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BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL. 46(3)
Type Locality.Chihuahua. Lectotype by present designation: BMNH 1901-6-22-657; collected in 1880 by H. Hoge (Figs. 63-66). The lectotype is figured in Martens, pi. 7, fig. 21. Paralectotype a: BMNH 1901-6-22-658 (1 mature specimen; figured in Martens, pi. 7, fig. 20) (Fig. 67). Paralectotype p: BMNH 1901-6-22-658 (1 immature specimen) (Fig. 68-69). The paralectotypes have the same data as the lectotype.
Martens described this species from "Chihuahua". It is not clear whether the locality is the city or the state. Whether the species actually occurred in Cd. Chihuahua can no longer be determined. The city has expanded since from being a small pueblo of less than 1,500 people then to a vast metropolis of 750,000 people now, and nothing remains there that resembles a natural habitat that could harbor an Humboldtiana. The embryonic sculpture, which consists of coarse beaded transverse wrinkled threads, is very similar to Humboldtianaprin-ceps, suggesting that the provenance for the species is in or near Cd. Chihuahua.
Distribution. The provenance of Humboldtiana hogeana remains unknown. Pilsbry (1935: 2) cites a specimen from Chihuahua City, which he states is a topotype, but he presents no information about why he considers the city to be the type locality. The specimen (ANSP 162326) is a different species than H. hogeana because of its more elevated helicoid shell shape, its glossy periostracum, and its brighter and more discretely banded color pattern. Later Pilsbry (1948: 202) reported H. hogeana from northwestern Chihuahua in the Sierra Madre at 3.5 mi. [6 km] above Colonia Juarez. Specimens collected from there by Pilsbry are in the Florida Museum of Natural History (UF 185700, UF 10313 8). These represent an undescribed species. They remain undescribed until anatomical material becomes available.
Solem (1974: 363) stated that Humboldtiana hogeana was widely distributed in Chihuahua. This is based upon earlier reports in the literature. He cites no specimen records to substantiate the distribution.
Remarks. The lectotype and the paralectotype a appear to be mature because they each have a reflected peristome. The type specimens were collected in a fresh state, if not alive. Each of them has dried mucus deposits on the exterior surface or the aperture. The lectotype bears an aestivation ring on the upper side of the body whorl. The curvature of the ring matches the contour of the outer lip of the immature paralectotype P-
The relationship of this species is uncertain because of the absence of anatomical information. The shell differs from other Clydonacme by its smaller size,
coarser embryonic sculpture, higher aperture shape, and banding pattern. These characters are not sufficient to indicate relationships within the subgenus, and without anatomical information taxonomic relationships remain uncertain although the embryonic sculpture is similar to that of H. princeps.
Etymology. Named after H. Hoge, who collected the species while traveling in Mexico during 1879-1880.
Aglotrochus n. subgen. Type species. Humboldtiana tanymastyx n.
sp.
The shell is moderately large and depressed-heli-coid in shape. It is smooth and shiny. The embryonic whorls are sculptured with very fine, straight, transverse striations. The post-embryonic sculpture consists of incremental striations and wrinkles. Granular sculpture is absent. The color is light brown with three dark brown bands and numerous transverse white streaks. The genital atrium is moderately long. The penis is short and eccentrically clavate in shape. Internally the penis contains a large verge that is about half the length of the chamber. The epiphallus is relatively slender and is about equal to the length of the penis. The flagellum is very long and slender. It is equal to seven times the combined length of the penis + epiphallus. The vagina bears four dart-sacs with ds, the largest and ds4 the smallest. The dart-glands form a ring around the vagina immediately above the dart-sacs. The spermathecal duct is very long, being about as long as the flagellum and about 2.7 times the length of the uterus.
The type species is alone among known congeners because of the very fine transverse striations on the embryonic whorls.
Etymology. The name Aglotrochus (m.) is from the Classical Greek ayAma, splendor or beauty, and Tpo^oq, a ball. The name alludes to the appearance of the shell.
Humboldtiana tanymastix n. sp.
Diagnosis. Same as for the subgenus.
Shell (Figs. 70-75). The large shell is about 35-38 mm wide, depressed-helicoid in shape, and 0.73-0.82 times as high as wide. There are 4.0-4.2 rotund whorls that are separated by a moderately impressed suture. The periostracum is shiny. The ground color is light brown with three dark brown bands and numerous transverse white streaks. The middle band is the widest and the darkest. The white streaks are irregularly spaced