210 Mr. 0. Tliomas on some 



mainly by size. The largest, L. thomasi, Iliering, from the 

 island of Sa3 Sebastian, Sao Paulo, was originally described 

 as a Mesomys, because the type had no tail, but was later on 

 erroneously referred by its founder to L. nigrispina. It is, 

 however, much larger and differently coloured. The 

 smallest, L. dasi/thn'a;, Hensel, is represented by one of the 

 original typical skulls from Rio Grande do iixd, and two 

 dealers' specimens from the island of Santa Catherina. The 

 present intermediate species occurs in Parana and the main- 

 land of Santa Catherina. 



From all these three Wagner's L. nijjrispina would appear 

 to be distinguished by its sharply detined light underside, 

 with the fur light to the base, which is mentioned both in the 

 original description and in my notes on the type in Vienna. 

 In size it only equals, or but little exceeds, the smallest of 

 the above-mentioned species, L. dasytlirix. The type was 

 collected at Ypanema, Sao Ptiulo. 



Echimys laticeps, sp. n. 



In 1902 the British Museum received from Mr. W. Foster 

 topotypical examples from Paraguay of the rare Echimys 

 spinosus, Desm.*, and on their arrival I naturally compared 

 them with a specimen bearing the same specific name which 

 had been collected at Lagoa Santa, Minas Geraes, by Rein- 

 liardt, determined by Wmge fj and acquired by exchange 

 from the Copenhagen Museum. 



The two animals were obviously entirely distinct, but as 

 in his great work on the Mcimmals of Lagoa Santa, Dr.Winge 

 had referred to a '' Loncheres ladcejjs, Lund," which he stated 

 to be the same as E. spinosus, 1 let the matter rest, considering 

 laliceps available for the Lagoa Santa species. 



But now, on again referring to the genus, I find that Lund 

 appears J never to have described his '"'Loncheres laticeps,^' 

 which therefore was, and still is, a iiomen nudum, although it 

 has many times been referred to in synonymies. In ray 

 search for a description 1 have been materially assisted by 



* El espinoso, Azara. The names spinosus, Desm., 7-ufa, Licht., and 

 brachyurus, Wagn., were all originally based on Azara's Paraguayan 

 animal, whatever they were afterwards transferred to by other writers. 



t As " Mesomys " sjjijwsus. I follow Dr. Allen's admirable paper 

 clearing up the much embroiled nomenclature of the genera of this group 

 (Bull. Am. Mus. N. H. xii. p. 257, 189iJ). The real Mesomys was 

 identified by me in a later paper (Ann. & Mag. Nat. Hist. (7) xv. p. 590, 

 1905). 



X Dr. Winge has been good enough to confirm my belief iu the absence 

 of any description. 



