The purpose of this study was to determine the kinds, population, distribution, and general habits of the mammals of the Lynndyl sand dune area. Only one article concerning the dunes was found, but several have been written on other dunes; however, none was found concerning mammals. Two quantitative studies, plot and transect trappings, were made and general observations were taken within the study area. Three types of plots; Russian thistle, juniper, and baren moving dunes; were trapped and revealed the following species: Dipodomys ordii, Peromyscus maniculatus, Reithrodontomys megalotis, Onychomys leucogaster, and Neotoma lepida. The most numerous animal in all plots was Dipodomys ordii followed in all cases by Peromyscus maniculatus. It was found that D. ordii prefer open sand; P. maniculatus, sage and R. megalotis, dense cover. The greatest activity and highest number of catch was in the summer. The major cause for the higher number of catch was the larger number of immature animals cught, but food availability may have had some effect. More than one breeding season, or at least a fluctuatin breeding season, apparently occurs in both predominant species, but further study on this point is recommended. The weights of the specimens were taken. This aided in determining the age of specimens and their breeding activities. Other mammals in the area are: Dipodomys microps, Lepus californicus, Erethizon dorsatum, Odocoileus hemoinus, Taxidea taxus, Vulpes macrotis, and Canis latrans.

Telemetric observations were conducted on a pair of Sharp-Shinned Hawks (Accipiter striatus velox) nesting in Spanish Fork Canyon, Utah in 1972. The movements of both adults were monitored from the time their eggs hatched in late June until they left the study area in early August, fourty-two days later. A transmitter was also attached to one of the young at the time of fledging. The adult's main hunting area was a single plant community located 1600 meters from the nest. The male performed the majority of the foraging while the female spent the greatest part of her time at the nest. Information on sixty-one Sharp-shinned Hawk nests in Utah was analyzed. The typical nest site was determined as being a small stand of coniferous trees present in a deciduous tree community. Sharp-shinned Hawks in southern Utah began nesting activities up to twenty days before the same species 350 miles away in northern Utah. Thirty-four nests averaged a clutch size of 4.3 eggs.

Five publications and one manuscript concerning the taxonomic studies of trombiculid mites are submitted. Publications include a revision of the North American genus Comatacarus Ewing, the erection of the following genera by Brennan and Reed: Loomisia, Atelepalme, Phalcophila, and Nycterinastes. Discussions of the genera Aitkenius Brennan and Polylopadium Brennan and Jones are also included. The subfamily Leeuwenhoekinae is reviewed on the basis of neo-tropical representatives (unpublished manuscript). The genus Odontacarus comprises 66% of the chiggers examined, and 82% of these were identified as O. tubercularis (Brennan). Odontacarus fieldi Brennan and Jones and O. cayolargoensis Brennan are synonomized under O. tubercularis (Brennan), 1952. The following genera are redescribed: Albeckia Vercammen-Grandjean and Watkins, Leeuwenhoekia Oudemans, Odontacarus Ewing, Sasacarus Brennan and Jones, Wagenaaria Brennan, and Whartonia Ewing. Eight species and subspecies of Odontacarus, one species of Sasacarus, and one species of Whartonia are described as new.

The anterior myology of Crotaphytus wislizeni and C. collaris is described in detail and a statistical analysis is made of the differences in the relative bone sizes, and the number of eggs per clutch, as well as other taxonomic characters previously applied to these species. The significant differences found with respect to the shape of the skull, that of the body, and the character of the hyoid are correlated with muscular development and habits of the two species. The descriptive material is accompanied by detailed myological and osteological illustrations of C. wislizeni. Comparative notes are made on C. reticulatus which is found to be intermediate between these species with respect to its myology. The results of this study indicate that Gambelia and Crotaphytus are synonymous.

It is the purpose of this study to make gross and histological comparisons of the various segments of the intestinal tracts of the jack rabbit and the pika. The two animals used for this study were the desert jack rabbit (Lepus Californicus deserticola Mearns), and the pika (Ochotona princepts uinta Hollister). The jack rabbits were found only in the desert valleys and low foothills in the areas studied. These areas are typically open bush or sage brush types of communities. The pikas were restricted to certain high rockslides in this region. These areas are described more completely in the section on Methods and Materials. This study is limited to a comparison of the gross and microscopic anatomy of the idgestive tube in these two animals.

This paper presents the results of a taxonomic stury of mites of the genus Haemolaelaps collected from small mammals of 8 political subdivisions of the northwest portion of the Ethiopian Biogeographical Region. Specimens taken from 2,863 small mammals from a wide variety of habitats and localities were examined. The Haemolaelaps fauna includes 23 species, 10 of which are described as new: H. bellasoma, H. caurinus, H. chaetospinicus, H. crocidura, H. desmodilliscus, He. ebsi, H. malachela, H. parahirsti, H. sikapusi and H. taterakempi. Numerical taxonomic and multicariate analyses were used to assess variation and clustering. A key for identification of females is given. Illustrations and diagnostic characters are given for the females of the new species. Collection data and discussions of host-parasite associations and specificity are provided.

A total of over 5000 mite specimens representing 49 species was studied and evaluated. The most frequently encountered species was Ornithonyssus bacoti. Based on these specimens, a brief review of the family Macronyssidae in Venezuela is presented. Included are brief notes as to medical importance and host relationships; also a key to the genera of Venezuelan Macronyssidae and a host-parasite list are included. Reprints of two papers and the manuscript of a third are included as part of the dissertation requirements. Contained in these are descriptions of three new genera (Argitis, Lepidodorsum, and Nycteronyssus) and four new species (Acanthonyssus proechimys, Argitis oryzomys, Lepidodorsum tiptoni, and Nycteronyssus desmodus.), all made from Venezuelan material.

How the eggs and larbae of the Utah amphibians differ from each other is the problem to be considered in this paper. Certain problems are yet to be answered. One problem is that the larvae of Rana pretiosa subsp. From utah fit the description of the Nevada form, Rana pretiosa luteiventris, as described by Thompson (1913) and not the description of Rana pretiosa pretiosa as set forth by Svihla (1935). Another problem is that the adults, tadpoles, and eggs of Rana pipiens brachycephala and Rana onca are strikingly similar. Rana fisheri of the Las Vegas Valley in nevada and Rana onca are rather similar. There are fourteen species of utah amphibians. Only twelve of these will be considered here as two species are comparatively rare and material was unobtainable for this study. Variations from previous descriptions of some of the eggs and tadpoles are noted therein. A description of the eggs and tadpoles of Rana onca, Bufo woodhousii microscaphus, Ambystoma tigrinum nebulosum, the eggs of Scaphiopus hammondii intermontanus and the tdpoles of Bufo boreas boreas are advanced for the first time.

This investigation examined the social structure of four species of small mammals (Perognathus parvus (Peale), Reithrodontomys megalotis (Baird), Peromyscus maniculatus (Wagner), and Dipodomys ordi (Woodhouse) at the National Reactor Testing Station (NRTS) in Idaho. An understanding of the social structure provides ecological clues concerning the integration of interactions, reproduction, distributions, densities, and diel activities for not only one animal and species, but for a complex of animals interacting with each other.

A life history field study of the widespread desert wood rat, Neotoma lepida lepida Thomas, was conducted periodically from August, 1959, to June, 1960, eight miles west of Jericho, Juab County, Utah. An estimation of the density of houses and population density of wood rats throughout the general region, accomplished by charted guadrats and a plotless quarter method, revealed an average densityof 4.9 houses of 3.1 adult wood rats per acre in a juniper-sagebrush community of the type frequently found throughout the area. Live-trapping within a well-wooded juniper-sagebrush community (twenty-four acre area) revealed twenty-seven wood rats captured sixty-eight times for a density of only 1.1 rats per acre. Each occupied house was usually inhabited by only one adult wood rat.