Proechimys setosus ([Desmarest])
General characters.—Size medium; tail approximately same length as head and body; aristiforms moderately wide; feet rather large; ears of medium size; color on upper parts and sides sepia gradually changing to Ochraceous-Tawny; few differentiated, light-colored aristiforms present on outer thighs and rump; under surface of body and inner sides of legs white; tail with white tip and conspicuous, white pencil; feet white dorsally; skull short and smooth, somewhat flattened in interorbital region; jugals narrow dorso-ventrally; incisive foramen moderately long and notably narrow; vomerine sheath complete and slender; postorbital process of zygoma spinelike and involving mostly jugal; premolars usually with two counterfolds; molars with only one counterfold, rarely two in M1 or in M3.
Remarks.—The specimens available are undoubtedly faded and, therefore, the colors mentioned above for the upper parts and sides may not correspond to the colors of unfaded pelages. [Desmarest] (1817:59) describes the color of setosus as similar to that of the "Echimys de Cayenne" (Proechimys guyannensis) but being more "rousse." Is. [Geoffroy] Saint-Hilaire (1840:52) describes the same animal as being "d'un brun roussâtre" on the upper parts.
The Proechimys from Lagoa Santa, Minas Gerais, "Echimys" elegans [Lund], is certainly related to P. iheringi as well as to P. albispinus. From P. iheringi, elegans differs in having a smaller skull with shorter rostrum, narrower incisive foramen, and orthodont incisors. On the other hand the restricted distribution of the aristiforms in the pelage and the white, penicillate tail are points of resemblance to iheringi. From P. albispinus, elegans differs in having a less spinous pelage and longer tail with white pencil instead of a brown pencil. The skulls, however, are similar, except for the fact that elegans does not have proodont incisors as albispinus sometimes does. [Thomas] (1921:141) states, after describing the skull of the type of setosus, that "Specimens corresponding to this animal have been obtained at Lagoa Santa, Minas, by [Lund] and others, and at Bahia." [Thomas], however, would not have referred to specimens from "Bahia" as being comparable to elegans had they not been different from albispinus which he discussed in the same paper. Also, he would not have confused "specimens comparable to elegans" with a subspecies of P. iheringi (P. i. denigratus, from southern Bahia) which has opisthodont instead of orthodont incisors. Since French collectors sent material to Europe at the beginning of the 19th century from (southern?) Bahia, possibly setosus came from there.
In the collection of the American Museum of Natural History there is one specimen (AMNH no. 16140) of Proechimys, included in the so-called Maximilian Collection. The characters of this specimen agree closely with those of the specimens from Lagoa Santa. The locality of capture of specimen no. 16140 is unknown, but it is reasonable to assume that Prince Maximilian zu [Wied] obtained it somewhere along his route of travel through southeastern Bahia. [Wied] (1826:445) mentions "L[oncheres]. myosuros Licht." as "am Parahyba, am Peruhype und Belmonte," which greatly increases the possibility of its having come from southern Bahia. The close similarity to elegans of [Wied's] specimen indicates that the locality of capture possibly was in the region of the less humid, low escarpments of southern Bahia.
My conclusion is that [Wied's] specimen corresponds closely to setosus and, tentatively, I identify it as such. "Echimys elegans," due to the relationships mentioned above is here considered to be a subspecies of setosus.
Among the species described in earlier times, and whose identity was never ascertained, "Echinomys" fuliginosus [Wagner] seems to be synonymous with setosus. [Wagner] describes the animal as having a tail "apicis versus pilis albidis vestita" and the figure of the cheekteeth (1844, pl. 239 D) shows a typical trilaminate condition which occurs commonly in elegans. Moreover, the tail of fuliginosus is only 9 per cent shorter than the head and body and the aristiforms of this subspecies are moderately wide.
Proechimys setosus setosus ([Desmarest])
Echimys setosus [Desmarest] ([Geoffroy's] MS), 1817, Nouv. Dict. Hist. Nat. nouv. ed., 10:59 (orig. descr.); Is. [Geoffroy] Saint-Hilaire, 1838, Comptes Rendus Acad. Sci., Paris, 6(26):886; Is. [Geoffroy] Saint-Hilaire, 1840, Mag. Zool., Paris, (ser. 2, année 2):12, 33, 52; [Allen], 1899, Bull. Amer. Mus. Nat. Hist., 12(20):257, 261.
Echimys cayennensis Pictet, 1841, Mém. Soc. phys. Hist. Nat., Genève, 9:145; Waterhouse, 1848, Nat. Hist. Mammalia, 2:334.