120 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 69 



Subfamily LONCHERINAE. Spiny Rats 



The subfamily includes three genera now known* to enter Panama, 

 Diplomys, Proechimys and Hoplomys. They are all rather large rat- 

 like animals with grooved spines or bristles mingled with the hair, 

 especially of the back. 



Genus PROECHIMYS Allen. Spiny Rats 

 The genus Proechimys is similar to the genus Hoplomys, but the 

 dorsal spines are much weaker. The ears are nearly naked as in that 

 genus — not conspicuously tufted as in Diplomys. The long supra- 

 orbital vibrissae of Hoplomys are replaced by short, inconspicuous 

 hairs. The normally long tail, subject to accident as in Hoplomys, is 

 thinly haired. The molariform teeth are cylindrical in form as in 

 Hoplomys — not elongated antero-posteriorly as in Diplomys. As in 

 the former genus the transverse grooves are shallow and through 

 progressive wear and partial obliteration soon divide to form irregu- 

 lar enamel islands. The claws are long, nearly straight, and asso- 

 ciated with terrestrial habits. 



PROECHIMYS SEMISPINOSUS PANAMENSIS Thomas 

 Panama Spiny Rat ; Macangue 



Proechimys centralis panamensis Thomas, Ann. Mag. Nat. Hist., Ser. 7, 

 Vol. 5, p. 220, February, 1900. Type from Savanna of Panama (near 

 city of Panama), Panama. 



Proechimys centralis chiriquinus Thomas, Ann. Mag. Nat. Hist., Ser. 7, 

 Vol. 5, p. 220, February, 1900. Type from Bugaba, Chiriqui, Panama. 



Two Panama forms of Proechimys were described by Mr. Oldfield 

 Thomas as geographic races of P. centralis Thomas, of Nicaragua. 

 Comparisons show that all of the known Middle American members 

 of the genus differ slightly from each other and some of them are 

 scarcely distinguishable from P. semispinosus Tomes, of Ecuador. 

 In view of the evident close alliance the Middle American series may 

 be assigned to that species, 1 unless it proves to be typified by an 

 earlier described form. It is interesting to note, in this connection, 

 that the Nicaragua animal was identified with Tomes' species by 

 Dr. F. W. True 2 in 1889. 



1 The forms should therefore stand subspecifically as follows : 



Proechimys semispinosus semispinosus Tomes, Ecuador. 



Proechimys semispinosus panamensis Thomas, City of Panama, Panama. 



Proechimys semispinosus burrus Bangs, San Miguel Island, Panama. 



Proechimys semispinosus rubellus Hollister, Pacuare, Costa Rica. 



Proechimys semispinosus centralis Thomas, San Emilio, Nicaragua. 

 1 Proc. U. S. Nat. Mus., Vol. 11 (1888) 1889, p. 467. 



