Cratera steffeni

Cratera steffeni is a species of land planarian belonging to the subfamily Geoplaninae. It is found in Rio Grande do Sul, Brazil.

Description
Cratera steffeni is a flatworm that can reach up to 70 mm in length and 4 mm in width. The body is elongate with parallel margins; the front tip is rounded and the back tip is pointed. The dorsal side of the body has a broad orange band flanked on either side by black paramarginal stripes. The dorsal base color is a pale yellow, which can be seen on the margins. The ventral side is a pale yellow as well.

Aside from its coloration and shape, it is distinguished from other members of Cratera by having dorsal eyes restricted to lateral bands, a conspicuous glandular margin with four types of secretory cells, a bell-shaped pharynx, a short esophagus, the anteriormost testes being posterior to the ovaries, sperm ducts that open laterally into the proximal portion of the prostatic vesicle, an extrabulbar, unpaired prostatic vesicle with a tubular distal portion and an ample proximal portion, ovovitelline ducts that emerge dorsolaterally from the back half of the ovaries and ascend laterally to the female atrium, a short common ovovitelline duct, a long, dorso-anteriorly curved vagina, equal atria lengths, and a lack of folds separating the male and female atria.

Etymology
The specific epithet, steffeni, was given in honor of naturalist MSc. Clemente José Steffen S.J., for his "relevant contribution to the ethnobotany in southern Brazil".