_Orthogeomys grandis latifrons_ Merriam, 1895. N. Amer. Fauna, 8:178, January 31. Type from Guatemala, exact locality unknown.

_Orthogeomys grandis nelsoni_ Merriam, 1895. N. Amer. Fauna, 8:176, January 31. Type from Mt. Zempoaltepec, 8000 ft., Oaxaca.

_Orthogeomys grandis pluto_ Lawrence, 1933. Proc. New England Zool.

Club, 13:66, May 8. Type from Cerro Cantoral, north of Tegucigalpa, Honduras.

_Orthogeomys grandis scalops_ (Thomas, 1894). Ann. Mag. Nat. Hist., ser. 6, 13:437, May. Type from Tehuantepec, Oaxaca.

_Orthogeomys grandis soconuscensis_ Villa, 1949. a.n.a.l. Inst. Biol.

Univ. Nac. Mexico, 19:267, April 8. Type from Finca Experanza, 710 m., 45 km. (by road) NW Huixtla, Chiapas.

_Orthogeomys grandis guerrerensis_ Nelson and Goldman, 1930. Jour.

Mamm., 11:158, May 9. Type from El Limon, in valley of Rio de las Balsas approximately 20 mi. NW La Union, Guerrero.

_Orthogeomys cuniculus_ Elliot, 1905. Proc. Biol. Soc. Washington, 18:234, December 9. Type from Zanatepec, Oaxaca.

_Orthogeomys pygacanthus_ d.i.c.key, 1928. Proc. Biol. Soc. Washington, 41:9, February 1. Type from Cacaguatique, 3500 ft., Dept. San Miguel, El Salvador.

Subgenus =Heterogeomys= Merriam

1895. _Heterogeomys_ Merriam, N. Amer. Fauna, 8:179, January 21.

_Type._--_Geomys hispidus_ Le Conte, 1852, from near Jalapa, Veracruz.

_Chronologic range._--Late Pleistocene, Wisconsin deposits (San Josecito Cave local fauna, Nuevo Leon) to the Recent.

_Description._--Skull dolichocephalic (less so than in the other subgenera); zygomata more widely spreading than in _Orthogeomys_; ramus and angular process short; interorbital area noticeably constricted; frontals between orbits neither exceptionally broad or inflated; mesopterygoid fossa extending to level of posterior margin of M3; I having sulcus on inner third of anterior surface usually narrower than in subgenus _Orthogeomys_; enamel plate on posterior wall of P4 restricted to lingual half of loph; M3 distinctly biprismatic, posterior loph usually circ.u.mscribed by shallow inner re-entrant fold and outer deep fold well developed in all members of genus; posterior loph forming conspicuous heel longer than in subgenus _Orthogeomys_; occlusal length equal to or slightly less than combined lengths of M1-2; hair coa.r.s.e and hispid but never so spa.r.s.e as to impart appearance of nakedness.

_Referred species and subspecies._--Eleven taxa:

*_Orthogeomys onerosus_ (Russell, 1960). Univ. Kansas Publ., Mus.

Nat. Hist., 9 (21):544, January 14. Type from San Josecito Cave local fauna, Upper Pleistocene, Nuevo Leon.

_Orthogeomys hispidus cayoensis_ (Burt, 1937). Occ. Papers Mus.

Zool., Univ. Michigan, 365:1, December 16. Type from Mountain Pine Ridge, 12 mi. S El Cayo, British Honduras.

_Orthogeomys hispidus chiapensis_ (Nelson and Goldman, 1929). Proc.

Bio. Soc. Washington, 42:151, March 30. Type from Tenej.a.pa, 16 mi. NE San Cristobal, Chiapas.

_Orthogeomys hispidus concavas_ (Nelson and Goldman, 1929). Proc.

Biol. Soc. Washington, 42:148, March 30. Type from Pinal de Amoles, Queretaro.

_Orthogeomys hispidus hispidus_ (Le Conte, 1852). Proc. Acad. Nat.

Sci. Philadelphia, 6:158. Type from near Jalapa, Veracruz.

_Orthogeomys hispidus latirostris_ (Hall and Alvarez, 1961). a.n.a.l.

Escuela Nac. Ciencias Biol., 10:121, December 20. Type from Hacienda Tamiahua, Cabo Rojo, Veracruz.

_Orthogeomys hispidus negatus_ (Goodwin, 1953). Amer. Mus. Novit., 1620:1, May 4. Type from Gomez Ferias, 1300 ft., about 45 mi. S Ciudad Victoria, 10 km. W Pan American Highway, Tamaulipas.

_Orthogeomys hispidus tehuantepecus_ (Goldman, 1939). Jour.

Washington Acad. Sci., 29:174, April 15. Type from mountains 12 mi. NW Santo Domingo and about 60 mi. N Tehuantepec, 1600 ft., Oaxaca.

_Orthogeomys hispidus torridas_ (Merriam, 1895). N. Amer. Fauna, 8:183, January 31. Type from Chichicaxtle, Veracruz.

_Orthogeomys hispidus yucatanensis_ (Nelson and Goldman, 1929).

Proc. Biol. Soc. Washington, 42:150, March 30. Type from Campeche, Campeche.

_Orthogeomys lanius_ (Elliot, 1905). Proc. Biol. Soc. Washington, 18:235, December 9. Type from Xuchil, Veracruz.

Subgenus =Macrogeomys= Merriam

1895. _Macrogeomys_ Merriam, N. Amer. Fauna, 8:185, January 31.

_Type._--_Geomys heterodus_ Peters, 1865, from Costa Rica, exact locality unknown.

_Chronologic range._--Known only from the Recent.

_Description._--Skull dolichocephalic in varying degree (overlapping subgenera _Orthogeomys_ and _Heterogeomys_ in this respect); mandibles elongated, not spreading far laterally; angular processes decidedly short; breadth across zygomata in no instance significantly exceeding mastoid breadth; interorbital area strongly constricted; frontals between orbits slightly inflated laterally (especially in forms having more strongly dolichocephalic skulls); pos...o...b..tal prominence conspicuous; anterior margin of mesopterygoid fossa terminating well behind M3; I having narrow and deep sulcus entirely on inner third of anterior surface; enamel plate on posterior wall of P4 restricted to inner half of loph; M3 bilophodont (outer and inner re-entrant folds each circ.u.mscribing a loph), posterior loph remarkably elongated and forming p.r.o.nounced heel, length of crown more than combined lengths of M1-2; hair wooly in some individuals, harsh in others but seldom hispid, never so spa.r.s.e as in subgenus _Orthogeomys_; some species having white markings, especially on lumbar region and head.

_Referred species and subspecies._--Eleven taxa:

_Orthogeomys heterodus cartagoensis_ (Goodwin, 1943). Amer. Mus.

Novit., 1227:2, April 22. Type from Paso Ancho, Province Cartago, Costa Rica.

_Orthogeomys heterodus dolichocephalus_ (Merriam, 1895). N. Amer.

Fauna, 8:189, January 31. Type from San Jose, Costa Rica.

_Orthogeomys heterodus heterodus_ (Peters, 1865). Monatsb. preuss.

Acad. Wiss., Berlin, 1865:177. Type from Costa Rica, exact locality unknown.

_Orthogeomys cavator nigrescens_ (Goodwin, 1943). Amer. Mus. Novit., 1227:3, April 22. Type from El Muneco (Rio Navarro), 10 mi. S Cartago, 4000 ft., Province Cartago, Costa Rica.

_Orthogeomys cavator pansa_ (Bangs, 1902). Bull. Mus. Comp. Zool., 39:44, April. Type from Bogava (= Bugaba), 600 ft., Chiriqui, Panama.

_Orthogeomys dariensis_ (Goldman, 1912). Smithsonian Misc. Coll., 60(2):8, September 20. Type from Cana, 2000 ft., mountains of eastern Panama.

_Orthogeomys underwoodi_ (Osgood, 1931). Field Mus. Nat. Hist., Publ. 295, Zool. Ser., 185:143, Aug. 3. Type from Alto de Jabillo Pirris, between San Geronimo and Pozo Azul, western Costa Rica.

_Orthogeomys cherriei carlosensis_ (Goodwin, 1943). Amer. Mus.

Novit., 1227:3, April 22. Type from Cataratos, San Carlos, Alajuela, Costa Rica.

_Orthogeomys cherriei cherriei_ (J. A. Allen, 1893). Bull. Amer.

Mus. Nat. Hist., 5:337, December 16. Type from Santa Clara, Costa Rica.

_Orthogeomys cherriei costaricensis_ (Merriam, 1895). N. Amer.

Fauna, 8:192, January 31. Type from Pacuare, Costa Rica.