Diagnosis.--A species of Isothrix with the following combinationof characters: long, lax fur without conspicuous supraorbital stripes, ablackish dorsal crest or mane, a uniformly haired tri-colored tail with theterminal 5 cm white, compact braincase, broad foramen magnum with distinctdorsal median notch, small auditory bullae, narrow triangle-shapedinfraorbital foramen, narrow palate, and well developed maxillary componentof septum in incisive foramina.
Fore- and hind-feet powerfully built with fleshy digits, four onthe manus and five on the pes, each bearing a curved claw 3-5 mm long. Thefirst interdigital pad of the manus is spherical in shape, the thenar andinterthenar pads subequal in size, slightly larger than interdigital pads2-4.
Skull compact, with long axis bowed, and neither rostrum norocciput produced (Fig. 4). Zygomatic arches moderately flared, with thesuperior jugal process distinct when viewed from above. Nasal bones shorterat midline than laterally. Lacrimal bone well developed. Interorbital regionbroad, expanded posteriorly and extending over orbits in flared, elevatedsupraorbital shelf. Frontal bones squared posteriorly at level of posteriorzygomatic root. Braincase not swollen and temporal fossa not deep. Nuchalcrest well developed and arched, running continuously from the paracondylarprocesses of the exocciptals. Supraocciptal with medial ridge overhanging theforamen magnum and forming the posteriormost extension of the skull.
In ventral aspect, cranial flexure is marked, with the foramenmagnum completely visible and bounded by the occiput. The incisive foraminaare short and narrow, flexed in the middle and bounded by elevated ridgesrunning onto the palate, forming on each side a marked fossa on the ventralmargins of the zygomatic inferior root. Palate narrow, ridged longitudinally,slightly widening posteriorly, where it is deeply incised by a V-shapedmesopterygoid fossa. Hamular processes of the pterygoids long and delicate,flaring over foramen lacerum and passing the anterior plane of the bullae.Foramina ovale positioned posterior and lateral to the pterygoid fossae.Bullae separated by a distance greater than the greatest palatal breadth andframed posteriorly and laterally by the mastoid. The holotype has a foramenmagnum measuring 7.2 mm in breadth, much broader than other similarly-agedand--sized Isothrix and 18% of CIL (not 11.5-13% as in a sample of I.bistriata). The supraoc-cipital overhangs the foramen magnum and has a medialnotch.
Comparisons.--The new species of Isothrix can be distinguishedfrom all congeners by its long, lax and saturate pelage. No other species hasa dorsal crest or mane of blackish hairs. I. bistriata and I. orinoci shareits distinctive coloration of the tail (albeit often without the white tip),while that of I. pagurus is monocolored and I. sinnamariensis sports a tailwith elongate curls distally. Cranially, it most closely resembles I.bistriata. Although comparisons are hampered by the lone subadult specimen,it is biometrically distinct from all (Table 2). The foramen magnum isrelatively broad (7.2 mm), proportionately broader than other species ofIsothrix, and its dorsal margin is notched. The bullae are small and rounded,not inflated as in other species; in I. barbarabrownae, the bullae areseparated by distinct gaps from the paraoccipital processes posteriorly andthe parapterygoid fossa anteriorly, so that it has the most pronounced middlelacerate foramen.
In 1961 Darling moved to the United States, first to work at the University of Kansas Medical Center Library in Kansas City, and then, from 1962 to 1968, in the History of Medicine Division of the National Library of Medicine, Bethesda, Maryland. There he catalogued the library's early modern books and compiled its Catalogue of Sixteenth Century Printed Books in the National Library of Medicine (Bethesda, Maryland, National Library of Medicine, 1967). While preparing this large and now famous work, he also found time to prepare an exhibit (with catalogue) on the career of the Renaissance humanist Conrad Gesner (1516-1565) and to publish the register which Gesner kept of humanist friends visiting him in Zurich (Gesnerus, 1965, 22, 134-159). During his stay in Bethesda, Durling also extended his research on Galen's fortuna backwards in time, selecting, [End Page 179] cataloguing, and adding nearly 600 microfilms of medieval manuscripts to the library's holdings.
Trained in classical philology, Durling's models were not the generalists of nineteenth-century Cambridge and Oxford, such as Richard C. Jebb and Friedrich Max Müller, but humanists of the sixteenth century, with whom he shared a passion for the quiddity of lexicography, bibliography, and textual study. In particular, Durling's career calls to mind that of Conrad Gesner, whose industry, commitment to Greekscholar ship, and international network of friends and colleagues Durling himself wrote eloquently about. Alas, as Gesner died prematurely before the last volume of his Historia Animalium was written, so too did Richard J. Durling leave his catalogus of Galenic books and manuscripts unfinished. However, his magnum opus was near enough to completion that we can hope to see it yet finished, thereby reaping the harvest of Durling's industry, mastery of Greek and Latin philology, and unparalleled knowledge of Galen's fortuna in the Middle Ages and Renaissance. 041b061a72