90
BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL. 46(3)
type: UF 350039; collected 23 November, 1970 by Fred G. Thompson. Paratypes: 21330 (4), 21331 (7), ITCV (4); same data as the holotype.
Snails were collected from crevices in a granite bluff along the south side of the stream below the Presa Chihuahua. The area was in a submesic forest consisting of a dense growths of thorn scrub above, below and on the side of the bluff.
Distribution. Known only from the type locality.
Remarks. The shell of Humboldtiana princeps is highly variable in shape and in the width of the bands. Usually the lower band is the widest, but not always. The subsutural reddish zone is absent in one live-collected paratype.
Etymology. The species name princeps is from Latin, meaning first among many, such as a prince or princess. The name alludes to the princely appearance of this snail.
Humboldtiana hogeana (Martens, 1892)
Helix humboldtiana hogeana Martens, 1892: 148; pi.
7, figs. 20,21 (shell). Humboldtiana hogeana (Martens). Pilsbry, 1927: 179.- Pilsbry, 1935a; Nautilus, 48: 2; pi. 1, fig. 9 (shell).Pilsbry, 1935b: 2; pi. 1, fig. 9 (shell).- Pilsbry, 1939:402.- Pilsbry, 1948:202.- Solem, 1954:5.- Th ompson, 1967:25.
Diagnosis. The following description is based on the syntypes, which are the only known specimens. A small-sized Humboldtiana that is up to about 33 mm wide with a helicoid-shaped shell that is 0.78-0.80 times as high as wide. The aperture is obovate in shape, and is higher than wide. The shell is lusterless, light brown in color with transverse white streaks and three reddish-brown bands. The middle band is the narrowest. The embryonic whorls are smaller than in other species in the subgenus. The embryonic sculpture consisting of
distinct transverse zigzag striations. The postembryonic sculpture consists of incremental striation and weak growth wrinkles. The second-half postembryonic whorl bears fine granules.
Shell (Figs. 63-69). A relatively small-sized species that is up to about 33 mm wide with a helicoid-shaped shell that is 0.78-0.80 times as high as wide. The periostracum is lusterless. The ground color is light brown with three reddish-brown bands. The middle band is the narrowest, and the sub-peripheral band is the widest. The shell bears transverse white streaks that are located on incremental growth striations. The white streaks are not as crowded as in other species in the subgenus. The interior of aperture is light brown with a whitish tinge and banded. The peristome is light brown. Rimate (Fig. 65). The aperture is obovate in shape, and is 0.82 times as wide as high. There are 3.8-3.9 whorls at maturity. Embryonic whorls 1.5. The first embryonic whorl is 3.7 mm wide perpendicular to the initial suture. The embryonic sculpture consists of relatively coarse and well defined beaded zigzag striations (Fig. 69). The following 1/4-1/2 postembryonic whorl bears incremental striation and wrinkles. The next half whorl has in addition, dense fine granules on and between the wrinkles. The remainder of the shell is sculpted with incremental striations and low wrinkles that continue over the surface and into the umbilical chink, but lacks granular sculpture. The whorls are rotund with a moderately impressed suture. They regularly expand in size along the upper edge of the middle band. The last l/8th whorl descends to the aperture at the upper edge of the sub-peripheral band. The plane of the aperture lies at an angle of 43-48 to the shell axis (Fig. 66). The aperture is obovate in shape and is 0.82 times as wide as high. The peristome is weakly reflected along the upper, outer and basal lips and then expands broadly to nearly occlude the umbilical perforation.
Measurements of the lectotype and the mature paralectotype are as given in Table 9.
Table 8. Humboldtiana priceps n. sp. Measurements in mm of the holotype (UF 350039) and 12 paratypes.
H W AW AH Whorls H/W AW/W AH/H AW/AH
Holotype 37.2 38.8 22.5 29.6 4.2 0.96 0.58 0.80 0.76
Paratypes
Min. 31.6 33.2 18.4 23.0 4.0 0.83 0.54 0.73 0.76
Max 37.2 41.0 23.2 28.4 4.1 0.91 0.57 0.76 0.84
Avg 34.29 37.58 21.27 26.50 4.06 0.91 0.57 0.77 0.80
SD 1.53 2.31 1.57 1.98 0.06 0.05 0.01 0.04 0.02