1909. _Sylvilagus aquaticus littoralis_ Nelson, N. Amer. Fauna, 29:273, August 31, type from Houma, Terrebonne Parish, Louisiana. _Range._--Swamps and marshes along Gulf Coast, wholly within Lower Austral Life-zone, below 50 ft., from Mobile Bay west to Matagordo Bay. Inland _Marginal records_.--Alabama: Blakely Island opposite Mobile (A. H. Howell, 1921:73). Mississippi: Bay St. Louis (Nelson, 1909:275). Louisiana: Rayne (Lowery, 1936:32); Hackberry (Nelson, 1909:275). Texas: Matagorda (Nelson, 1909:275). =Sylvilagus insonus= (Nelson) Omilteme Cottontail (See figure 39) 1904. _Lepus insonus_ Nelson, Proc. Biol. Soc. Washington, 17:103, May 18, type from Omilteme, Guerrero. Known from type locality only. 1909. _Sylvilagus insonus_, Lyon and Osgood, Bull. U. S. Nat. Mus., 62:34, January 28 (see Hershkovitz, Proc. U. S. Nat. Mus., 100:335, May 26, 1950, for allocation of _S. insonus_ to subgenus _Sylvilagus_ instead of to subgenus _Tapeti_). Total length, 435; tail, 42.5; hind foot, 95; ear from notch (dry), 61. Color grayish brown above and dingy (not white) below; tail dingy buffy below and dull rusty brown above. The collectors thought that the species was restricted to the forested parts of the Sierra Madre del Sur between 7000 and 10,000 feet altitude in the Mexican state of Guerrero. [Illustration: FIG. 43. Distribution of _Sylvilagus cunicularius_ and _Sylvilagus graysoni_. 1. _Sylvilagus cunicularius insolitas_ 2. _Sylvilagus cunicularius pacificus_ 3. _Sylvilagus cunicularius cunicularius_ 4. _Sylvilagus graysoni_ ] =Sylvilagus cunicularius= Mexican Cottontail Total length, 485-515; tail, 54-68; hind foot, 108-111; ear from notch (dry), 60-63. Pelage coarse; upper parts brownish gray; skull massive; posterior extensions of supraorbital processes varying from those that project free to those that have the tips, or tips and a considerable part of the processes, attached to the braincase. SYLVILAGUS CUNICULARIUS CUNICULARIUS (Waterhouse). 1848. _Lepus cunicularius_ Waterhouse, Nat. Hist. Mammalia, 2:132, type from Zacualpan (probably in state of México). 1909. _Sylvilagus cunicularius_, Nelson, N. Amer. Fauna, 29:239, August 31. 1890. _Lepus verae-crucis_ Thomas, Proc. Zool. Soc. London, p. 74, June, type from Las Vigas, Veracruz. _Marginal records_ (Nelson, 1909:241).--Hidalgo: Tulancingo. Veracruz: Las Vigas; Orizaba. Oaxaca: Mt. Zempoaltepec; Suchixtepec. Guerrero: Chilpancingo. Michoacán (Hall and Villa, 1949:469). Pátzcuaro; Tancítaro. SYLVILAGUS CUNICULARIUS INSOLITUS (J. A. Allen). 1890. _Lepus insolitus_ J. A. Allen, Bull. Amer. Mus. Nat. Hist., 3:189, December 10, type from plains of Colima, Jalisco. 1909. _Sylvilagus cunicularius insolitus_, Nelson, N. Amer. Fauna, 29:243, August 31.