A Partial Description of the Tadpole of Rana areolata circulosa and Notes on the Natural History of the Race

Abstract

In 1939 one of us (Philip Smith) while enrolled at Southern Illinois Normal University at Carbondale, intensively pursued a field study of Rana areolata circulosa under the direction of Dr. Fred R. Cagle. Actual work on it, concentrated in the vicinity of Herrin, Illinois, began in 1938, and was continued through 1940. Unforeseen developments prevented completion of the project, although in 1942 Cagle published excerpts from the data then accuinulated. The notes recorded during the study are available at the present time, in addition to a small portion of thle preserved materials. Among the latter are five mature and transforming tadpoles, especially valuable since the larval stage of this species has never been described. With our description of the tadpoles, we include certain apparently novel materials from Smith's notes. Unfortunately all the small jars containing stomach contents and tadpoles at various stages of development were completely dry when reexamined in the summer of 1947 after a few years of storage. The material would have been a total loss had it not been possible to restore it partially by the technique described recently by Van Cleave and Ross (1947). In fact Dr. Van Cleave kindly treated the dried specimens for us. The tadpoles were rendered flexible enough to permit manipulation, although they remained shrunken in appearance. The mouth disks appear normal, but body proportions are unquestionably distorted; accordingly, while the description of the mouthparts may be considered more or iess accurate, the measurements are undoubtedly subject to correction on the basis of fresh material.