358 Air. 0. Thomas on the 



XLT. — The Geographical Races of the Woolly Opossum 

 ( Philander 'laniger). By Oldfield Thomas. 



(I'ublislied by permission of the Trustees of the British Museum.) 



The series now available of the Philander laniger group 

 covers fairly well the chief area over which these beautiful 

 animals are found — from Vera Cruz to Peru. Passing from 

 north to south, they seem to fall into the following geogra- 

 phical races : — 



S. Mexico Ph. I. aztecus, subsp. n. 



Guatemala Ph. l.feruidus, subsp. n. 



Costa Rica and Panama Ph. I. patiidus, Thus. 



Islands off Panama Coast Ph. I. nauticus, subsp. n. 



Western Colombia and N. Ecuador. . Ph. I. derbiamts, Waterh. (syn. 



pyrrkus, Thos-.), and pictus, 



subsp. n. 

 Santa Marta, Bogota, and Merida . . Ph. I. cicur, Bangs. 



"Western Ecuador Ph. I. guayanus, Thos. 



Eastern Ecuador Ph. l.jivaro, subsp. n. _ 



Peru Ph. I- omatus, Tschudi. 



The original " Micoure laineux " of Paraguay (Ph. I. 

 laniger) and that described by Wagner as Dide/phys ochropus 

 from the lower Rio Negro no doubt also represent distinct 

 races, but 1 have seen no specimens of either. 



It is not yet clear what is the relation of the beautifully 

 contrasted grey and red forms — such as aztecus and pictus — 

 to those more uniformly coloured. One of each occurs in 

 Western Colombia, though not in absolutely the same locality, 

 but elsewhere only a single form is found in each of the areas 

 mentioned above. It is remarkable how like aztecus and 

 pictus are to each other, while the region between them is 

 occupied by the more uniformly coloured jervidus and 

 pallidus. 



The possibility of making this study has hitherto been 

 delayed by the difficulty of allocating the name derbianus, 

 Waterhouse, 1841, based on a specimen of unknown locality 

 with characters that might belong to any of the races, from 

 Mexico to Peru. Now, however, thanks to the kindness of 

 the authorities of the Liverpool Museum, I have had the loan 

 of Waterhouse' s type, which I find to agree fairly closely 

 with the form of the Cauca Valley, my Ph. I. pyrrhus being 

 therefore a synonym of it. This same identification was 

 made — either by a clever guess or alter examination of the 

 t^pe—Py Dr. J. A. Allen in 1SJ04 *. 



* Bull. Am. Mus. N. II. xx. p. 57 (1004). 



