Amphibian Genus Research Articles

Chromosome Number Difference in the Amphibian Genus Bufo: The Bufo regularis Species Group

Chromosome Number Difference in the Amphibian Genus Bufo: The Bufo regularis Species Group

Bile pigment excretion in amphibia.

IN man and in other mammals, bilirubin is excreted in conjugated form, mainly as the glucuronide. Since in mammalian fœtal liver the enzymatic mechanism for glucuronide formation is poorly developed, reaching its full capacity only after birth, transient hyperbilirubinaemia is frequently observed during the neonatal period1. In the amphibian genus, Rana, hepatic glucuronide formation is absent in the larva, but present in the adult2. The larval forms undergo extra-uterine development and hence are readily accessible. These Amphibia would represent an excellent experimental model for studying various aspects of neonatal hyperbilirubinaemia, if it could be established that they, like mammals, excrete bilirubin as glucuronide. Therefore, we have examined amphibian bile pigment excretion to determine, first, whether in the adult Rana bilirubin is excreted as a glucuronide; secondly, whether metamorphosis is associated with qualitative or quantitative changes in pigment excretion; and thirdly, whether the excreted pigment is biliverdin, as has been postulated previously3, bilirubin, or another pigment.

Trematops Thomasi, a New Amphibian Species from the Permian of Oklahoma

The amphibian genus, Trematops Williston, has been represented until recently by a single specimen, a skull and associated skeleton from the Permian of Texas. The skull is unique among vertebrates in the presence of a median, unpaired opening that pierces the skull near its tip. The following description is of a skull from the Permian of Oklahoma that is similar to that from Texas in many details. However, the Oklahoma specimen shows the unpaired opening on the palate surface only. Another point of interest is the remarkably well preserved "turbinated" bone.

Broiliellus, a New Genus of Amphibians from the Permian of Texas

The material upon which this genus is based comprises two specimens, Nos. 684 and 685, University of Chicago, collected by Mr. Paul Miller on Timber Creek, Texas. Both specimens, when found, were almost completely inclosed in hard clay nodules. The matrix has been removed from the surface of the bones very cleanly, but no attempt has been made to separate any of them. The larger and more complete of the two specimens, No. 284, the holotype, includes the complete skull, but very slightly distorted, connected with the complete series of dorsal shields; the right humerus in position with the somewhat crushed scapula; the incomplete clavicular girdle; the incomplete left humerus and a part of the hand; the right femur, tibia, fibula, three tarsals, and two metatarsals. There is also a fragment of the pelvis. Specimen No. 285, of slightly smaller size, has the complete skull less compressed than that of the other specimen. It also is connected with the complete series of dorsal shields, and their corresponding vertebrae; also the clavicular girdle is in place; and an imperfect humerus. Only slight indications of the ribs are present in either specimen.

Restorations of Some American Permocarboniferous Amphibians and Reptiles

(WITH ILLUSTRATIONS BY THE AUTHOR) The drawings illustrating the present paper were made in the hopes thereby of learning more concerning the animals as living organisms. Depending exclusively upon dried and petrified bones, the paleontologist is apt to forget that his fossils were once parts of living, active beings. Nearly all the restorations are based upon practically complete skeletons preserved in the museums of the University of Chicago or Yale University, technical descriptions of which have been published in various places during the past few years. Their living restorations, except that of Eryops, are here attempted for the first time. I will not attempt to give any technical details of their structure here; my only desire is to place before the general student of geology something of what I see, after years of study of the fauna, in some of the animals that lived in Texas and New Mexico during the closing times of the Pennsylvanian and the early times of the Permian. The land vertebrate fauna of those times in America must have been very rich. More than forty distinct genera of amphibians and reptiles are represented in the collections of the University of Chicago, and the remains of at least a dozen more are preserved in the American Museum and at Yale University. It is the oldest fauna of reptiles known in the world, and by far the most comprehensive of the older amphibians known. The animals of the South African Karoo system are nearly all of later age, Upper Permian as distinguished from Lower Permian and Carboniferous, and they were, for the most part, more highly specialized and less primitive. And the light these animals of the American Permocarboniferous have thrown upon the evolution of the higher vertebrates is very great, though there is very much more to learn. The primitive

VII. Notes on the Mineral Seams round Airdrie and their Fossils

The organic remains found in the Coal-bearing or Carboniferous beds round Airdrie would lead us to infer that the strata were all laid down in fresh water. I have discovered only one place, 1 inch in thickness, between the Kiltongue and Virtuewell Coals, where truly marine fossils have been found. These were Aviculopecten papyraces and Orthoceratites. The fossils were shown to this Society (see page 342, vol. viii., T.G.S.G.). This is not the only marine bed found in the upper seams of Lanarkshire, similar beds being discovered by R. White, Skipsey, nearer Glasgow,* and at Dalmellington, Ayrshire, by Mr. John Smith; in Fifeshire, by Mr. Kirkby; and also in England. In the Airdrie beds we have animals represented from the class Annelida to the class Amphibia. We have no living representatives of several of these forms. Many of them never made their appearance in geological time after the Carboniferous period; some forms appear in other periods and disappear in geological time, while other forms appear in Carboniferous time and at the present day. The climate during the laying down of the Carboniferous beds around Airdrie must have been similar to that in many parts of Africa, for in the Palacecraig ironstone no fewer than five genera of Amphibians have been found which were new to science. Some forty-two years ago Mr. James Russell, of Chapelhall,† found the first of these. He took it up to London and showed it to Professor Huxley, who got the Government to give him, £150 This 250-word extract was created in the absence of an abstract

The Lophiomys

As the oft-repeated statement (which originated with M. Alphonse Milne-Edwards) that the roofed-in temporal fossa of the Lophiomys finds its parallel in certain reptiles alone reappears in the pages of Messrs. Cassell's excellent “Popular Natural History” (see NATURE, vol. xxi. p. 137), it is high time that it should be modified in accordance with more recent anatomical investigations, which show that two amphibian genera, Pelobates and Calyptocephalus, participate in this singular abnormality.