

MAMMALIA. 685 



hinder pentadactylous ; outer toe short both before and behind. 

 Tail long, annulate, thinly haired. 



Sp. Cercomys cunicularius F. Cuv. Mammif., Livr. 60, Nouv. Ann. du Mus. 

 I. 1832, pp. 449452, PL 18, fig. i (molar teeth), PI. 19, figs, i, * (cra- 

 nium), Hab. in Brasil. 



Loncheres ILLIG., Echimys GEOFFR. (Echinomys more correctly 



4 4 



WAGN.). Incisor teeth smooth ; molar -r -j, complex. Whiskers 



long, numerous. Spines almost always intermixed with hairs on 

 the back, lanceolate, flat, or concave above. Fore feet tetradacty- 

 lous, with thumb-wart unguiculate, hinder pentadactylous. Claws 

 short, compressed, incurved. Tail long, annulate, more or less 

 hairy. 



Compare on this genus of South American rodents ISID. GEOFFB. 

 SAINT-HILAIBE Notice sur les Rongeurs epineux in GUEBIN Magas. de ZooL 

 1840, Mammif. pp. i 57, PI. 20 29. 



Dactylomys ISID. GEOFFR. Fore feet tetradactylous. Two middle 

 toes of fore feet and three middle toes of hind feet much longer than 

 the lateral toes. Tail long, annulate, thinly haired except the base. 

 Spines none. (Each molar tooth composed of two parts divided 

 by a transverse groove; crown of upper molars divided into two 

 triangles, with the acute apex internal, emarginate externally, 

 crown of lower with first part triangular, incised internally, the 

 other part oval.) 



Sp. Echimys dactylinus DESMAB., Dactylomys typus ISID. GEOFFB. 1. 1. PL 

 20, DEVILLE in GUEBIN Revue et Magas. de Zool. 1852, pp. 354 357; 

 Dactylomys embtyonyx NATTEBEB, WAGN. 



Echinomys (IsiD. GEOFFR.), WAGN. Characters of the genus. 

 Ears elongate, acuminate. Tarsi elongate, narrow. Molar teeth 

 small, with crown rounded. Spines in adults, mostly mixed with 

 hair. 



Sp. Loncheres cayennensis (Fiscn.), Echimys cayennensis GEOFFB., DESMAB., 

 Loncheres myosurus (and leptosoma) LICHTENST., GUEB. Iconogr., Mammif. 

 PI. 24, fig. 3, WATEBH. Mamm. n. PI. 19, fig. 2. (Younger individuals, 

 that had not got spines, occasioned the adoption of a distinct species, 

 Echimys setosus GEOFFB., DESM., IBID. GEOFFB. 1. 1. PI. 25. Compare 

 PICTET Notice sur les Ani. nouv. du Mus. de Geneve, ire Livr. PI. i 3); 

 Loncheres antricola, Nelomys antricola LUND, Kongel. DansTce Vidensk. 

 SelsJcabs Afhandl. vin. 1841, PI. 23, &c. Individuals destitute of tail which 

 occur not unfrequently in South America amongst these rodents, the loss 



