phyllostomus- group con¬ sists of a large common lumen and narrow tubular segments. These tubular segments are actually extremely short uterine lu¬ mina and constitute the intramural uterine cornua (ICC; Fig. 4). In one specimen of Phyllostomus discolor we discovered an early- implanted blastocyst in an ICC (Fig. 5). Virtually nothing is known concerning uterine histomorphol- ogy in Phylloderma stenops (Wilson, 1979). The uterus of one specimen examined in this study was reproduct ively inactive. Uter¬ ine histomorphology of this species was identical to Phyllosto¬ mus. Subfamily Glossophagmae. — Bats of this subfamily are referred to as the long-tongued or long-nosed bats. As their name implies, 12 OCCASIONAL PAPERS MUSEUM TEXAS TECH UNIVERSITY PH YLLON YCTERIS APHYLLA Fig. 4. — Semidiagramatic, frontal sections of the uterus, oviducts, and ovaries in representative simplex phyllostomoids, including Phyllostominae: Phyllostomus discolor ; Brachyphyllinae: Phyllonycteris aphylla ; Carolliinae: Carollia perspicul- lata\ Stenoderminae: Artibeus jamaicensis. The intramural uterine cornua (iuc) is a unique feature of the phyllostomoid simplex uterus. Abbreviations can be found in Fig. 1. they have highly specialized, elongated muzzles. This subfamily consists of 13 genera and 32 species that live in the New World tropics and subtropics. All members of this subfamily have externally simplex uteri (Fig. 5). Although some variation exists between genera, glosso- HOOI) AND SMITH — HISTOMORPHOLOGY 13 Fig. 5. — Initial sites of implantation and orientation of blastocysts in Annum geoffroyi (top) and Phyllostomus discolor (bottom). In both specimens, blastocysts were implanted in the intramural uterine cornua and the inner cell mass was oriented towards the uterotubal junction of the oviduct i psi later al to the develop¬ ing corpus luteum. Abbreviations: ul, uterine lumen; bla, blastocyst; arrows in both photomicrographs indicate orientation towards the oviduct. Both 116X. 14 OCCASIONAL PAPERS MUSEUM TEXAS TECH UNIVERSITY phagines have a distinctly barrel- to pear-shaped uterus. 1 he fun¬ dus was notably flattened in all taxa examined. Internally, glos- sophagines have a large, common uterine lumen and tubular IUCs. The IUCs are short and broad in Lonchophylla and Lep- tonycteris, but longer in Glossophaga, Monophyllus, and Anoura (Fig. 6). Rasweiler (1974) has done extensive studies on the form and function of IUCs in Glossophaga soricina and noted that initial implantation always occurs in them. Likewise, we dis¬ covered an early-implanted blastocyst in an IUC of a specimen of Anoura geoffroyi (Fig. 5). Furthermore, in preovulatory specimens of Leptonyctens and Monophyllus , the endometrial lining of the IUCs was preferentially proliferating compared to that of the common lumen. These data suggest that IUCs function as the primary sites of implantation in all glossophagines. Subfamily Brachyphyllinae. — This subfamily includes those bats referred to as the flower-bats. It contains three genera and seven species, all of which live in the West Indies. The systematics of this subfamily have been discussed by Baker and Bass (1979) (see Baker, 1979, for justification for using the name Brachyphyl¬ linae rather than Phyllonycterinae). Uterine histomorphology in brachyphyllines agrees in all qualitative respects with that observed in the Glossophaginae (Figs. 4, 6). In both Brachyphylla and Phyllonycteris the uterus is externally simplex and barrel- to pear-shaped. The fundus is flattened and not prominent. The internal uterine anatomy of Phyllonycteris aphylla includes a large, common lumen and short IUCs. These IUCs are oriented towards the latero-fundic border, an arrangement similar to that found in Lonchophylla and Leptonycteris. Although none of the P. aphylla examined had implanted blastocysts, all uteri had moderately to greatly proliferating endometrium lining the IUCs. These observations suggest that IUCs in Phyllonycteris function as in other phyllostomids with simplex uteri. I he one specimen of Brachyphylla cavernarum examined in this study possessed a large embryo. Unfortunately, invasion of embryonic tissues into the fundus of the uterus was so extensive that some uterine features could not be determined. Although IUCs were not observed, the oviducts descended from the latero- fundic border as in Phyllonycteris. Additional uteri of Brachy¬ phylla could be profitably studied; presence of functional IUCs would be predicted based on their occurrence in Phyllonycteris. Subfamily Carollnnae. — Bats of this subfamily are called short¬ tailed, leaf-nosed bats. These include two genera ( Carollia and Rhinophylla) and eight species; all live in the Neotropics. HOOD AND SMITH— HISTOMORPHOLOGY 15 Fig. 6. — Semidiagramatic, frontal sections of the uterus, oviducts, and ovaries in representative Glossophaginae, including Lonchophylla robusta, l.eptonycteris curasoae, Glossophaga soricina, Anoura geofjroyi. Abbreviations can be found in Fig. 1. Both Carol li a and Rhinophylla have externally simplex uteri (Fig. 4). Bonilla and Rasweiler (1974) did extensive studies on uter¬ ine and oviductal histomorphology in Carollia. All species of Carollia examined in the present study had broadly pear-shaped uteri. The internal uterine anatomy includes a large, common 16 OCCASIONAL PAPERS MUSEUM TEXAS TECH UNIVERSITY lumen and long, tubular IUCs. We observed that blastocyst implantation occurs in the IUCs as in Glossophaga soricina (see also Bonilla and Rasweiler, 1974; Rasweiler, 1972, 1979a). In contrast to Carollia, the uterus of Rhinophylla pumiho is less pear-shaped and more tubular in form. Internally, the uterus has a large, common lumen and short IUCs. No data were availa¬ ble regarding the function of IUCs as a site of implantation. Subfamily Stenoderminae. — This subfamily includes those bats referred to as the New World fruit-eating bats. It includes 17 gen¬ era and 60 species. Although taxonomically diverse, stenodermines are a rather homogeneous group. Bats of the genus Sturnira have been considered a separate subfamily by some authors; however, recent workers regard this genus as a member of the Stenodermi¬ nae (Jones and Carter, 1976; Baker et ai, 1979). All stenodermines have distinctly tubular, simplex uteri (Figs. 4, 7). The fundic end of the uterus is covered by the oviducts which enter the uterine body near the midsaggital line. The internal uterine anatomy consists of a single common lumen without IUCs. This simple internal anatomy is a unique feature of this subfamily and distinguishes the stenodermine uter¬ us from all other simplex forms. The loss of IUCs is considered a continuation of uterine fusion involving the internal lumina and, as such, is considered a synapomorphy of the subfamily. In the absence of IUCs, blastocyst implantation must occur in the com¬ mon lumen. It has been reported that implantation in Artibeus jamaicensis occurs in the fundic end of the common uterine lumen (Wislocki and Fawcett, 1941; Fleming, 1971). Tikewise, we observed implantation in this region for all specimens that pos¬ sessed blastocysts or embryos. These included two Centurio senex, one Sturnira lilium, one Ectophylla alba, and one Ariteus flaves- cens (Fig. 8). In all cases, the initial site of implantation was in the extreme fundic end of the uterine lumen (blastocyst orienta¬ tion could not be determined except for Ariteus, see Fig. 8). OVIDUCTAL HlSTOMORPHOLOGY General Description An excellent description of oviductal histomorphology can be found in Nilsson and Reinius (1969), whose terminology was fol¬ lowed in the present study. The oviduct is a tubular organ com¬ posed of three histologically well-defined tissue layers. An outer serosa is continuous with the peritoneum and joins the mesosal¬ pinx to support the oviduct. A middle muscularis is comprised of HOOD AND SMITH— HISTOMORPHOLOGY 17 CENTURIO SENEX URODERMA BILOBATUM VAMPYROPS HELLERI STURNIRA LILIUM Fig. 7. — Semidiagramatic, frontal sec lions of the uterus, oviducts, and ovaries in representative Stenoderminae, including Centurio senex, I'roderma bilobatum, Vampyrops hellen , Sturnira lilium. Abbreviations can be found in Pig. 1. circular and longitudinal smooth muscle layers and constitutes the bulk of the oviductal wall. I he third and innermost tissue layer is a mucosa of simple to pseudostratified columnar epithe¬ lium with an underlying connective tissue (lamina propria). The oviductal epithelium undergoes marked histological changes dm- 18 OCCASIONAL PAPERS MUSEUM TEXAS TECH UNIVERSITY Fig. 8. — Photomicrographs of the uterus and oviducts of a specimen of Ariteus jlavescens (serial sections viewed frontally). Top: Oviducts descend through the fundus on the midsaggital line. Bottom : several serial sections later, a blastocyst is found implanted in the fundic end of the common uterine lumen. Orientation of the inner cell mass was towards the oviduct ipsilateral to the developing corpus luteum. Both 50X. ing the reproductive cycle. These changes include activation of secretory cells and development of cilia (Nilsson and Reinius, 1969). I he lamina propria is heavily vascularized and acts as a HOOD AND SMITH— IIISTOMORPHOLOG Y 19 structural framework for the epithelium. This organization is well illustrated as the mucosa is thrown into lamina propria-supported folds. These folds occur throughout t lie oviduct, but may vary in size or number in some regions (Nilsson and Reinius, 1969; this study). The oviducts of phyllostomoid bats are coiled and regionally differentiated as in most eutherian mammals and all out-group chiropteran families examined. Beginning at the infundibular end, the oviductal regions include a preampulla, ampulla, isth¬ mus, and junctura (Fig. 9). For the purposes of this study, these oviductal regions constitute the free portion of the oviduct and are defined herein as the extramural oviduct. That portion of the oviduct that passes through the uterine wall is referred to as the intramural junctura (Nilsson and Rei¬ nius, 1969; Rasweiler, 1974). This oviductal region possesses all the histologically defined tissue layers found in the extramural oviduct, but lacks a definitive serosa. The muscularis is relatively thick and becomes continuous with the smooth muscle fibers of the myometrium. This portion of the oviduct has been the subject of considerable study because it involves the uterotubal junction (UTJ; Lisa et al., 1954; Edgar and Asdell, 1960; Hafez, 19735). The UTJ includes the intramural junctura and its opening into the uterine lumen (Hafez and Black, 1969). Although much of the research concerning the UTJ has been limited to domestic or laboratory mammals, available data suggest that this region has unique anatomical characteristics in some eutherian orders (An¬ derson, 1928; Lee, 1928; Hafez and Black. 1969). The UTJ of bats has not been described in a comparative sense, although it has been discussed by several authors (Rasweiler, 1972, 1974; Karim, 1975; Mori and Uchida, 1980). Among the families and subfamilies of bats examined in the present study, the junc¬ tion possesses considerable variation in form. In vespertilionids and molossids, the UTJ is a prominent colliculus, whereas it is a low papilla in rhinolophids, hipposiderids, and Mystacina, and a complicated, pocketed region in pteropodids and emballonurids (Fig. 1). In contrast, the UTJ in noctilionids, mormoopids,. and phyllostomids has been markedly simplified. The lumen of the intramural junctura opens into the cornual lumen, IUC, or directly into the common uterine lumen without any oviductal or uterine elaboration (Figs. 2, 3, 4). The simple morphology of this region is regarded as a synapomorphy of the superfamily Phyllo- stomoidea. In the systematic accounts that follow, patterns of 20 OCCASIONAL PAPERS MUSEUM TEXAS TECH UNIVERSITY Fig. 9. — Oviductal histomorphology varies considerably among regions of the oviduct. This specimen of Monophyllus redmani was reproductively active, with a large corpus luteum but with no evidence of blastocyst or recent pregnancy. A, Preampulla with external folds (fimbriae) and high, cilliated epithelium; B, ampulla with prominent lamina propi ia-supported folds (arrow) and moderately high, cilliated epithelium; C, isthmus wdth relatively few, moderately low folds (arrow) but high, vacuolated epithelium; D, extramural junctura with narrow lumen and low folds (arrow) that usually lack lamina propria support and low, usually noncilliated epithelium. All photomicrographs 321X. HOOD AND SMITH— HISTOMORPHOLOGV 21 variation in oviductal histomorphology among phyllostomoid bats are illustrated and discussed. Family Noctiliomdae Specimens of Noctilio albiventris and N. leporinus examined in this study possessed the same qualitative features of oviductal his¬ tomorphology. The oviduct of N. albiventris has been described in detail by Rasweiler (1977, 1978) and we confirm his observa¬ tions. I he extramural oviducts enter the uterus at the apical tip of the cornua (Fig. 2). Just outside this entry the oviduct is reflected lat¬ erally, so that the extramural oviduct overlays the cranial end of the uterine cornua. This arrangement is similar to that observed in other bicornuate phyllostomoids and out-group chiropteran families (Figs. 1, 3). The intramural junctura is a short segment which passes through the uterine wall and opens into the cornual lumen. A dense lamina propria supports prominent mucosal folds. These folds line the intramural junctura throughout its length to the UTJ (F igs. 3, 10). The UTJ is simple compared to the chiropte¬ ran out-groups examined; it opens into the cornual lumen with¬ out elaboration. However, it is perhaps noteworthy that the intramural junctura appears to empty into the internal cornual lumen somewhat below its apical tip (Fig. 3). This feature may represent a different mode of oviductal entry, or it may simply reflect the hypertrophied antimesometrial walls of the noctilionid uterus. Rasweiler (1977, 1978) described a dramatic unilateral oviductal reaction in Noctilio albiventris. Under the influence of the active ovary, the ipsilateral oviduct is preferentially stimulated to secre¬ tory activity. Ihe accumulation of glycogen and cytoplasmic vacuolation in oviductal epithelium may be controlled by local vascular pathways (Rasweiler, 1978). In the present study, speci¬ mens of Noctilio albiventris and N. leporinus that were preovula¬ tory or with early-implanted blastocysts had hypertrophied, vacuolated oviductal epithelium. In all these specimens, branches of the ovarian and uterine arteries on the side ipsilateral to the active ovary were prominent and blood-engorged. Family Mormoopidae The oviducts of Pteronotus and Mormoops are short, highly coiled, and regionally differentiated. Entry of the extramural ovi- 22 OCCASIONAL PAPERS MUSEUM TEXAS TECH UNIVERSITY Fig. 10. — Photomicrograph of the intramural oviduct and uterotubal junction (utj) of Noctilio lepormus (frontal section). The oviductal mucosa has lamina propria-supported folds throughout the intramural junctura (see arrow). 279X. duct occurs at the apical tip of the cornua as in other bicornuate phyllostomoids (Fig. 3). As in Noctilio, the extramural oviduct is reflected laterally, covering part of the cranial end of the uterine cornua. The intramural junctura is a short oviductal segment that passes through the uterine wall and opens into the cornual lumen. At the UTJ, the oviductal lumen clearly opens at the extreme apical tip of the internal cornual lumen, an arrangement unlike that observed in noctilionids, but similar to that of Des- modus and the Macrotus-g roup. Mucosal folds are prominent throughout the intramural junctura and are supported by a dense lamina propria. Available data on mormoopid reproductive physiology suggest that these bats are entirely right side dominant (Wimsatt, 1979). All specimens examined in this study confirmed this. In two spec¬ imens of Pteronotus parnellii that possessed early-implanted blas¬ tocysts, the right oviduct was preferentially hypertrophied. How¬ ever, in nonpregnant, preovulatory specimens of P. quadridens and P. macleayii, both oviducts exhibited secretory ability. In addition, branches of ovarian and uterine arteries and veins were seen to course between the ovaries and uterus in specimens of all these taxa (Fig. 1 1). HOOD AND SMITH— HISTOMORPHOLOGY 23 Fig. 11. — Photomicrograph illustrating uterine-ovarian relationships in a speci¬ men of Pteronotus macleayi. Blood vessels (bv) were found between the active right ovary and the cranial end of the right uterine cornu. 378X. Family Phyllostomidae Recent studies have detailed oviductal histomorphology in sev¬ eral phyllostomids, including Desmodus, Glossophaga, and Carollia (Rasweiler, 1972, 1974; Bonilla and Rasweiler, 1974; Quintero and Rasweiler, 1974). These studies suggest that phyllo¬ stomids share features of oviductal histomorphology with noctili- onids and mormoopids. Anatomical relationships between the uterus and extramural oviduct were found to be quite variable among phyllostomids. In those taxa that possess bicornuate uteri (i.e., Desmodus and the Macrotus -group), the extramural oviduct contacts and enters the apical tip of the cornua, an arrangement like that found in nocti- lionids and mormoopids (Fig. 3). On the other hand, phyllostom¬ ids with simplex uteri have a number of distinct forms of oviduc¬ tal entry. In the Phyllostomus- group, the oviducts enter the uterine body on the lateral (mesometrial) bolder (Fig. 4), whereas oviducts in all other simplex forms enter on the fundic border (Figs. 4, 6). This fundic pattern of external entry shows consider¬ able variation among phyllostomid subfamilies. I he site of entry in glossophagines, brachyphyllines, and carolliines is more lateral than in stenodermines. 24 OCCASIONAL PAPERS MUSEUM TEXAS TECH UNIVERSITY Although the extramural oviducts contact and enter the uterus on the fundic border in glossophagines, the site of entry is some¬ what variable (Fig. 6). In Lonchophylla and Leptonyctens , the external entry is on the latero-fundic border of the uterus. On the other hand, the entry in Glossophaga, Monophyllus, and Anoura is more towards the midline. In all glossophagines examined in this study, the intramural juncturae pass through the uterine wall and open into the IUCs. Due to the more lateral site of entry in Lonchophylla and Leptonyctens, the juncturae in those taxa are far apart with a large mass of functional uterine tissue between the oviducts. In Glossophaga, Monophyllus, and Anoura, the more fundic site of entry allows the intramural juncturae to con¬ verge on the midline. As a result, a smaller amount of functional tissue is interposed between the oviducts. Features of oviductal histomorphology in brachyphyllines agree in all qualitative respects with those observed in glossophagines. The site of entry in both Phyllonycteris and Brachyphylla is on the latero-fundic border of the uterus. This site of entry is identical to that of Lon¬ chophylla and Leptonyctens (Figs. 4, 6). Both Carollia and Rhinophylla have extremely long, coiled oviducts. The external entry of the extramural oviducts in Carol¬ lia occurs on the latero-fundic border of the uterus, a site of entry similar to that illustrated in Glossophaga (Fig. 4). However, in Rhinophylla, the external entry is more towards the midline, thus similar to that observed in Anoura. The extramural oviducts of both genera turn laterally and travel along the fundic border of the uterus. Upon reaching the mesometrial border they descend along the sides of the uterine body where they encircle the ovaries. This arrangement is similar to that found in stenodermines. The intramural juncturae of both Carollia and Rhinophylla converge on the midline where they open into the IUCs. The site of exter¬ nal entry and pathways of intramural juncturae result in rela¬ tively little functional uterine tissue being found between the ovi¬ ducts. Oviducts of all stenodermines examined in this study were long and tortuously coiled. Although the external entry of the extra¬ mural oviduct varies to some degree among stenodermine taxa, the entry is very near the midsaggital line in all members of this subfamily. In some taxa (e.g., Uroderma , Vampyrops, Vampy- ressa, Vampyrodes, and Anteus), the site of entry is well off the midline; in others (e.g., Artibeus, Enchisthenes, Sturnira, and Ectophylla) the site is closer to the midline. In the most extreme HOOI) AND SMITH— HISTOMORPHOLOGY 25 cases ( Centurio and Ametrida) the oviducts enter on the midline (Figs. 4, 5, 7, 12). As a result of a fundic external entry and the pathway of intramural juncturae, little uterine tissue is interposed between the oviducts. Functional endometrium was lacking in this region in all but two taxa ( Vampyrops helleri and Vampy- ressa pusilla). In all other stenodermines, the interposing uterine tissue is limited to a dense connective tissue stroma. Resolution of the primitive or derived nature of the lateral and fundic oviductal entries in phyllostomids with simplex uteri is not simple. There are no ontogenetic data available on the devel¬ opment of the phyllostomid simplex uterus, and out-group com¬ parison cannot be readily applied to determine the polarity of this phylogenetic character. However, based on indirect evidence of comparative and ontogenetic studies of the simplex uterus in anthropoid primates and edentates, it appears that a lateral entry is most easily derived from a bicornuate uterine anatomy. In the absence of contradictory evidence, we propose that a lateral entry, as exemplified by the Phyllostomus-g roup, is primitive for sim¬ plex phyllostomids. With progressive uterine fusion, the oviductal junction moves towards the midsaggital line with the result that the fundic entry of glossophagines, brachyphyllines, and carol- liines is regarded as a derived morphology. This progressive movement of the oviductal entry reaches its most highly derived form in stenodermines. The phyllostomid intramural oviduct possesses several unique features. Mucosal folds, prominent in the intramural junctura of noctilionids and mormoopids, were notably reduced in all phyl¬ lostomids examined (Fig. 13). This reduction of mucosal folds begins in the extramural oviduct near the external entry and con¬ tinues to the UTJ. The mucosal lining of some taxa shows low folds, but these are without a supporting lamina propria. Restric¬ tion of mucosal folds to the extramural oviduct is a unique fea¬ ture among bats and is considered a synapomorphy of the family. Unilateral oviductal reactions have been described in Glosso- phaga, Carollia, and Desmodus (Rasweiler, 1972; Bonilla and Rasweiler, 1974; Quintero and Rasweiler, 1974). In this study, these reactions also were observed in the oviducts of preovulatory and early-pregnant specimens of these taxa. Identical unilateral reactions (ipsilateral to the functional corpus luteum) were observed in preovulatory and early-pregnant specimens of the fol¬ lowing phyllostomid taxa: Phyllostomus discolor, P. hastatus, Monophyllus redmani, Leptonyctens curasoae, Phyllonycteris 26 OCCASIONAL PAPERS MUSEUM TEXAS TECH UNIVERSITY Fig, 12. Photomicrographs of the uterus and oviducts of a specimen of Sturnha lilium (seiial sections viewed frontally). Top: Extramural oviducts overlay the fundic end of the uterus before they descend on the midsaggital line. Bottom: This photomicrograph, taken several sections later, illustrates the descent of the intra¬ mural juncturae on the midsaggital line. Both 64X. HOOD AND SMITH— HISIOMORPHOLOG V 21 Fig. 13.— Top: Diagram to illustrate oviductal mucosal fold character: A, muc¬ osal folds present throughout oviduct to the uterotubal junction, as in noctilionids and mormoopids; B, folds lacking in the intramural junctura, as in phyllostomids. Bottom: Photomicrograph of the oviduct and uterus of Glossophaga soricina (frontal section). The oviductal mucosal folds are restricted to the extramural ovi¬ duct as in B. above. Abbreviations: cul. common uterine lumen; ij, intramural junctura; eo, extramural oviduct; asterisk indicates position of the intramural uter¬ ine cornu. 98X. 28 OCCASIONAL PAPERS MUSEUM TEXAS TECH UNIVERSITY aphylla, Ariteus flavescens , Artibeus jamaicensis , and Sturmra lilium. Ovarian Histomorphology Little is known concerning the comparative morphology of the ovary in phyllostomoid bats (Mossman and Duke, 1973). Ras- weiler (1972) briefly commented on the ovaries of Glossophaga soricina. Likewise, Bonilla and Rasweiler (1974) noted interstitial tissues in Carollia. The most comprehensive study on ovarian morphology and histology of a phyllostomid was given by Wim- satt and Trapido (1952) for Desmodus. Ovaries of phyllostomoid bats examined in the present study were generally ellipsoidal to spherical in shape. Notable exceptions included mormoopids and the Macrotus-g roup, which have markedly flattened, atrophic left ovaries. In addition, both specimens of Leptonycteris curasoae had distinctly kidney-shaped ovaries. Ovarian histomorphology in phyllostomoid bats is typical by eutherian standards. A cortex and medulla were readily identified in all phyllostomoids examined; the cortex contained primary fol¬ licles and a dense connective tissue stroma, whereas the medulla contained maturing follicles, corpora lutea, and numerous blood vessels. In most phyllostomoids, primary follicles are distributed throughout the cortex. However, in Glossophaga soricina and Leptonycteris curasoae, these follicle types are limited to the medial and lateral aspects of the ovary, respectively. It has been noted that polyovular follicles occur relatively rarely within mammals (Mossman and Duke, 1973; Harrison and Weir, 1977). In the present study, one young, nonpregnant specimen of Arne- tnda centuno was found to possess numerous polyovular follicles in both ovaries (Fig. 14). Interstitial tissues are diverse; thecal and gonadal adrenal types were present in all taxa examined. In some taxa (e.g., Carollia) massive amounts of gonadal adrenal interstitial tissue were found in the mesovarium and ovarian hilus, observations identical to those reported by Bonilla and Rasweiler (1974). Mossman and Duke (1973:209) noted an unusual rete-type interstitial tissue in Uroderma. In the two specimens of Uroderma examined in this study, the rete epithelium was not active; however, several speci¬ mens of Phyllonycteris and Carollia did have hypertrophied rete epithelium. I he ovary and oviduct are generally suspended by the meso¬ varium and mesosalpinx which together form the ovarian bursa. HOOD AND SMITH — HISTOMORPHOLOGY 29 Fig. 14.— Polyovular follicles were found in both ovaries of a specimen of Ame- tnda centurio ; these ranged in extent of development from small secondary to moderately large vesicular follicles. 240X. Surprisingly, noctilionids, mormoopids, and phyllostomids pos¬ sess a complex array of bursal arrangements. We will briefly summarize the bursal types observed among these families using the terminology of Mossman and Duke (1973). A partial bursal type with a laterally recurved oviduct and a medium to large per¬ itoneal opening was found in Mormoopidae, Phyllostomus- group, Brachyphyl 1 inae, and Glossophaginae (exclusive ol Anoura and Lonchophylla ; see below). As a variation, paitial bui- sae with a medially recurved oviduct and a medium to large slit- like peritoneal opening were found in the Macrotus -group, Des- modus, and Anoura. On the other hand, a complete bursa with a medially recurved oviduct and a minute poielike oi small slitlike opening was noted in Lonchophylla , Carolliinae, and Stenoder- minae. Noctilio also possessed a complete bursa, but there the oviduct wrapped around the cranial end of the ovary. The ovarian ligament extends from the ovary to an attachment at the junction of the oviduct and uterus. Comparative and ontogenetic studies have shown that this arrangement is a rather constant feature among eutherian mammals (Mossman, 1977). In the present study, this attachment was observed in all phyllo- 30 OCCASIONAL PAPERS MUSEUM TEXAS TECH UNIVERSITY stomoids except the Carolliinae and Stenoderminae (Fig. 15A). In these phyllostomid subfamilies the ovarian ligament does not at¬ tach in this manner, but is attached to the lateral (mesometrial) border of the uterus (Fig. 15B). This arrangement is quite inde¬ pendent of the mesenteries that generally suspend the reproductive organs. This modified site of ligamentous attachment is an apparently unique feature among mammals and therefore is con¬ sidered to be a synapomorphy of these two subfamilies. Discussion Histomorphological features of the uterus, oviducts, and ovaries in the New World bat families Noctilionidae, Mormoopidae, and Phyllostomidae illustrate a pattern of synapomorphy suggesting that phyllostomoid bats share a common evolutionary history. It is striking that extensive evolution of uterine morphology has occurred in these closely related families, compared to the conser¬ vatism found in most eutherian orders (Robin, 1881; Wood Jones, 1917; Matthews, 1941; Mossman, 1977). Comparative anatomists and embryologists have generally accepted a “fusion hypothesis’’ for the evolution of uterine morphology. This hypothesis is based on morphological and ontogenetic data viewed from a framework of out-group comparison. The present study has documented his¬ tomorphological details of the female reproductive tract in 29 genera and 36 species of phyllostomoid bats. Derived character states were hypothesized using out-group comparison. Phyloge¬ netic relationships based on a cladistical analysis of the data pre¬ sented in this paper are discussed by Hood and Smith (1982). Wimsatt (1975, 1979) and Mossman (1977) have discussed at length some features of reproductive biology that apparently are correlated with uterine morphology. The most consistent correla¬ tion is found in litter size; mammals with short bicornuate and simplex uteri carry only one or a few young. However, bats represent a major exception to this correlation. The majority of chiropteran species, including those with duplex and long bicor¬ nuate uteri, produce and carry but a single fetus (cases of twin¬ ning are known for several families). Available data on noctili- onids, mormoopids, and phyllostomids suggest that these three families are generally monovular and monotocous (Anderson and Wimsatt, 1963; Rasweiler, 1977; Bleier, 1979; Wilson, 1979). It seems clear, then, that the diversification of uterine morphology in phyllostomoid bats, and in the order Chiroptera as a whole, is not simply explained by adaptation towards small litter size. HOOD AND SMITH— HISTOMORPHOLOfiY 31 PRIMITIVE OVARY AND LIGAMENT ATTACHMENT TO LATERAL WALL Fig. 15. — Top : Diagram to illustrate the ovarian ligament character: A. normal attachment between ovary and external entry of oviduct, as found in most euther- ian mammals: B, modified attachment site, as found in carolliines and stenoder- mines. Bottom, Frontal section of the uterus, oviduct, and ovaries of I'ampyrops helleri. The ovarian ligament (ol) extends from the ovary to an attachment site on the lateral (mesometrial) border of the uterus as in B. above. 10X. 32 OCCASIONAL PAPERS MUSEUM TEXAS TECH UNIVERSITY Reproductive Asymmetry and Unilateral Reactions Anatomical and physiological asymmetry is not known to be a major reproductive feature in eutherian mammals. However, in bats asymmetry dominates the reproductive strategies of several families (Wimsatt, 1979). Within phyllostomoid bats, mormoopids and the Macrotus-g roup are markedly asymmetrical (with right- side dominance). Details of mormoopid reproduction are virtually unknown and need to be examined. In the two Pteronotus parnel- ln that had early-implanted blastocysts, implantation occurred in the right horn and the corpus luteum was found in the right ovary. In contrast, a number of studies have been conducted on asymmetry in Macrotus cahfornicus , which have shown that only the right ovary ovulates and the blastocyst always implants in the right uterine horn (Bradshaw, 1962; Bodley, 1974; Bleier, 1975). However, Bleier and Ehteshami (1981) demonstrated that when the right ovary is surgically removed, the left ovary can ovulate with subsequent development of early-implanted blastocysts in the left horn. These data suggest that expression of ovarian capacit¬ ance is complex and may be controlled by a number of factors. In the present study, the phyllostomine genera Micronycteris and Trachops have uterine morphologies similar to Macrotus. How¬ ever, none of these specimens were preovulatory or pregnant; therefore, details of the reproductive cycle are unknown. Unilateral oviductal and uterine reactions are known to occur in Noctilio and several phyllostomid genera (Rasweiler, 1978; 1979a). However, unilateral reactions are not unique to those fam¬ ilies, but have been recorded in several species of Pteropodidae and Emballonuridae (Marshall, 1953; Gopalakrishna and Murthy, 1960; Gopalakrishna and Karim, 1971). Rasweiler (1978, 1979a) has hypothesized that local veno-arterial pathways mediate these reactions and that unilateral oviductal reactions are important in the prolonged oviductal development of preimplanted blastocysts. We observed unilateral oviductal reactions in our specimens of Noctilio, Pteronotus parnellii (but not in other mormoopids), and in several phyllostomids. Local uterine-ovarian vascular systems were observed histologically in all noctilionid and mormoopid taxa examined. The function of these remains unverified. Further studies on reproductive physiology in phyllostomoid bats would certainly benefit our general understanding of reproductive asymmetry in bats. HOOD AND SMITH— HISTOMORPHOLOGV 33 Implantation The process of blastocyst implantation has been reviewed by Wimsatt (1975) and discussed by Rasweiler (1979a). Sites of implantation are quite variable in bats. Initial implantation may occur anywhere in the gestational uterus of many taxa, although some bats have a restricted site of implantation at the cranial end of the uterine cornua (Rasweiler, 1979a). Among bicornuate phyl- lostomoids, blastocysts of Noctilio initially implant at the cranial end of the uterine cornua. In simplex forms, the intramural uter¬ ine cornua (IUCs) are further restricted sites. We confirmed these observations in our specimens of Noctilio and several phyllostom- ids and newly documented the function of IUCs in Phyllostomus and Anoura. On the basis of our histological observations (hyper¬ trophied endometrium), IUCs can serve as primary sites of implantation in glossophagines, brachyphyllines, and carolliines. In stenodermines (which lack IUCs), blastocysts implant at the extreme fundic end of the common uterine lumen. Orientation of the embryonic mass of the blastocyst at initial implantation is extremely variable in bats. In Macrotus, Glosso- phaga, and Carollia it is oriented towards the uterotubal junction (Rasweiler, 1977a; Luckett, 1980). We confirmed this and noted a similar orientation in several other simplex phyllostomid bats, including Phyllostomus , Anoura, and Ariteus. Blastocyst orienta¬ tion has not been recorded in any mormoopid and in our material (two specimens), orientation of the mass could not be determined. The evolutionary significance of implantation and blastocyst orientation is not entirely clear; future studies on mormoopids and Macrotus- group phyllostomids are needed to clarify the gen¬ eral nature of these phenomena in phyllostomoid bats. Implications of Reproductive II istomor phology in I hyroptera After the present study was completed, Wimsatt and Enders (1980) published a description of the uterus and placenta of 7 hy¬ roptera tricolor (family Thyropteridae). They showed that Thy- roptera shares derived uterine and placental features with noctili- onids, mormoopids, and phyllostomids. From their account, it is dear that the uterus of Thyroptera is markedly fused externally, but has retained a relatively primitive internal uterine anatomy. Compared to phyllostomoid bats, external and internal uterine anatomy in Thyroptera is generally like noctilionids, although it appears that the thyropteran uterus may be somewhat more 34 OCCASIONAL PAPERS MUSEUM TEXAS TECH UNIVERSITY derived than that described for Noctiho. In any event, we concur with Wimsatt and Enders (1980) that Thyroptera shares the synapomorphy — external uterine fusion fused — with phyllostom- oids. The uterotubal junction of the thyropteran oviduct was noted by Wimsatt and Enders (1980) as being simple. In the present study, this feature was considered a synapomorphy of the super¬ family Phyllostomoidea. Although Wimsatt and Enders (1980) did not detail oviductal histomorphology, one of their photomicro¬ graphs (233: fig. 4) shows the oviduct to possess mucosal folds in the intramural junctura, an arrangement similar to that found in noctilionids and mormoopids. These observations support the inclusion of thyropterids in a monophyletic group including noc¬ tilionids, mormoopids, and phyllostomids. Acknowledgments This study was conducted by the senior author in partial fulfillment of the requirements for the M.A. degree at California State University, Fullerton. We gratefully acknowledge Ken E. Stager, Hugh H. Genoways, Mike Daniels, and Mike W. Haiduk for collecting some of the specimens used in this study. Donald R. Patten and Robert J. Baker kindly allowed us to dissect reproductive tracts from specimens housed at the Los Angeles County Museum of Natural History and The Museum, Texas Tech University, respectively. We thank Robert J. Baker, C. Eugene Jones, and William Presch for critically reviewing various drafts of this paper. Funds to defray costs of this research were provided by a Sigma Xi Student Grant-in-Aid of Research (to CSH), the Department of Biological Sciences, Cali¬ fornia State University, Fullerton, and the Departmental Associations Council at California State University, Fullerton. Collection of specimens by H. Genoways was supported by the M. Graham Netting Fund. Special thanks are extended to Mrs. Reese Taylor who supported field expeditions to Papua New Guinea in the summers of 1979 and 1981. Material collected on those projects added representa¬ tives of several Old World families used for out-group comparison. Finally, we are grateful to Shirley Neunaber for typing the manuscript. Literature Cited Anderson, D. H. 1928. Comparative anatomy of the tubo-uterine junction. His¬ tology and physiology in the sow. Amer. J. Anat., 42:255-305. Anderson, J. W., and W. A. Wimsatt. 1963. Placentation and fetal membranes of the Central American noctilionid bat, Noctilio labialis minor. Amer. J. Anat., 112:181-202. Baker, R. J. 1979. Karyology. Pp. 107-156, in Biology of bats of the New World family Phyllostomatidae. Part III. (R. J. Baker, J. K. Jones, Jr., and D. C. Carter, eds.). Spec. Publ. Mus. Texas Tech llniv., 16:1-441. Baker, R. J., and R. A. Bass. 1979. Evolutionary relationships of the Brachy- phyllinae to the glossophagine genera Glossophaga and Monophyl- lus. J. Mamm., 60:364-372. HOOD AND SMITH— HISTOMORPHOLOGY 35 Baker, R. J., A. Bass, and M. A. Johnson. 1979. Evolutionary implications of chromosomal homology in four genera of stenodermine bats (Phyllosto- matidae: Chiroptera). Evolution, 33:220-226. Bhatnagar, K. P. 1980. The chiropteran vomeronasal organ: its relevance to the phylogeny of bats. Pp. 289-315, in Proceedings Fifth International Bat Research Conference (D. E. Wilson and A. L. Gardner, eds.). Texas Tech Univ. Press, Lubbock, 434 pp. Bhatnagar, K. P., and F. C. Fallen. 1974. Morphology of the nasal cavities and associated structures in Artibeus jamaicensis and Myotis lucifugus. Amer. J. Anat., 139:167-190. Bleier, W. J. 1975. Early embryology and implantation in the California leaf¬ nosed bat, Macrotus cahfornicus. Anat. Rec., 182:237-254. - . 1979. Embryology. Pp. 379-386, in Biology of bats of the New World family Phyllostomatidae. Part III (R. J. Baker, J. K. Jones, Jr., and D. C. Carter, eds.). Spec. Publ. Mus. Texas Tech Univ., 16:1-441. Bleier, W. J., and M. Ehteshami. 1981. Ovulation following unilateral ovari¬ ectomy in the California leaf-nosed bat (Macrotus cahfornicus). J. Reprod. Fert., 63:181-183. Bodley, H. D. 1974. Ultrastructural development of the chorioallantoic placen¬ tal barrier in the bat Macrotus waterhousii. Anat. Rec., 180:351-368. Bonilla, H. de, and J. J. Rasweiler, iv. 1974. Breeding activity, preimplanta¬ tion development, and oviduct histology in the short-tailed fruit bat, Carollia, in captivity. Anat. Rec., 179:385-404. Bradshaw, G. V. R. 1962. Reproductive cycle of the California leaf-nosed bat, Macrotus cahfornicus. Science, 136:645-646. Corbet, G. B., and J. E. Hill. 1980. A world list of mammalian species. Brit¬ ish Museum (Natural History), Comstock Publ. Assoc. Cornell Univ. Press, London and Ithaca, New York, 226 pp. Edgar, D. G., and S. A. Asdell. 1960. The valve-like action of the utero tubal junction of the ewe. J. Endocrin., 21:315-320. Fleming, T. H. 1971. Artibeus jamaicensis: delayed embryonic development in a neotropical bat. Science, 171:402-404. Forman, G. L., R. J. Baker, and J. D. Gerber. 1968. Comments on the syste¬ matic status of vampire bats (family Desmodontidae). Syst. Zool., 17:417- 425. Gopalakrishna, A., and K. B. Karim. 1971. Localized progestational endome¬ trial reaction in the uterus of the Indian fruit bat. Rousettus leschenaulti (Desmaret). Current Science, 40:490-491. Gopalakrishna, A., and K. V. R. Murthy. 1960. Utero-ovarian junction in two species of bats. Bull. Zool. Soc. College of Science, Nagpur, 3:19-22. Graham C. E. 1973. Functional microanatomy of the primate uterine cer¬ vix. Pp. 1-24, in Handbook of Physiology, Section 7: Endocrinology, Vol. II. Female Reproductive System. Part II (R O. Greep and E. B. Ast- wood. eds.). Williams and Wilkins, Baltimore, 375 pp. Haeez, E. S. E. 1973a. The comparative anatomy of the mammalian cer¬ vix. Pp. 23-56, in The biology of the cervix (R. J. Blandau and K. Moghissi, eds.). Univ. Chicago Press, Chicago, 450 pp. - . 19736. Anatomy and physiology of the mammalian uterotubal junc¬ tion. Pp. 87-95, in Handbook of Physiology, Section 7: Endocrinology, Vol. II. Female reproductive system, Part 2 (R. O. Greep and E. B Ast- wood, eds.). Williams and Wilkins, Baltimore, 375 pp. 36 OCCASIONAL PAPERS MUSEUM TEXAS TECH UNIVERSITY Hafez, E. S. E., and D. L. Black. 1969. The mammalian uterotubal junc¬ tion. Pp. 85-126, in The mammalian oviduct (E. S. E. Hafez and R. J. Blandau, eds.). Univ. Chicago Press, Chicago, 546 pp. Hafez, E. S. E., and S. Jaszczak. 1972. Comparative anatomy and histology of the cervix uteri in non-human primates. Primates, 13:297-314. Hamlett, G. W. D. 1935. Notes on the embryology of a phyllostomid bat. Amer. J. Anat., 56:327-353. Handley, C. O., Jr. 1980. Inconsistencies in formation of family-group and subfamily-group names in Chiroptera. Pp. 9-13, in Proceedings Fifth International Bat Research Conference (D. E. Wilson and A. L. Gardner, eds.). Texas Tech Univ. Press, Lubbock, 434 pp. Harrison, R. J., and B. J. Weir. 1977. Structure of the mammalian ovary. Pp. 113-217, in The ovary. 2nd ed., Vol. I. General aspects (Lord Zuckerman, and B. J. Weir, eds.). Academic Press, New York, 517 pp. Hennig, W. 1966. Phylogenetic systematics (trans. D. D. Davis and R. Zan- gerl). Univ. Illinois Press, Urbana, 263 pp. Hood, C. S., and J. D. Smith. 1982. Cladistical analysis of female reproductive histomorphology in phyllostomatoid bats. Syst. Zook, 31:241-251. Humason, G. L. 1972. Animal tissue techniques. Third edition. W. H. Freeman and Co., San Francisco, 641 pp. Kanagawa, H., and E. S. E. Hafez. 1973. Morphology of cervix uteri of Roden- tia, Carnivora and Artiodacty la. Acta Anatomica, 84:1 18-128. Karim, K. B. 1975. Tubo-uterine junction in two species of Indian bats. Cur¬ rent Science, 44:589-590. Jones, J. K., Jr., and D. C. Carter. 1976. Annotated checklist, with keys to subfamilies and genera. Pp. 7-38, in Biology of bats of the New World Family Phyllostomatidae. Part I. (R. J. Baker, J. K. Jones, Jr., and D. C. Carter, eds.). Spec. Publ. Mus. Texas Tech Univ., 10:1-218. Lee, F. C. 1928. The tubo-uterine junction in various mammals. Bull. Johns Hopkins Hosp., 42:335-357. Lisa, J. R., J. D. Giola, and I. C. Rubin. 1954. Observations in the interstitial portion of the fallopian tube. Surgery, Gyn., Obst., 99:159-169. Luckf.tt, W. P. 1980. The use of fetal membrane data in assessing chiropteran phylogeny. Pp. 245-265, in Proceedings Fifth International Bat Research Conference (D. E. Wilson and A. L. Gardner, eds.). Texas Tech Elniv. Press, Lubbock, 434 pp. Machado-Allison, C. E. 1967. The systematic position of the bats Desmodus and Chilonycteris, based on host-parasite relationships (Mammalia: Chi¬ roptera). Proc. Biol. Soc. Washington, 80:223-226. Marshall, A. J. 1953. The unilateral endometrial reaction in the giant fruit bat (P ter opus giganteus Brunnich). J. Endocrinol., 9:42-44. Matthews, L. H. 1941. Notes on the genitalia and reproduction of some Afri¬ can bats. Proc. Zool. Soc., London, ser. B, 1 1 1:289-346. Mori, T., and T. A. Uchida. 1980. Sperm storage in the reproductive tract of the female Japanese Long-fingered bat, Miniopterus schreibersii fuligino- sus. J. Reprod. Fert., 58:429-433. Mossman, H. W. 1977. Comparative anatomy. Pp. 19-34, in The biology of the uterus (R. M. Wynn, ed.). 2nd. ed., Plenum Press, New York, 748 pp. Mossman, H. W., and K. L. Duke. 1973. Comparative morphology of the mammalian ovary. Univ. Wisconsin Press, Madison, 461 pp. HOOD AND SMITH— HISTOMORPHOLOGV 37 Nilsson, O., and S. Reinius. 1969. Light and electron microscopic structure ol the oviduct. Pp. 57-83, in The mammalian oviduct (E. S. E. Hafez and R. J. Blandau, eds.). Univ. Chicago Press, Chicago, 546 pp. Patton, J. C., and R. J. Baker. 1978. Chromosomal homology and evolution of phyllostomatoid bats. Syst. Zool., 27:449-462. Quintero, E., and J. J. Rasweiler, iv. 1974. Ovulation and early embryonic development in the captive vampire bat, Desmodus rotundus. J. Reprod. Pert., 41:265-273. Rasweiler, J. J., iv. 1972. Reproduction in the long-tongued bat, Glossophaga soricina. I. Preimplantation development and histology of the ovi¬ duct. J. Reprod. Pert., 3 1 :249-262. - . 1974. Reproduction in the long-tongued bat, Glossophaga soricina. II. Implantation and early embryonic development. Amer. J. Anal., 139:1- 36. - . 1977. Preimplantation development, fate of zona pellucida, and observa¬ tions on the glycogen-rich oviduct of the little bulldog bat, Noctilio albi- ventris. Amer. J. Anat., 150:269-300. - . 1978. Unilateral oviductal and uterine reactions in the little bulldog bat, Noctilio albiventris. Biol. Reprod., 19:467-492. - . 1979a. Early embryonic development and implantation in bats. J. Reprod. Fert., 56:403-416. - . 19795. Differential transport of embryos and degenerating ova by the oviducts of the long-tongued bat, Glossophaga soricina. J. Reprod. Fert., 55:329-334. Robin, H. A. 1881. Recherches anatomiques sur les Mammiferes de l’ordre des Cheiropteres. Ann. Sci. Nat., ser. 6, Zool., 12:1-180. Smith, J. D. 1972. Svstematics of the chiropteran family Mormoopidae. Misc. Publ. Mus. Nat Hist., Univ. Kansas, 56:1-132. - . 1976. Chiropteran evolution. Pp. 49-69, in Biology of bats of the New World family Phyllostomatidae. Part I (R. J. Baker, J. K. Jones, Jr., and D. C. Carter, eds.). Spec. Publ. Mus. Texas Tech Univ., 10:1-218. - . 1980. Chiropteran phylogenetics: introduction. Pp. 233-244, in Pro¬ ceedings Fifth International Bat Research Conference (D. E. Wilson and A. L. Gardner, eds.). Texas Tec h Univ. Press, Lubbock, 434 pp. Smith, J. D., and G. Madkour. 1980. Penial morphology and the question of chiropteran phylogeny. Pp. 347-365, in Proceedings fifth International Bat Research Conference (D. E. Wilson and A. I.. Gardner, eds.). I exas Tech Univ. Press. Lubbock, 434 pp. Tamsitt, J. R., and I). Valdivieso. 1963. Reproductive cycle of the big fruit- eating bat, Artibeus lituratus Olfers. Nature, 198:104. - . 1965. Reproduction of the female big fruit-eating bat, Artibeus lituratus palmarum, in Columbia. Caribbean J. Sci., 5:157-166. Thompson, S. W. 1966. Selected histochemical and histopathologic al methods. Charles C. Thomas, Springfield. Illinois, 1639 pp. Walton, D. W., and G. W. Walton. 1968. Comparative osteology of the- pelvic and pectoral girdles of the Phyllostomatidae (Chiroptera: Mammalia). J. Grad. Res. Center, Southern Methodist Univ., 37:1-35. Watrous, L. E., and Q. D. Whf.ei.er. 1981. The out-group comparison method of character analysis. Syst. Zool., 30:1-1 1. Wilson, D. E. 1979. Reproductive patterns. Pp. 317-378, in Biology of bats of the New World family Phyllostomatidae. Part III (R. J. Baker, J. K. 38 OCCASIONAL PAPERS MUSEUM TEXAS TECH UNIVERSITY Jones, Jr., and D. C. Carter, eds.). Spec. Publ. Mus. Texas Tech Univ., 16:1-441. Wimsatt, W. A. 1954. The fetal membranes and placentation of the tropical American vampire bat, Desmodus rotundus murinus. Acta Anatomica, 21:285-341. - . 1975. Some comparative aspects of implantation. Biol. Reprod., 12:1- 40. - . 1979. Reproductive asymmetry and unilateral pregnancy in Chirop- tera. J. Reprod. Fert., 56:345-357. Wimsatt, W. A., and A. C. Enders. 1980. Structure and morphogenesis of the uterus, placenta, and paraplacental organs of the Neotropical Disc-winged bat Thyroptera tricolor spix (Microchirptera:Thyropteridae). Anier. J. Anat., 159:209-243. W imsatt, W. A., and H. Trapido. 1952. Reproduction and the female repro¬ ductive cycle in the tropical American vampire bats, Desmodus rotundus. Amer. J. Anat., 91:415-446. Wislocki, G. B., and D. W. Fawcett. 1941. The placentation of the Jamaican bat (Artibeus jamaicensis parvipies). Anat. Rec., 81:307-317. Wood Jones, F. 1917. The genitalia of the chiroptera. J. Anat. Physiol., Lon¬ don, 51:36-60. Addresses of authors: Department of Biological Sciences, California State Uni¬ versity, Fullerton 92634 and Section of Mammals, Natural History Museum of Los Angeles County, 900 Exposition Blvd., Los Angeles, California 90007. Present address of Hood: Department of Biological Sciences and The Museum, Texas Tech University , Lubbock 79409. Submitted 4 March 1982, accepted 1 September 1982. PUBLICATIONS OF THE MUSEUM TEXAS TECH UNIVERSITY Three publications of The Museum of Texas Tech Univer¬ sity are issued under the auspices of the Dean of the Gradu¬ ate School and Director of Academic Publications, and in cooperation with the International Center for Arid and Semi- Arid Land Studies. Short research studies are published as Occasional Papers whereas longer contributions appear as Special Publications. Papers of practical application to col¬ lection management and museum operations are issued in the Museology series. All are numbered separately and pub¬ lished on an irregular basis. 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ISSN 0149-175X Texas Tech Press Lubbock, Texas 79409 OCCASIONAL PAPERS THE MUSEUM TEXAS TECH UNIVERSITY NUMBER 87 7 OCTOBER 1983 TYPE SPECIMENS OF MAMMALS IN THE COLLECTION OF THE INSTITUTE OF BIOLOGY, NATIONAL UNIVERSITY OF MEXICO Guillermina Urbano Vidales and Oscar Sanchez-Herrera The mammal collection of the Institute of Biology was founded in 1945 by Dr. Bernardo Villa-Ramirez and has been growing steadily since that time, especially through the cooperation of a number of staff scientists. As of October 1982, the collection con¬ tained 19,939 specimens — 17,394 skins accompanied by skulls, 2247 individuals in alcohol, and 298 complete skeletons. These specimens represent 356 of the mammalian species occur¬ ring in Mexico, based on published checklists such as those of Jones et al. (1977) and Hall (1981). All mammalian orders known to occur in Mexico are present in the collection; Rodentia and Chiroptera are the orders best represented, which is not surpris¬ ing, for rodents and bats together account for almost 75 per cent of the terrestrial species of mammals known from the country. The collection also houses several type specimens, some of which (the bats) were reported on previously by Alvarez (1966). The present paper is intended to provide a complete and updated list of type materials in the Institute of Biology. Twenty-six type specimens exist, which relate to 15 taxa, as described below. Insectivora Notiosorex ( Xenosorex ) phillipsii Schaldach 1966. Saugertierkund. Mitteil., 14:289, October.