PROCEEDINGS OF THE CALIFORNIA ACADEMY OF SCIENCES Volume 50, No. 1 cles large and strongly protruding; (6) toe disks smaller than finger disks. The dorsalis Group. (1) terminal phalanx bluntly rounded to pointed; (2) tips of fingers blunt, without disks, or with small to moderate disks; (3) first finger slightly shorter, about as long as, or slightly longer than second; (4) digits proximal to disks about as deep as broad; (5) subarticular tubercles large, strongly protruding and frequently pointed; (6) finger disks smaller than to slightly larger than toe disks. History of the Collections of Philippine Species of the guentheri Group The data base for this revision of the Platymantis guentheri Group is the result of over a hundred years (1882-1996) of field sampling and observations by numerous workers. The accumulation of data before 1954 was very slow. It has accelerated since then. It is appropriate that readers understand some of the reasons for this, as well as the problems that limit the collection of field data even now. During the period from 1882 to 1954, the species of the guentheri Group, like those of the hazelae Group (Brown et al. 1997) were only rarely collected because of the sampling techniques typical of most field work in the Philippine Islands during that period. Taylor's extensive surveys on several islands during the period 1912-1 922 produced only a few examples of any species of these two species Groups. Cornufer (= Platymantis) guentheri was described on the basis of a single specimen from Dinagat Island (Boulenger 1882). This species was redescribed by Taylor (1920) based on two specimens from Bunawan, Agusan del Norte Province, Mindanao. He does not mention additional examples of this species in his later papers (1922a, 1922b, 1922c, and 1923). In the 1920 paper, however, he did recognize a second species of the guentheri Group, Cornufer worcesteri from Mt. Apo in Davao Province, Mindanao (Stejneger 1905). Taylor's surveys on several of the islands during the period 1912-1922 employed sampling techniques which exploited the fauna inhabiting the forest floor and low shrub and tree habitats, but not the more arboreal habitats of the species in the guentheri and hazelae Groups. During the period from 1922 until World War II little field work was undertaken. Thus at the time of Inger's (1954) monograph on the Philippine frogs, the samples of P. guentheri were still very limited: Philippines 2, Dinagat 1 (type of guentheri), Luzon 3, Polillo 4, Leyte 1 and Mindanao 8 (including the type of Cornufer worcesteri). In 1954 the senior authors (Brown and A. Alcala) began their Philippine heipetofaunal studies that have continued to the present time. A population of Platymantis guentheri on Negros Island was the first identified (Brown and Alcala 1957). Subsequently large samples from populations on both Bohol and Negros Islands were added to the data. This was the result of two factors: (1) the study of herpetofaunas of these two areas from a base at Silliman University for a period of more than a decade (1956-1972) and (2) the use of sampling techniques designed to exploit the arboreal microhabitats of amphibians, such as Platymantis and Philautus, as well as some genera of geckos and skinks. Other areas such as Dapitan Peak of the Malindang massif, Zamboanga Peninsula, and Mt. Hilong-hilong in northeastern Mindanao were surveyed during one or two expeditions to those rather remote regions using the same sampling techniques, but the samples were small (Alcala 1986). The large samples accumulated for Negros and Bohol did provide evidence of the presence of two species on Bohol (Brown and Alcala 1963) but only one species on Negros. It is also important for the reader to understand that there are difficulties which limit follow-up and repetition of some of these surveys. Extensive logging on both Negros and Bohol has greatly reduced the areas of forest normally occupied by these frogs. A brief survey of forest remnants on Cuernos de Negros, southern Negros in 1996 confirmed the continuing presence of a population of negrosensis in that area. Whether or not there is an extant population of either guentheri or rabor in the forest remnants on Bohol remains to be seen. We hope to be able to determine this within the year. A follow-up expedition to the Mt. Hilong-hilong area in northeastern Mindanao presents greater difficulties: (1) the lack of security in the region is a risk to personnel involved and (2) the survey would require a large commitment of men and resources. The recent modest samples of luzonensis and banahao from Mt. Banahao and Mt. Maquiling