76
BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL. 46(3)
H. titania n. sp., H. oberon n. sp., H. princeps n. sp., and H. hogeana (Martens, 1890).
The embryonic whorls are sculptured with of very fine wavy transverse striation and wrinkles (Figs. 31, 69). Fine granules may be superimposed on the wrinkles. The remainder of shell has incremental striations, and may be with or without fine granules on the first postembryonic whorl. The shell is elevated., with three discreet bands and occasional transverse white streaks on a light brown background. The slender penis has a short verge and heavy columnar fold internally. The penis retractor muscle forms a sheath around the lower part of the epiphallus. The flagellum is stout and moderately short. The dart-glands are closely appressed against the dart-sacs or they may be widely separated. The spermathecal duct is long and bears a short caecum near its end.
This subgenus is known from the Sierra de La Catarina and the Sierra Victorino in north-central Chihuahua, and from areas near Cd. Chihuahua.
Etymology. The name Clydonacme (f.) is from the Classical Greek, kA,i38oviov, a ripple, and axu, apex, alluding to the fine, wavy transverse striations on the embryonic whorls of the shell.
Species from the Sierra de La Catarina
The Sierra de La Catarina is inhabited by large-sized species that have starkly colored shell. As a group they are characterized anatomically by having a short nipple-like verge, the penis retractor muscle forms a broad sheath around the base of the epiphallus, the epiphallus is narrow and elongate, the genital atrium is very short and abbreviated, the middle vagina is abbreviated so that the dart-sacs are juxtapose to the dart glands, and the spermathecal duct is longer than the uterus-prostate.
Humboldtiana regula n. sp.
Diagnosis. The shell is medium sized, globose, and almost as high as wide. The periostracum is shiny light brown with three discreet chestnut-brown bands that frequently are crossed by enamel-white streaks. The embryonic whorls are raised, and sculptured with very fine, wavy, transverse striation. The postembryonic whorls are crossed by irregularly spaced incremental striations. The first postembryonic whorl has very fine elongate granules, which are absent on the following whorls. The genital atrium is very short. The penis is relatively slender. Its inner wall has four heavy longitudinal folds, and its apex bears a short verge. The penis retractor muscle is short and forms a sheath around the
lower fourth of epiphallus. The epiphallus is long and stout. The flagellum is short, being about as long as combined length of penis + epiphallus. The first dart-sac (ds,) is large. The other three dart-sacs progressively decreasing in size. The dart-gland are tightly appressed against the dart-sacs. The spermathecal duct is long and bears a short caecum below the spermathecal bulb.
Shell (Figs. 27-31). The shell is moderately large, about 29-33 mm wide, conical-globose in shape, and 0.83-1.00 times as high as wide. The periostracum is shiny. The ground color is light brown on the apex and becomes darker toward the aperture. The shell has three discreet chestnut-brown bands. The ground-color and bands are interrupted by frequent transverse enamel-white streaks. The interior of aperture is light brown and banded. Mature shells have 3.8-4.2 whorls. The suture is strongly impressed. The 1.4 embryonic whorls are moderately raised but flattened, and are crossed by fine wavy striations (fig. 31). The following postembryonic whorl has barely distinguishable minute granules that tend to be elongate and aligned between the incremental striations. The remaining whorls lack granular sculpture, but have irregular, distinct incremental striations that are exaggerated at the white streaks. The umbilicus is obliquely rimate and is nearly occluded by the reflected columellar lip. The aperture is rotund, 0.77-0.98 times as wide as high. The plane of aperture lies at 35-45 to the shell axis. The aperture strongly descends along the last quarter turn. The upper lip inserts just below, or on the lower edge of the lower band. The peristome is weakly reflected along the upper lip and strongly reflected along the columellar margin where it nearly obscures the umbilicus. The outer lip is not reflected.
Measurements in mm of the holotype and sixteen paratypes are given in Table 4.
Anatomy (Figs. 32-33). Two specimens were dissected (UF 317179). One is described below.
The genital atrium is very short. The slender penis is slightly swollen below its middle and is 8 mm long. The interior is lined with four large longitudinal glandular folds, and has a short verge that consists of a thin skirt of tissue (Fig. 33). The penis retractor muscle attaches to and envelops the lower forth of the epiphallus. It originates on the center of mantle floor slightly behind the mantle collar. The epiphallus is almost as stout as the penis and is about twice as long. The lumen of the epiphallus is lined with four longitudinal folds. The flagellum is relatively stout and moderately short, 30 mm long. It is slightly longer than the combined length of the penis + epiphallus. The interior of flagellum is lined with about six longitudinal columns. The lower vagina above